Hey all, I am trying to solve a charging problem in the Av8 coupe I have a flathead with a alternator in the generator case and external voltage regulator. The battery at rest is read 12.4V (I have the charger on it as it may not be fully charged from the troubleshooting I have been doing. When the car is running I am reading 11.9v @about 1200rpm when i turn on the lights that number drops to 11.6v I recently had a solenoid problem and replaced it with new, i suspected the voltage regulator as well because one of the contact assemblies was loose and the face of the contact had a big pit in it (see my earlier question about voltage regulator adjustment) Anyway, I couldn't find any answers so I just replaced the voltage regulator. But I still have the same charging condition. Now I am wondering if the alternator is working correctly. When I measure voltage from the output post to the housing or block I get about 0.17v The belt runs from the alt to water pumps and crank pulley. At the mid point between the alternator and the water pump I have about 1 inch of deflection I. Both directions in the belt. I know that if the belt is to tight it can cause premature wear on the pumps and cause them to start leaking. My question is...how tight is to tight? Is 1 inch deflection too much? Would a belt that loose cause my low voltage problem? Also, how do you pry the alternator up and hold it while you tighten the big bolt when trying to tighten the belt? As always, Thanks for the assistance Chappy 20180503_214527 by Chappy444 posted May 3, 2018 at 9:46 PM
Classic readings for a dead charging system. It is not charging at all. No, not with those readings you posted.
No squeal, it's a new belt. the whole car has less than 1000 miles on it. This all seemed to start when the solenoid acted up... (the starter would engage when I hit the battery disconnect) Would that have taken out the alternator? The alternator is the only piece left that hasn't been tested or replaced in the last few weeks
Would to little ground cause these same symptoms? (Full disclosure: I didnt build this car, I am just trying to get it sorted)
Who knows how that hidden alternator functions or is wired...or...how that and the key switch and solenoid were wired.. It is definitely possible the two issues are related, more likely than not. Crazy Steve is pretty up on strange "back feeds" and how to wire modified/or aftermarket things up the correct way. I am guessing here, but something "might" have gone wrong in the Alternator "first", which somehow then back-fed the solenoid, even with the key-off.
No key, just a battery disconnect on the pos cable between battery and solenoid, an on off switch (think 40 ford column drop), and a push button starter. Pretty simple layout...very basic...just lights and turn signals... 12v neg ground..
If your solenoid let go while cranking, then it's getting it's juice from the battery only (The alternator is not spinning fast enough for an output.) Remove the alternator and bench test it (you may have to take it to an auto elec, who has the bench set up with an external regulator, or you could set it up yourself). You will more than likely find that the alternator is toast, maybe just needs brushes and a slip ring skim.
Thanks for the info... I was really hoping this was not the case... And would like to figure out why it failed so fast... I hate treating symptoms... I would much rather solve the csuse. I guess now all I have to do is find some place competent enough to test it and or rebuild it...
My 32 with a 40 Ford Dash, and with a generator on the early olds motor, has the same "key", yes I know the key just locks the ign toggle switch, but it is still a switch. with such a basic "no frills" electrical system, I would have built that car with a generator. I cannot know what type of mods were done inside that old generator case... Any Alt or Gen makes HEAT...so 'if" that modified unit just plain runs too hot encased like it seems to be, that might be why it failed. Look up old time Auto Electrical Rebuilders ( like was said in the post above this one) in the phone book for your area. They could check it out if you take it off and bring it in. They should be able to look at the innards, and see if they think it was overheated, maybe by the design of a "hidden" unit?...perhaps..
Really sounds like a bad alternator or diodes. You can test it yourself by jumpering between the battery terminal and the terminal that goes to the slip ring (which is usually marked 'F') at the regulator. If output goes up, it's the regulator; if not, it's the alternator. And you have made sure all the wires between are good, right? One broken internally would do this. One issue with those alternator-in-a-generator-case units is a lack of cooling. Another is they're current-limited as there's simply not enough room in them to install bigger diodes. And you don't say what size of load is on it; these are known to fail if overloaded. They really should build those 'generator/alternators' with the rectifier external to the unit; they could increase output and cure the heat problem, but you would have a 'box' you'd have to hide....
Re belt tension; I have always been told 1”-1&1/2” deflection. I probably run a little on the slack side, rather than too tight.
Thanks Clem! 1" deflection "felt" right when pushed on the belt (if I really push on it I can get it to go to almost 1.5")...but this is my first flathead so I wanted to make sure.
As long as things are still charging and water pumps are still turning. I run a ‘b’ belt, gives more surface area to contact on the pulleys, so in theory less slip than an ‘a’ belt for same amount of belt tension.
Thanks for all the help guys. I have found a shop that is open tomorrow. The guy in the shop said they could test the alternator and he is interested to see a alternator in a generator case... didnt give me a warm fuzzy feeling, we will see. Quoated me about $50 to rebuild... Anyone familiar with P&H auto-electric (Dynathrust) out of Baltimore, MD?
Well...the saga continues, After finally contacting the previous owner of the car I find out that it is not a alt in a gen case but a 12v gen upgrade that is on the car...after having it tested this morning at a auto electrical shop it is working fine (35A output) So i have replace the solenoid and voltage regulator. I have had the generator and battery tested and both are in good working order... why am I not getting any charge at the battery (car starts and runs fine) Out to the garage later to put the gem back in and look for other sources for this issue. Stay tuned ...
I adjust belt tension by trying to turn the generator. If the belt slips, it's too loose. As for your system problem, take the whole vehicle to the shop that tested the generator for you. You sometimes have to polarize the system. https://www.jalopyjournal.com/forum/threads/polarizing-your-ford-generator.103849/
Update with resolution! We have charging! After finding out that the car had a 12v generator and not a 12v alt in a gen case things got a bit simpler. After having the generator tested I came home and verified all of my connections and installed the generator and polarized the system by powering on the car with the field wire (FLD) disconnected from the voltage regulator, then tapping it quickly to the Battery (BAT) terminal. I saw a small greenish blue spark and then I turned the power off and connected the Field wire back to the field terminal, started the car and had about 14.3volts charging at the battery. Not sure if it was the polarization, or a loose/bad connection that was giving me fits but it seems to be resolved now. Now if I could figure out how it lost polarization in the first place.... Thanks to everyone for the input and assistance. Chappy
Changing or removing any component including the battery can result in loss of polarization. Thanks for reporting back on the solution. Enjoy driving it now.
Disconnecting the battery shouldn't. Hesitate to say "can't", but it isn't supposed to. Removal of the generator itself, or regulator, or wiring, shouldn't either. Disassembly of the generator itself will, sitting unused for a long time will. Dropping a magnet on a hard surface will mess them up or weaken them, so dropping the generator on your big toe, it may need polarization (after you get back from the hospital) I'm surprised our sharp eyed H.A.M.B. readers didn't notice, that must be a genu-ine generator, as you can plainly see the commutator and brushes in that pic. Speaking of, you should polish up that commutator with some sandpaper. Make sure the brushes move freely and make good contact. Good clean tight grounds and connections are important for any charging system. Regulator too. The points inside the regulator too need attention now and then for happy electrons.
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