IGNITION TROUBLES! I'm stumped.

Not George

Not George

Senior Member
Hi guys,
Before I get too far along let me start by saying I have been to Bert's, I just don't want to go back for a third time today.
When I got the car it had no generator. Since I will be driving the car I opted for an alternator. After installing the alternator, when you hook up the battery, the amp meter pegs immediately. Left long enough it will smoke. Steve let me take home a second alternator to check. Same thing.
My headlight/taillight harness is un hooked, I have re placed the dash harness and generator harness,armored cable, ignition switch and starter switch.
The only other things left in this circuit are the distributor,and the coil.
I have insulated the lower plate behind where the armored cable screws into the distributor so it won't short on the case.
I don't believe it is the distributor or coil because it will run fine with the alternator disconnected.
Any help would be greatly appreciated. Thanks
 
Could the horn wiring be shorting? According the wiring diagram, that might be disconnected when you remove the alternator.

ModelAwiringdiagram-FloydClymer.jpg


Steve
 
You mean the ammeter is showing full discharge even without starting the engine? So the alternator isn't even turning? That sounds like a short inside the alternator. I have bought rebuilt alternators that had shorts right out of the box; it's not really uncommon.
 
If the wrong polarity is hooked to the alternator it will peg the ammeter and if left long enough the wires and--or the alternator will smoke.

an alternator can be made either + ground,or- ground, some can be changed to work either way.

change the polarity or the ground and see if there is a spark (you probably had a good strong spark in your previous attempts), there shouldn't be a spark
 
Not George; most likely that alt. they sold you is positive ground, if it's 6 volt. Switch your battery around & see.
 
Arthur1958 said:
You mean the ammeter is showing full discharge even without starting the engine? So the alternator isn't even turning? That sounds like a short inside the alternator. I have bought rebuilt alternators that had shorts right out of the box; it's not really uncommon.
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It is showing full charge without the alternator turning.
 
I don't understand "insulated the lower plate" ?? What happens if you disc the alt and hook e/thing else up?? Does the amp peg now. You've also got to decide i/know if you're 6V+ or 6V-. Hopefully you've put a fuse in the circuit...............
Paul in CT
 
1931 flamingo said:
I don't understand "insulated the lower plate" ?? What happens if you disc the alt and hook e/thing else up?? Does the amp peg now. You've also got to decide i/know if you're 6V+ or 6V-. Hopefully you've put a fuse in the circuit...............
Paul in CT[/QUOTE
I have no fuse in the circuit. That is next on the list The engine starts and runs fine with the alternator disconnected.
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Like the others said it sounds like the alternator has incorrect polarity. Alternators have a series of diodes and a voltage regulator internally, that when connected with a reversed polarity become a short circuit. Most of the alternators I've seen for Model A's have a shorting bar, on the back side, that allows changing the polarity from positive to negative ground. Check with Bert's or whoever you got the alternator from.
 
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"Since I will be driving the car I opted for an alternator. "

There is no reason you can't drive the car with a generator. Thousands of people do it. Look at the trouble you're having by trying to put something on the car that wasn't there originally. Keep it stock. It'll work fine and it's easier to fix when it doesn't.
 
A properly rebuilt generator will last 100,000 miles if you adjust the 3rd brush properly or use an electronic voltage reg.Iam amazed how so manypeople have to "modernise" their car to make it reliable. 6v or 12v alts,converted starters,leakless WP,s,modern carbs & dists,rear main seals,etc etc.The original enginering was well thought out & very reliable when built to new car standards.
 
What do you have for battery ground?
What is the alternator for ground?

There's a good chance (like 100%) that you didn't match the battery ground to the alternator ground. Change your battery to the correct POSITIVE ground and try it again. Unfortunately you may have already cooked one or both of the alternators.

Once you have the correct battery ground, turn the lights on to see if the ammeter reads correctly. If it doesn't, then you need to switch the wires on the rear of the meter.
 
I knew an old man that instantly burned up two brand new 6 volt positive ground alternators. Boy did he cuss the vendor. Turned out the battery was installed as a negative ground. The negative ground wasn't a problem before with the generator as they are "polarized" when installed.
 
700rpm said:
"Since I will be driving the car I opted for an alternator. "

There is no reason you can't drive the car with a generator. Thousands of people do it. Look at the trouble you're having by trying to put something on the car that wasn't there originally. Keep it stock. It'll work fine and it's easier to fix when it doesn't.
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columbiA said:
A properly rebuilt generator will last 100,000 miles if you adjust the 3rd brush properly or use an electronic voltage reg.Iam amazed how so manypeople have to "modernise" their car to make it reliable. 6v or 12v alts,converted starters,leakless WP,s,modern carbs & dists,rear main seals,etc etc.The original enginering was well thought out & very reliable when built to new car standards.
Click to expand...

Richard Wilson said:
I knew an old man that instantly burned up two brand new 6 volt positive ground alternators. Boy did he cuss the vendor. Turned out the battery was installed as a negative ground. The negative ground wasn't a problem before with the generator as they are "polarized" when installed.
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Richard, I was not in any way "cussing out" Bert's. They are a valuable resource to me.
I was just stating my reasoning, since it is considered by some as blasphemy to use anything other than the original configuration.
I thought if it were recommended by Bert's, it's good enough for me. And it is.
 
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