MrEarl Posted June 16, 2019 Share Posted June 16, 2019 Works fine on Lo and Med but not Hi. Worked for a while after complete AC replacement but stopped. It also didn't work when the "parts swapper garage" replaced the compressor. I know there is a wire running from the compressor to the blower relay and am wondering what association it has with the operation of the blower. I am considering replacing the relay but need to know if there is something else I need to consider. Just thought about this, maybe I should try it with AC off and heat on...... Link to comment Share on other sites More sharing options...
SpecialEducation Posted June 16, 2019 Share Posted June 16, 2019 No Hi is likely the relay. I’d jumper battery voltage to the blower to see what happens, then check for voltage in/out at the relay. Are any of the other relays the same part number so you can swap for diagnostics? If you lose a lower speed or two, that’s usually a resistor that’s burnt out, but Hi should be straight bus voltage. 2 Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted June 16, 2019 Share Posted June 16, 2019 33 minutes ago, SpecialEducation said: No Hi is likely the relay. I’d jumper battery voltage to the blower to see what happens, then check for voltage in/out at the relay. Are any of the other relays the same part number so you can swap for diagnostics? If you lose a lower speed or two, that’s usually a resistor that’s burnt out, but Hi should be straight bus voltage. Yep, my take as well. Ben Link to comment Share on other sites More sharing options...
avgwarhawk Posted June 16, 2019 Share Posted June 16, 2019 Blower motor high speed is direct 12 volts. If all other speeds are working the resistor is good. If only high is working then the resistor is bad. Check relay. Hopefully you do not need to get into the dash again to check the switch itself. 1 Link to comment Share on other sites More sharing options...
JohnD1956 Posted June 16, 2019 Share Posted June 16, 2019 Jiggle the fan switch on high. That's been my experience, A little to the left worked on my former '78 Link to comment Share on other sites More sharing options...
NTX5467 Posted June 16, 2019 Share Posted June 16, 2019 On many GM systems, there is a "high blower relay", which helps keep the dash blower switch from cooking over time. On some middle '70s systems, any time the selector lever was on "inside air", the blower automatically went to "HIGH", with an appropriate switch and wire on the control panel unit to do that. Unplugging that wire results in all blower speeds on outside air and "RECIR". Link to comment Share on other sites More sharing options...
JohnD1956 Posted June 17, 2019 Share Posted June 17, 2019 6 hours ago, NTX5467 said: On many GM systems, there is a "high blower relay", which helps keep the dash blower switch from cooking over time. On some middle '70s systems, any time the selector lever was on "inside air", the blower automatically went to "HIGH", with an appropriate switch and wire on the control panel unit to do that. Unplugging that wire results in all blower speeds on outside air and "RECIR". Thanks NTX...I need to do that on the Electra. That high speed on recirculate is way too noisy and lack of a lower speed on recirculate is way too much AC for comfort. Link to comment Share on other sites More sharing options...
MrEarl Posted June 17, 2019 Author Share Posted June 17, 2019 22 hours ago, avgwarhawk said: Check relay. Hopefully you do not need to get into the dash again to check the switch itself. Already pulled the top of dash off just to make sure I didn't disturb a wire while working on the coolant temp light. First thing I tried was jiggling the switch JD, no sweet spot found. I'm going to verify the part number and go ahead and order a new relay. My main concern was that it wasn't something associated with the compressor since there is that wire that comes off it and goes to the relay. Thanks guys for all the help, I'll report back how it goes. Link to comment Share on other sites More sharing options...
JohnD1956 Posted June 17, 2019 Share Posted June 17, 2019 @MrEarlBtw. Did you take temp readings with the infared gun during your trip to Jordan's? Just wondering how it compares to the trial tow readings? Link to comment Share on other sites More sharing options...
Frank DuVal Posted June 17, 2019 Share Posted June 17, 2019 16 hours ago, JohnD1956 said: That high speed on recirculate is way too noisy and lack of a lower speed on recirculate is way too much AC for comfort. This was part of the "Flow Through Ventilation" system. If the air is in recirculate, then there is no Flow Through Ventilation, so the designer made it only high speed so you would go for fresh air after set temperature was reached when starting the AC on Max in a hot car. This is to vent the cabin of unwanted fumes, either from the exhaust (deadly) or fellow passengers eating burritos.... (also deadly😁). Fresh air good, usually. This was a big improvement over the old car heaters that were recirculate only. And the cowl vent was an improvement over the fresh air intake at the grille in the early 50s that just sucked the exhaust from the car in front of yours in traffic.😨 Link to comment Share on other sites More sharing options...
MrEarl Posted June 17, 2019 Author Share Posted June 17, 2019 2 hours ago, JohnD1956 said: @MrEarlBtw. Did you take temp readings with the infared gun during your trip to Jordan's? Just wondering how it compares to the trial tow readings? I did. At midway point which happened to be where the high reading while in tow was made, upon arrival at Jordans and then at arrival bck home. Nothing higher than 195* and that was running at 65-70 in 88* temperate with AC on normal. I'm now taking reading at top of thermostat housing vs at base. I still plan on swapping out the radiator, water pump and thermostat. Doing some research on radiators at the moment Link to comment Share on other sites More sharing options...
JohnD1956 Posted June 17, 2019 Share Posted June 17, 2019 2 hours ago, Frank DuVal said: This was part of the "Flow Through Ventilation" system. If the air is in recirculate, then there is no Flow Through Ventilation, so the designer made it only high speed so you would go for fresh air after set temperature was reached when starting the AC on Max in a hot car. This is to vent the cabin of unwanted fumes, either from the exhaust (deadly) or fellow passengers eating burritos.... (also deadly😁). Fresh air good, usually. This was a big improvement over the old car heaters that were recirculate only. And the cowl vent was an improvement over the fresh air intake at the grille in the early 50s that just sucked the exhaust from the car in front of yours in traffic.😨 I was under the impression that the recirculate mode was not 100% recirculated air. It is mostly recirculated air with some fresh air percentage infused. Link to comment Share on other sites More sharing options...
JohnD1956 Posted June 17, 2019 Share Posted June 17, 2019 3 hours ago, MrEarl said: Nothing higher than 195* and that was running at 65-70 in 88* temperate with AC on normal. Maybe it would be a good thing to isolate the trans from the radiator by running one or two auxiliary coolers? Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 (edited) Not sure I'm following you. I have a transmission cooler in front of the radiator and behind the condenser. Are you saying it may be blocking air or transferring tranny heat to the radiator and to possibly move it or? I have heat sink type transmission cooler that I was planning on adding underneath the radiator shroud but have found the transmission temperatures to be in bounds. https://www.summitracing.com/parts/sum-331000 Edited June 18, 2019 by MrEarl (see edit history) Link to comment Share on other sites More sharing options...
JohnD1956 Posted June 18, 2019 Share Posted June 18, 2019 (edited) Well, if the engine temps were approaching 260 * while towing, but remain @ 195 * for several hours of highway driving without towing, then it seems to me that the towing is causing the trans to heat up and that is, in turn, heating up the engine by using the trans cooler in the radiator. And in that case, two separate auxiliary trans coolers piped in a tandum pattern in front of the condenser , and eliminating the trans cooler in the radiator as part of the system, should result in not much additional engine temps when towing. I am just thinking disconnect the trans lines at the radiator and plug the trans cooler ports with bolts. But I guess I would eventually remove that auxiliary cooler from between the condenser and radiator too. You have already changed this car for maximum efficiency while towing. I would not be concerned with originality at this point, but instead reliability. But that's just my point of view. And that heat sink looks interesting, but I would think the fore mounted trans coolers would be more efficient, and hardly visible inside that vast cavern between the grill and the condenser. And some of the reviews of the heat sink are not completely positive on the unit, although that seems to be more about the fit of the fittings. Hell, I'd even consider putting an electric pusher fan in front of those two prescribed trans coolers for even more airflow if stuck in traffic. I would not be pursuing a replacement radiator for one that held 195* steady for several hours of highway driving. Edited June 18, 2019 by JohnD1956 (see edit history) 1 Link to comment Share on other sites More sharing options...
NTX5467 Posted June 18, 2019 Share Posted June 18, 2019 Me suspects you'll need to get the carb checked for proper power mixture phasing and air/fuel ratio. How much throttle depression is needed when towing at 65mph on flat roads? How much on mild hills? Any trans downshifts? Does the cruise control maintain speed when towing? Might even need to get the distributor advance specs checked, too! What manifold vacuum at cruise empty and towing, to see if the vacuum advance still has vacuum in those conditions. Find some speed shop with a chassis dyno and get them to see what the air/fuel mixture at "road load cruise" and "max power". They might want to sell you some replacement Holley carb, which can be more tunable (easier for them) to replace the OEM QJet. There is a selection of power valve springs for the QJet, to vary when the power mixture on the primary metering rods happens. Just as there are a whole page full of primary and secondary metering rods, too. Check to make sure the plastic cam that raises the secondary metering rods has not worn or failed, too. GM's designs typically didn't have good baffles that channel all of the frontal air THROUGH the radiator. Usually gaps on the sides, by observation. Also make sure that if there is supposed to be an "air dam" hanging off of the bottom of the core support, to help air get through the radiator, that it's there. IS the lock-up torque converter still hooked up and working? Just curious. DO get a trans temp gauge, which can use a magnet to stick onto the bottom of the trans oil pan, just to see what the trans temp is. 270 degrees is the temp above which ATF deterioration usually starts with normal ATF. Syn ATF is a good bit higher. Just some thoughts, NTX5467 1 Link to comment Share on other sites More sharing options...
SpecialEducation Posted June 18, 2019 Share Posted June 18, 2019 Normally I’d recommend to always run transmission fluid through the radiator tank last to maintain consistent fluid temps. They work best in a certain temp range, and running the fluid too cool can be as bad as too hot. In your neighborhood, that’s probably not that big of an issue, though. Just helped my brother put a cooler on his ‘Burban. He lives in Nebraska and this is his daily, so it’s absolutely a big deal. 270°F may be where rapid fluid deterioration occurs, but long durations at 225° can be enough to cause significant breakdown. As a general rule, when ATF temps hit 200°F, it’s time to do something different. Do you still have the electronic carb on this car? 1 Link to comment Share on other sites More sharing options...
Frank DuVal Posted June 18, 2019 Share Posted June 18, 2019 6 hours ago, JohnD1956 said: I was under the impression that the recirculate mode was not 100% recirculated air. It is mostly recirculated air with some fresh air percentage infused. On my 70 Buick it is 100% recirculated air. All the evaporator boxes I have repaired on many models of cars the recirculate door seals off the intake of fresh air. I am not aware of any bypass route for fresh air to enter these evaporator boxes. A test would be to disconnect the fuse for the blower, put system in recirculate and see if any air comes through the vents just from driving the car at speed. Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 2 hours ago, JohnD1956 said: Well, if the engine temps were approaching 260 * while towing, but remain @ 195 * for several hours of highway driving without towing, then it seems to me that the towing is causing the trans to heat up and that is, in turn, heating up the engine by using the trans cooler in the radiator. And in that case, two separate auxiliary trans coolers piped in a tandum pattern in front of the condenser , and eliminating the trans cooler in the radiator as part of the system, should result in not much additional engine temps when towing. I am just thinking disconnect the trans lines at the radiator and plug the trans cooler ports with bolts. But I guess I would eventually remove that auxiliary cooler from between the condenser and radiator too. You have already changed this car for maximum efficiency while towing. I would not be concerned with originality at this point, but instead reliability. The heat sink unit was going to be used in addition to the unit between the rad and condenser before I realized I had a engine coolant temp while towing problem. Now considering removing the unit between the rad and condenser and adding a large one in front of the radiator. If I do that I'll definitely just go ahead and swap out the radiator with a 3 core, possibly aluminum. Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 48 minutes ago, NTX5467 said: Me suspects you'll need to get the carb checked for proper power mixture phasing and air/fuel ratio. How much throttle depression is needed when towing at 65mph on flat roads? How much on mild hills? Any trans downshifts? Does the cruise control maintain speed when towing? Might even need to get the distributor advance specs checked, too! What manifold vacuum at cruise empty and towing, to see if the vacuum advance still has vacuum in those conditions. Find some speed shop with a chassis dyno and get them to see what the air/fuel mixture at "road load cruise" and "max power". They might want to sell you some replacement Holley carb, which can be more tunable (easier for them) to replace the OEM QJet. There is a selection of power valve springs for the QJet, to vary when the power mixture on the primary metering rods happens. Just as there are a whole page full of primary and secondary metering rods, too. Check to make sure the plastic cam that raises the secondary metering rods has not worn or failed, too. I had a full tune up with new plugs, wires, set timing etc but am definitely not satisfied with the output of the engine so at SOME point will be looking into all that so wil get back to you on it. Thanks 52 minutes ago, NTX5467 said: M's designs typically didn't have good baffles that channel all of the frontal air THROUGH the radiator. Usually gaps on the sides, by observation. Also make sure that if there is supposed to be an "air dam" hanging off of the bottom of the core support, to help air get through the radiator, that it's there. Funny you mention that. I was looking at and measuring the radiator for replacement today and was astonished at all the gaps and space on the sides of the radiator where air could flow right through. Will definitely need attention when new radiator is installed. And yea the air dam is there. Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 37 minutes ago, SpecialEducation said: As a general rule, when ATF temps hit 200°F, it’s time to do something different. 👍That's my goal for towing. Link to comment Share on other sites More sharing options...
Ronnie Posted June 18, 2019 Share Posted June 18, 2019 What are the conditions when you notice the engine starts to overheat pulling the camper? What is the speed and RPM? Is it pulling really hard without the transmission downshifting? Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 3 hours ago, JohnD1956 said: You have already changed this car for maximum efficiency while towing. I would not be concerned with originality at this point, but instead reliability. Somewhat sadly you're right. Maybe I'll enter it in Modified next year in Ohio. 😊 1 Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 5 minutes ago, Ronnie said: What are the conditions when you notice the engine starts to overheat pulling the camper? What is the speed and RPM? Is it pulling really hard without the transmission downshifting? The only time I tested it was the day I took it to the scales for checking the weight distribution hitch set up. I went through a lot of STEEP Georgia hills and tried to maintain a speed of 60-70 so the engine was really reving most of the time. The tranny performed well, downshifting as should. Tranny temp was below 200 if I recall. That was the same day I had to get back home and get Rita to the ER so am a bit fuzzy in remembering details. Link to comment Share on other sites More sharing options...
Ronnie Posted June 18, 2019 Share Posted June 18, 2019 (edited) 2 hours ago, MrEarl said: The tranny performed well, downshifting as should. Well that blows my theory of what might be going on. A friend over the weekend was telling me his Ford truck with a 390 was overheating when pulling his enclosed race car trailer up the long steep hills we have here in East TN. He said the problem turned out to be the transmission wasn't downshifting properly and was lugging the engine too much. I thought that might be your problem. BTW, check the bottom radiator hose and make sure it is good. I've known old hoses to collapse and be sucked together when the engine is riving high and pulling hard. That will make one overheat. Make sure the reinforcing wire inside the hose isn't missing or damaged. Edited June 18, 2019 by Ronnie (see edit history) 1 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted June 18, 2019 Share Posted June 18, 2019 10 hours ago, MrEarl said: The heat sink unit was going to be used in addition to the unit between the rad and condenser before I realized I had a engine coolant temp while towing problem. Now considering removing the unit between the rad and condenser and adding a large one in front of the radiator. If I do that I'll definitely just go ahead and swap out the radiator with a 3 core, possibly aluminum. 3 core will serve you well. It did with my 73 Estate Wagon (college car, 455) that overheated quite a bit with the factory radiator. This included our families 73 Estate Wagon purchased new. GM should have known better. Anyway...for me, the installations would be from nose to tail: trans cooler, condenser, radiator. Some claim Water Wetter works in lowering temps. 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted June 18, 2019 Share Posted June 18, 2019 As a side note, the 3 core aluminum may be so efficient that an additional trans cooler my not be necessary. 1 Link to comment Share on other sites More sharing options...
SpecialEducation Posted June 18, 2019 Share Posted June 18, 2019 13 hours ago, MrEarl said: I had a full tune up with new plugs, wires, set timing etc but am definitely not satisfied with the output of the engine... Sounds like you need me to bring you an Olds 403 to put in it... 😁 Link to comment Share on other sites More sharing options...
Matt Harwood Posted June 18, 2019 Share Posted June 18, 2019 Don't the Olds 403s have overheating problems of their own? I seem to recall something about siamesed bores or something like that... As long as we're spending Mr. Earl's money, how about a built 455 with a 700R4 behind it? Keep it all Buick and give it the power to ignore hills and loaf along the interstates! Link to comment Share on other sites More sharing options...
SpecialEducation Posted June 18, 2019 Share Posted June 18, 2019 21 minutes ago, Matt Harwood said: Don't the Olds 403s have overheating problems of their own? I seem to recall something about siamesed bores or something like that... Meh... I keep hearing that, but we had a '77 Delta 88 with a 403/400 and pulled a camper with that thing everywhere. The only thing we ever cooked was the transmission. We only got rid of it because my brother bent it in the middle. 1 Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 (edited) 4 hours ago, SpecialEducation said: Sounds like you need me to bring you an Olds 403 to put in it... 😁 What would I do with two 403's? This one should be good to go, just doesn't have the power I would have thought it should. But tha's another thread..... 3 hours ago, Matt Harwood said: Don't the Olds 403s have overheating problems of their own? I seem to recall something about siamesed bores or something like that... Exactly and mine has had two head jobs already and precisely why I am trying to ensure it doesn't get another 3 hours ago, Matt Harwood said: As long as we're spending Mr. Earl's money, how about a built 455 with a 700R4 behind it? Why stop there, got a posi traction rear end to go with it? Edited June 18, 2019 by MrEarl (see edit history) Link to comment Share on other sites More sharing options...
MrEarl Posted June 18, 2019 Author Share Posted June 18, 2019 2 hours ago, SpecialEducation said: Meh... I keep hearing that, but we had a '77 Delta 88 with a 403/400 and pulled a camper with that thing everywhere. 403/400 ? Olds would have been a 403 right. Never thought I'd ever spend more time on Olds and TransAm sites than here but recently that has been the case. The emission controls back then really played havoc with the muscle car scene eh? Link to comment Share on other sites More sharing options...
Bloo Posted June 18, 2019 Share Posted June 18, 2019 (edited) 57 minutes ago, MrEarl said: The emission controls back then really played havoc with the muscle car scene eh? Yeah, but not so much what people think. For the most part it wasn't all the little valves and pumps and hoses that caused that, it was low compression, and suboptimal cam and ignition timing. Edited June 18, 2019 by Bloo (see edit history) 2 Link to comment Share on other sites More sharing options...
SpecialEducation Posted June 19, 2019 Share Posted June 19, 2019 13 hours ago, MrEarl said: 403/400 ? Olds would have been a 403 right. Never thought I'd ever spend more time on Olds and TransAm sites than here but recently that has been the case. The emission controls back then really played havoc with the muscle car scene eh? Sorry, I’m saying that we had the 403 Olds with the THM400 transmission. Did we ever figure out what rear end you have? The 403 is pretty potent, so if you think it’s lethargic, it may just be a gearing issue. Funny you should mention T/As. I’ve got a spare 403 that a friend pulled from a ‘79 so he could drop in a Poncho 400. He says it was a wasted effort. Not worth the time/money he spent scrounging up parts. Perhaps @Ben Bruce aka First Born needs to come down and help you install fuel injection? 🤣 1 Link to comment Share on other sites More sharing options...
MrEarl Posted June 19, 2019 Author Share Posted June 19, 2019 21 minutes ago, SpecialEducation said: Did we ever figure out what rear end you have? The 403 is pretty potent, so if you think it’s lethargic, it may just be a gearing issue. a th350 and 3.23 Limited Slip 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted June 19, 2019 Share Posted June 19, 2019 15 hours ago, MrEarl said: . The emission controls back then really played havoc with the muscle car scene eh? Castrated comes to mind. Link to comment Share on other sites More sharing options...
avgwarhawk Posted June 19, 2019 Share Posted June 19, 2019 According to the window sticker this Buick has the 5.7 350 Olds. Rated around 160 hp. Link to comment Share on other sites More sharing options...
MrEarl Posted June 19, 2019 Author Share Posted June 19, 2019 21 minutes ago, avgwarhawk said: According to the window sticker this Buick has the 5.7 350 Olds. Rated around 160 hp. That was standard, see the options list, about midway down Link to comment Share on other sites More sharing options...
Matt Harwood Posted June 19, 2019 Share Posted June 19, 2019 Wow, $4000 worth of options on a $7000 car is really significant. Talk about loaded! Nice! Link to comment Share on other sites More sharing options...
avgwarhawk Posted June 19, 2019 Share Posted June 19, 2019 1 hour ago, MrEarl said: That was standard, see the options list, about midway down Got it! 403 hp is 185 if my research is correct. Link to comment Share on other sites More sharing options...
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