3 blown regulators

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Snippy55

Guest
Looking for help. I recently had a lot of work to my 1968 Dart done 2 months ago (engine rebuild, new tranny, alumminum rad with twin cooling fans, higher output alternator) The motor is a 360. The ignition system is MSG.

Since the rebuild, the car has blown 3 regulators..I am assuming that this has something to do with the twin electric cooling fans that were added or maybe the higher output alternator.

Does anybody have any suggestions or comments on what may be the cause/fix?

Thanks in advance.:newb:
 
More load on the system should not cause regulator problems. You might have WIRING failures, or ALTERNATOR failures, but it should not affect the regulator

Where/ what brand are you buying?

The 69/ earlier regulator seems to have become a "third world" item, difficult to find good quality nowadays.

I did upgrade mine to the 70/ later style, mostly because I had a couple of spares of that type and happened to have a late alternator.
 
Thanks for the feedback. No I have not upgrade to a solid-state unit..is this something that you would recommend?
 
The last two were Standard Auotparts units, the first one was the original I beleieve.
They seem to last a couple of weeks and then die...I am not sure if coincidence but all failures have occured at night when lights are on...this is why I think it maybe too much current?
 
System current does not affect regulators on an alternator.

Pop one of the covers off one of the failed units. Are they solid state inside, or look like a relay?

Is it possible you are not getting them mounted solid and they are vibrating badly?

It might also be that the alternator FIELD has a partial short, just enough to cause too much field current. This might be killing the regulators
 
Set your DMM to 'Amps', and full field the alternator through it. The engine does not even need to be running for this test.

Many newer alternators can draw as much as 10 amps through the rotor coil. Depending on your 'high output' alternator, it may simply be too much for the old style regulator.

Check the rotor current & post it.

B.
 
Thanks all for your help. I tested the alternator and it checked out okay...it turns out that the regulator was not fatened securley to the firewall...:-(
Anyways, it looks like the issue is fixed...tahnsk again!!


bohica2xo said:
Set your DMM to 'Amps', and full field the alternator through it. The engine does not even need to be running for this test.

Many newer alternators can draw as much as 10 amps through the rotor coil. Depending on your 'high output' alternator, it may simply be too much for the old style regulator.

Check the rotor current & post it.

B.
Click to expand...
 
Thanks all for your help. I tested the alternator and it checked out okay...it turns out that the regulator was not fastened securley to the firewall...:-(
Anyways, it looks like the issue is fixed...thanks again!!
 
On my wifes 79 Lil Red Express we had the same thing happening. On her truck the wiper motor was dead shorted and the switch was in the on position. You could not really tell by looking the switch was on because how how they are made. She never drove it in the rain, so never looked for that to be the problem, just started tracing with short finder and found it. Replaced the wiper motor and all was well. There was no fuse in the wiring for the wiper motor so it did on blow a fuse as one would expect.

Not much difference in most A bodies wiring and that of the Little Red, so a short or intermitent short could cause the problem.
 
Snippy55 said:
Looking for help. I recently had a lot of work to my 1968 Dart done 2 months ago (engine rebuild, new tranny, alumminum rad with twin cooling fans, higher output alternator) The motor is a 360. The ignition system is MSG.

Since the rebuild, the car has blown 3 regulators..I am assuming that this has something to do with the twin electric cooling fans that were added or maybe the higher output alternator.

Does anybody have any suggestions or comments on what may be the cause/fix?

Thanks in advance.:newb:
Click to expand...

Update..further issue...I replaced the older style regulator with a Mopar electronic unit...here is my new issue (or maybe the cause of previous issue)...the Voltmeter in car sits at approx. 16V and you can see it bouncing of flicking (not steady) at 16V...if I turn on the lights it stops bouncing...the Ammeter on the other hand bounces wildly without the lights on but goes to full charge when lights are turned on.

to me, the voltmeter should be just under 14V and the ammeter should not be bouncing crazily.
I am confused...can anyone shed some light on what might be going on?

I don't want to cook the battery or wiring etc..
 
When you did the engine swap , did the ground strap between firewall and engine block get reattached ?
 
Snippy55 said:
Update..further issue...I replaced the older style regulator with a Mopar electronic unit...here is my new issue (or maybe the cause of previous issue)...the Voltmeter in car sits at approx. 16V and you can see it bouncing of flicking (not steady) at 16V....
Click to expand...

I want you to explain to me how you did this change......

Are you saying you went to the 70/ later alternator and regulator?

Or did you buy an electronic replacement for the 69/ earlier regulator?

You need to check the ground side of the circuit, and the hot side of the circuit

Do the following:

Get the battery "up" IE "normal" with the engine running, all accessories off, and RPM to simulate low to medium cruise

Take your meter on low volts, stab one probe directly onto the battery neg. post, and the other directly onto the regulator frame. Make sure you penetrate the chrome/ paint.

You are looking for a very low reading. Zero is perfect, anything over .2V (two tenths of a volt) is too high, and shows you have a ground problem

Now check the "hot" side of the circuit.

Once again, engine to simulate "medium cruise" stab one probe directly onto the batter positive post, and the other probe either on the regulator IGN terminal, or the IGN terminal of the ballast resistor. This is the traditional "dark blue" supplying "ignition run" from the ignition switch

Once again, you are looking for a low reading, and over .2V indicates a drop in the harness

A double check on this same current path, is to turn the engine off, turn the key to "run." Make the same check as before, one probe on battery, one probe on IGN terminal of regulator. Note the reading.

The probable drops in the harness path, are from the battery, through the fuse link, through the BULKHEAD CONNECTOR, the ammeter and it's circuit, the Ignition switch connector and through the switch, and back out the switch connector, and back out the BULKHEAD CONNECTOR
 
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