NCCT Posted March 29, 2021 Share Posted March 29, 2021 Hello everyone, I'm a new owner of a 1927 Hudson which I have been using for a few months now. I love the car but have been experiencing a strange problem.The car will intermittently lose power. I say intermittently because I could put 100 miles on it and it doesn't have a problem until the next time I use the car. Or the other scenario is that I use the car and have power loss 2 days in a row after using the car for an hour each day. Its never consitent but I will say that it seems to be happening more often now (getting worse)Ill explain the power loss issue in detail as well. This car has a rebuilt starter, rebuilt generator, new generator cutoff, new points, new coil, new optima red top 6v battery. (I have NOT changed the condeser out yet because I cant find that flat square condenser that fits in the slot.....anyone know where I can get one? lol)The car will be driving along for an indiscriminate amount of time when all of a sudden the car starts losing power, backfiring, running rough, etc etc. So... clearly its losing spark. Once this starts I know I'm in trouble and if the car stalls or if I drive it too much longer (the car will shut off) I will not be able to restart the car because the battery will be flat dead. Sometimes less than 4 volts when checked with a meter. I can then immediately change to another fully charged 6v optima and the car will start right up, run and drive for another indiscriminate amount of time until the problem occurs again sometime down the road. Maybe two hours later, maybe 2 weeks, 10 miles, 50 miles. Doesnt seem to matter. Any thoughts? Thank you very very much for your helpKen Link to comment Share on other sites More sharing options...
nickelroadster Posted March 29, 2021 Share Posted March 29, 2021 I would check your generator and cutout. If you can put a fresh battery in and it starts and runs fine it sounds like the battery is not getting charged. 1 Link to comment Share on other sites More sharing options...
certjeff1 Posted March 29, 2021 Share Posted March 29, 2021 I agree start with checking the charging system. If an engine dies while driving and the battery is dead and will not operate the starter. Start by checking the charge rate. 1 Link to comment Share on other sites More sharing options...
NCCT Posted March 29, 2021 Author Share Posted March 29, 2021 I will put a meter on it today and see what the meter says at the generator. I will report back 1 Link to comment Share on other sites More sharing options...
Bud Tierney Posted March 29, 2021 Share Posted March 29, 2021 (edited) Hey, these old cars had an ammeter---what's it been saying?? Or had Hudson already gone to on idiot light, like my old 36??? Can't recall what the 34 Tearapieces or the 35 Coupe had,,,all long gone... Edited March 29, 2021 by Bud Tierney Typing (see edit history) 1 Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted March 29, 2021 Share Posted March 29, 2021 10 hours ago, NCCT said: I will put a meter on it today and see what the meter says at the generator. I will report back While you are measuring, also measure the current at the battery. This way we will know the total current available (at generator) and the current going into or out of the battery. With these numbers we will have a much better picture of what may be happening. Also, with a generator charging system, rpm is a very big part of the picture. Repeat all measurements at various engine rpm. Of the most important are the rpm where the charge current at the generator is the highest and at an estimated average driving rpm. The driving rpm is the hardest to estimate AND the most important, unfortunately. Just take an honest best guess for the driving rpm based on where the most of your driving takes place, in town or on open roads. The reason this is important is that the charge rate is normally set on cars of your vintage by trial and error after a mid range starting place. Driving habits greatly effect charging on old cars!! Keep us posted... 1 Link to comment Share on other sites More sharing options...
Bloo Posted March 29, 2021 Share Posted March 29, 2021 A charged battery is about 6.3 volts. You should not really be seeing less that this going down the road. Something more like 7 or 7.5 volts you might see, but it is really hard to predict because I suspect this car has no voltage regulator. if it is dropping below 6.3 while you are out driving with the lights shut off, measured while running (not just idling), then it is safe to say it is not charging at all. 1 Link to comment Share on other sites More sharing options...
NCCT Posted March 30, 2021 Author Share Posted March 30, 2021 Alright so I figured it out! Come to find out its something to do with the ammeter. Generator was good, cutout was good, but battery wasnt charging. Ammeter was wired backwards so it was acting as a diode . electricity couldnt pass through so it wasnt getting to the battery. Bypassed it with a wire from cutout to battery and bingo! Shes charging very well. How about that!? Lol 1 Link to comment Share on other sites More sharing options...
certjeff1 Posted March 30, 2021 Share Posted March 30, 2021 If an ammeter is wired backwards then you will show charge when discharging and discharging when charging. Meaning when you are cranking the engine the ammeter will show a charge. This usually happens when people convert from positive to negative ground or vice versa. Ammeters are like water meters the current flows thru them so when they go bad you get a no charge situation. 1 Link to comment Share on other sites More sharing options...
Frank DuVal Posted March 30, 2021 Share Posted March 30, 2021 4 hours ago, NCCT said: so it was acting as a diode Highly doubt that was happening. It is just a piece of wire with another coil of wire wrapped around it. Current flows BOTH ways (not at the exact same time, though) in normal ammeter use! That's why there is a D (discharge) and a C (Charge) end of the scale with a center 0 (zero). Just sounds like the ammeter had an "open" circuit internally. Link to comment Share on other sites More sharing options...
NCCT Posted March 30, 2021 Author Share Posted March 30, 2021 (edited) I guess I should have worded it this way. It seems that something in the ammeter was causing it to act as a diode. The meter did in favt show a discharge when the car was running but no electricity was exiting the ammeter. So.....in turn....blocking electricity (like a diode does). The electricity was going ONE WAY. from the battery. Nothing was actually going INTO the battery. Even though the needle in the meter moved NOTHING got past it and into the battery. Edited March 30, 2021 by NCCT (see edit history) Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted April 1, 2021 Share Posted April 1, 2021 @NCCT, Please follow up on this when you get things working properly. As said above, it is virtually impossible for an ammeter to do what you describe. I am sure you are going to find more wrong as you continue forward with this repair. It will be very interesting to hear what you find. To prove or disprove what you have found, please make the following test... With ALL wires disconnected from the ammeter make the following resistance measurements: Measure resistance (ohms) between the two ammeter terminals, Then reverse the test meter leads and repeat the measurement. Please post your findings. I expect that the measurements will be virtually the same, but who knows,,, Link to comment Share on other sites More sharing options...
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