Over charge mystery 69 cuda

[jim in seattle]

69 barracuda. Yes I have read all the threads I can find on here. I have about 50 hours into this one and am at the end of my patience! Here is what I know:

charges at 16V+ at idle

new alternator (schucks), battery, regulator (napa), battery cables.

cleaned all rust /paint at battery ground to engine, regulator to chassis.

also have tried grounding alternator and regulator directly to battery, and chassis to battery direct ground

keeping mulitmeter neg at battery ground, I find high voltage (16+) while iding at:
-input to regulator
-alternator (dark blue wire that is activated by key)
-battery positive

I also get same readings using the alternator casing and regulator casing as the ground for these checks.

wtf?

 

[caferacerx]

is it staying at 16 volts when you increase the engine R.P.M. ?
if it is staying at 16 volts it is probably a defective voltage regulator
or one that was not properly calibrated

 

[jim in seattle]

is it staying at 16 volts when you increase the engine R.P.M. ?
if it is staying at 16 volts it is probably a defective voltage regulator
or one that was not properly calibrated

I can get it to 17V, and it has been as low as 15.5. 16V is the most common at idle.

Also, since original post, I put old alternator back on that schucks told me was tested dead (love those guys). same thing. The old alternator is a 3 field and the new one is a 2 field. The old one will not work until one of the fields is ground to negative at battery, but still charges 16v-ish

 

[67Dart273]

Make sure your meter is not at fault

Could be defective regulator

some claim the battery can cause this, I donoo

BUT have you checked the supply voltage AT THE REGULATOR ignition terminal?

Put your meter as close to the regulator (clean the connector!!) as possible on the ignition terminal, the other meter terminal directly on the battery positive. You want as low as reading as possible, zero is perfect. More than about .2 (two tenths) of a volt is too much, and indicates drop in the harness/ bulkhead connector/ ignition switch and related connectors.

(Alternately "rig" a jumper wire about no14, a good connection from battery positive directly to ign terminal of regulator, see if it drops the charging voltage)

 

[yellow68runner]

a poor BODY ground will cause this also

 

[caferacerx]

the alternator will put out higher voltage the faster it spins, it is the voltage regulator's job to regulate the voltage within set limits, usually 13 - 14.5 volts, it sounds like your voltage regulator is working but is calibrated for 15.5 - 17 volts, I would try replacing it, that should solve your problem, hopefully

 

[nothingbutdarts]

Also, since original post, I put old alternator back on. The old alternator is a 3 field and the new one is a 2 field. The old one will not work until one of the fields is ground to negative at battery

I must ask what type of voltage regulator you are running, is it the old style mechanical or was it converted to a new style Chrysler electronic regulator?

Chrysler never used a "3" field terminal alternator??? That I know of. Pictures of alt., regulator and wiring???????


As mentioned above; GROUND! and then GROUND.

 

[jim in seattle]

a poor BODY ground will cause this also

-I have run a 12g wire from the battery ground directly to 1) the alternator casing and 2) to where the regulator mounts to the chassis, both as temporary measures, to see if it made a difference. It did not.

-I have also verified that the cable from battery ground to engine is in good shape and has clean connections. Is there something else I should look at?

 

[nothingbutdarts]

I must ask what type of voltage regulator you are running, is it the old style mechanical or was it converted to a new style Chrysler electronic regulator?

Chrysler never used a "3" field terminal alternator??? That I know of. Pictures of alt., regulator and wiring???????


As mentioned above; GROUND! and then GROUND.

Did you read this????????

 

[jim in seattle]

Did you read this????????

yes- Thank You. I have to get back to my shop before I can take pics...

as far as the alternator- Iobought it like that. (3 field). both new and old do the same thing so i figure that isn't the issue. I don't know the brand of the regulator other than I bought one at Schucks that worked for about 10 minutes before my wiring fell apart (separate thread) and then this one from NAPA. It will be Monday evening before I get back there and get model numbers and pics...

 

[nothingbutdarts]

yes- Thank You. I have to get back to my shop before I can take pics...

as far as the alternator- Iobought it like that. (3 field). both new and old do the same thing so i figure that isn't the issue. I don't know the brand of the regulator other than I bought one at Schucks that worked for about 10 minutes before my wiring fell apart (separate thread) and then this one from NAPA. It will be Monday evening before I get back there and get model numbers and pics...

OK, has the wiring been converted from 1969 or are you still running the 1969 style regultor?

Also, have you had the battery tested?

I await pictures and more info.

 

[moparchuck67]

A low battery in your test/ohm meter will give a high voltage reading.

 

[jim in seattle]

I replaced the voltage regulator again and it all works. So I had TWO regulators that did not work when new. I guess that just means- for others reading this that may be trying to diagnose a problem with similar symptoms- that you cannot rule out a part just because it is new.

 

[67Dart273]

I replaced the voltage regulator again and it all works. So I had TWO regulators that did not work when new. I guess that just means- for others reading this that may be trying to diagnose a problem with similar symtoms- that you cannot rule out a part just because it is new.

Jim, I've said that and said that and SAID that. Even then, I've got caught a time or two with a new defective part.

MAN always glad to hear a successful outcome!!

 

[caferacerx]

must have been a bad batch of parts, so much for quality control