Sign in to follow this  
w1spurgeon

'36 Ford electrical problem

Recommended Posts

Wow this problem has me scratching my head. The car is a 6V+grd '36 Ford tudor standard with a 1-wire GM alternator and electronic ignition on a '47 flathead engine. I use a 8V battery to fire the ignition and seperate a 12V battery in the starter circuit. The two systems are isolated by a selonoid. It was running a few months ago, until I garaged it to rework the carb linkage, After completing the work I reconnected the ground wire to the battery and drew a major spark. I had smoke under the dash and fried some wiring, which I replaced on an individual basis. Now, when the wire to the alternator is not connected, the car starts and runs normally. When the alternator is connected it apparently shorts the battery directly to ground and I again get the large spark when I touch the ground wire to the battery. I assumed there would be a ground somewhere in the charging circuit so I tore it apart and guess what, no short to ground. Not in the wire to the alternator, not on the alternator terminal lug and not under the dash. One solution would to be to replace the dash to engine harness but theres no assurance that would solve the problem and besides, this has become a challenge I'd really like to figure out myself. Any suggestions would be helpful.

Share this post


Link to post
Share on other sites

Looks like nobody is going to jump in on this. So here is my opinion.

Lose the 12 volt starting circuit. lose the GM alternator, lose the 8 volt battery. Get a new wiring harness from a supplier like Rhode Island Electric, Ron Francis Wire Works, Painless Wiring, etc. Get the proper voltage regulator for your new generator. Get a 6 volt Optima battery, a little pricey but worth it. Get the proper size 6 volt battery cables. If your local NAPA or such does not have them go to a truck or tractor parts store. Get a Ford generator that fits your 42 thru 48 engine intake manifold and belt that fits you water pumps and crank pully. Your engine originally used 5/8 inch wide v belt and 49 and later used 1/2 wide v belt. If yours have the narrow belt someone changed the water pumps.

If everything is right with your 6 volt system it will work perfectly. Millions of flathead Ford, Mercury V8's and Lincoln V12's and V8's, and othr brands, worked excellent with 6 volt systems. No reason yours won't work the same.

I can understand using a 12 volt system if you're building a hot rod or street rod from the ground up, but, I don't understand people wanting to change a perfectly good 6 volt system just to be "up to date". The only udate it can use is the Optima gel cell battery over the wet cell battery.

Edited by Bob Call (see edit history)

Share this post


Link to post
Share on other sites

+1 for what Bob said. Why do you have two circuits running? How does the 12 volt battery stay charged? I'm willing to bet your problem is either in the solenoid or the alternator, and honestly, that sounds like a needlessly complex system for such a simple car. An 8-volt battery is a band-aid fix for things like bad grounds and undersized battery cables, and these cars don't need 12-volt starting systems to be reliable. The guys who say you need to do it are flat-out wrong. My '29 Cadillac starts as quickly as my fuel injected modern car with an original 6V system, and every 6V car we have in our inventory fires and runs as it should. The ones that give us headaches and have equipment that doesn't work and cobby wiring are all converted to 12V and it absolutely kills value and sometimes even reliability.

With the wiring you have cobbled together, finding your problem will be a challenge. If you're not ready to step up to a new wiring harness, at least get rid of the 12-volt system for starting, ditch the solenoid that isolates it, and try starting/running the car on the 8-volt setup alone. I bet doing that will solve your problem, but I will still encourage you to go back to 6-volts. Your light bulbs, starter, and other electrical systems will thank you.

Trust the factory engineers--they were smart guys. Put it the way it was supposed to be, use an Optima battery and extra large cables, and I bet your problems vanish.

Good luck!

Share this post


Link to post
Share on other sites

Thanks for your opinions but the biggest mistake I made in this building this car was to allow purists to talk me out of converting the car to a 12V system when I was just starting. The car is not original, will never be original and I wouldn't have it original. It's a resto-rod. The car has an electronic ignition, juice brakes, an Isky cam and Edelbrock Super manifold with two Edelbrock 94's because that's the way I want it and I'm looking to make it work, not change it back to where I started.

Now, having said that, I should explain I started with a new 6V Optima battery but changed to 8V because the Optima voltage output was not high enough to fire the electronic ignition. The 12V battery is charged on a battery minder while the car is parked in the garage. The car has the proper 6V sized cables and extra grounds vetween every major mechanical component.

Matt - I'm gonna try your suggestion to switch everything to the 8V system to see how that works. That soulds reasonable. The 12V system was originally installed because the engine had just come from the machine shop and was so tight the 6V system wouldn't turn it over fast enough to start. I had 50psi oil pressure at idle....that's tight.

Edited by w1spurgeon (see edit history)

Share this post


Link to post
Share on other sites

It seems that you have made a hybrid as "you would want it"- now you can have the pleasure of figuring out your creation. Coming to a site of "purists" for answers to a standard setup will not help, especially if you don't want to change anything. ;^)

Share this post


Link to post
Share on other sites

My local AACA group has as many hotrodders as restorers - we get along just fine. However I have to admit that your snotty response was not what I expected from this forum.

Share this post


Link to post
Share on other sites

By profession, I am an electronics technician, repairing consumer electronics. When I am repairing an item, I can use logic to trace out a problem to accomplish the repair. There is nothing worse than getting into an item, and trying to repair something that someone else has been into and made some "changes". Logic is thrown out the window! I'm afraid that the same goes for your car, and the set up it has.

It would be very difficult to recommend opinions on how to accomplish the repairs, when we have no idea how this set up is, especially when we are a group of "purists" that concentrate on originality. Your efforts would be better served by asking those who specialize in this type of set up, and who have done these conversions before. You might want to try the H.A.M.B. forums. They are a good bunch of guys, but primarily deal with conversions, hot-rods, etc..

Understand, I'm not trying to be a snob to you in any way, I just feel that with the type of setup you have, it would be better for you to talk to a group that understands what this conversion entails, and would have a better understanding on troubleshooting this type of problem.

Share this post


Link to post
Share on other sites

Thanks JIM, I agree. BTW, I am also a trained electronics technician (U.S. Navy) and worked in that field for 12 years before moving to management. My electronic skills are certainly outdated, but then so is the car.

SFAIR - The 12 volt system is not connected to the charging system in the car. It connects to a battery minder when the car is parked in the garage. The system has never given me any problems (at least before this) and has never failed to start the car when keyed. It has a seperate starter switch and the whole 12V system is isolated from the car charging system. The only way they can be connected together is if you press both starter switches (one on the floor, one under the dash) at the same time, bad news since that would deliver 20V throughout the entire system. This has not been done and has been eliminated as a potential cause of my problems. The 8V system is charged off the 6V alternator, which is not the best solution but has been operating satisfactorily for several months with the battery continuing to provide at least 7+ plus volts at all times. Remember the reason I went to an 8V battery was to deliver more than the 6V output of the Optima to the electronic ignition, so as long as it charges the battery to at least a 7V level, the charging system is working satisfactorily.

MATT - If you think the electrical system is overly complicated, you should see my throttle linkage. I gotta post some pictures.

Edited by w1spurgeon (see edit history)

Share this post


Link to post
Share on other sites

Why don't you convert the car completely to 12 volts if that is what you want? If you must have 6 volts for gauges, use a Runtz voltage drop, or a zener diode, or just take a center tap off the battery.

It sounds like you now have such a hodge podge even you can't figure it out, and you built it.

Share this post


Link to post
Share on other sites

OK, my last post on this subject. To those who suggest I should not have brought this up on a AACA forum I can only say that I have been a member for less that a year but I learn fast...and I have certainly learned my lesson. Look elsewher for help, look here for snotty replies and criticism. I guess the "Antique Auto" tag on my car isn't necessarily a pass into the AACA. The funny thing is that my car is entirely inspired by a beautifully restored Chrysler Airflow which runs around Chattanooga, beautifully restored except for the Chevy small block and auto transmission. An abomonation you say? Tell that to the owner. Personally I can't think of a finer fellow to emulate than Harold Coker.

Share this post


Link to post
Share on other sites
...Look elsewher for help, look here for snotty replies and criticism...

There have been replies suggesting you post your query on H.A.M.B. as that group is more in tune with, and receptive to, what you are attempting, and also that you eliminate the dual-voltage hodgepodge and convert the whole car to 12 vt.

These sound like valid and helpful suggestions.

Share this post


Link to post
Share on other sites

I don't think anyone was giving you a snotty attitude, we were offering fixes to a problem in a way that's consistent with the club's core philosophy on originality. You're the one getting defensive because we didn't tell you what you wanted to hear. Nobody is angry about what you did to your car, but the bottom line is that you pieced something together and are trying to make it run on three different voltages, only one of which is what the car was designed to run on, added a hodge-podge of flathead parts from various different years, plus some kind of aftermarket ignition which seems to be the whole reason you started getting creative with the electrical system in the first place. And you're still trying to make it work with a 6 volt alternator charging an 8 volt battery just so you can have 7 volts to drive the ignition system, never mind the 12 volt starter that has a battery that doesn't even charge itself as you drive, possibly leaving you stranded. Can you blame us for saying WTF, dude?

I think the only point anyone here was trying to make is that these cars ran properly on 6 volts when they were new, and there are still thousands of such cars doing so today. Nobody here cares if you installed multiple carburetors or a big cam or any other hop-up parts on your car, and they have nothing to do with the electrical system anyway. Your electrical upgrades are not necessary to make the car run properly, even with the modifications you've described, unless you've got some modern accessories such as a big stereo, A/C, or power equipment. Instead, what you have is a recipe for headaches, and you've got a big one with your hard starting issue. I think even the guys over at the HAMB are going to ask what the heck you're trying to do, and will most likely say convert the whole thing to 12 volts and be done with it, which is pretty much what we're saying--pick a voltage, convert the whole car to that system, and your problems should be solved. We don't care if it's 6 volts, 8 volts, or 12 volts, just that mixing and matching doesn't work, as you've discovered. And since you're the guy who put it together and it's not built to either factory or generally accepted specifications, it's very, very hard for us to diagnose a problem remotely over the internet. On the other hand, every single one of us will guarantee that if you put the electrical system back to stock specifications, the car WILL start and run properly, which is what we've all told you in one way or another. How can you argue with that?

Figuring this out is not something we can do easily, since there's not much stock electrical system left in the car. It's like me asking, "Hey, I have this 1936 Finster Fireburner that was the only one ever built, can anyone tell me how to install the front fenders? I cut them apart and welded them into a shape I like better and now they don't fit."

Or you can go to the HAMB and tell them what stuck-up snobs those AACA guys are, but I have a hunch they'll be a lot less polite to your situation than we've been. They usually don't tiptoe around the obvious like we do...

Edited by Matt Harwood (see edit history)

Share this post


Link to post
Share on other sites

w1spurgeon, I'm sure that you got the right training in electronics when you were in the service, but like you said, that was years ago. I've worked at the same repair shop for 35 years now, and even though I have always worked in this field, it's really hard to keep up with things the way things keep changing. I think I should have gotten a "real" job many years ago.:D

Good luck with your car, and I hope that you get thing straightened out. As suggested, the complete 12 volt conversion might be the best way to go, if you are not going to have it at 6 volts.

Share this post


Link to post
Share on other sites

A full 12 volt conversion will give you much less hassles then what you have now and can be made to look more period correct if you are worried about the purists looking at it,there are alternators made that look like generators and considering one for my 37 Chevy p/u that has a 57 235.

Share this post


Link to post
Share on other sites

You got a bunch of good, solid answers and one that might be construed as "snotty". Now your genitals are all tied in a knot and you castigate the entire forum. It is you that has an attitude. That being said, the 8/12 volt setup is dumb. Thousands of old Fords have been converted to 12 volt. The starters hold up just fine. Runtz converters or new 12V gauges will address the instruments. Everything else is a regular deal

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this