Mach 1 Club

Full Version: new autolite volt reg keeps alt light on
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Pages: 1 2
I decided to replace my voltage regulator for no other reason than putting on concours correct autolite one on my 69 mach 1.  When I do, the alternator light stays on when i start the car.  if i put the old one back in, alternator light goes off after start.  wiring connector has orange wire on the right contact in the diagram which only fits one way.  need some advise on why i'm having issue with autolite VR - thanks rob
With the thought of it being new, and it should be a good one. Have you put a volt meter across the battery to see if it's actually charging? It is entirely possible that the new regulator has stuck open from sitting for 30 years, or is just plain faulty. You should see 13 plus volts with the engine running somewhere around 1500 rpm. The figures won't be exact but if you only got 12.2 or 12.3 it's not charging for sure. Hope it helps. 

JTS
(07-14-2019, 11:06 AM)JTS71 Mach1 Wrote: [ -> ]With the thought of it being new, and it should be a good one. Have you put a volt meter across the battery to see if it's actually charging? It is entirely possible that the new regulator has stuck open from sitting for 30 years, or is just plain faulty. You should see 13 plus volts with the engine running somewhere around 1500 rpm. The figures won't be exact but if you only got 12.2 or 12.3 it's not charging for sure. Hope it helps. 

JTS

I have a voltmeter gauge and it reads around 12.2. As soon as I put the old one back in I get close to 14v.  Is there a way to unstuck it? I bought it at cjpony.
Slap it around a couple times. I know that sounds silly but. Cover something solid, with towels, or something to protect the case from damage, scuffs, scrapes, or dents, and bounce it off the surface several times. If that doesn't do it. With the engine running take a rubber mallet, and tap all around it several times, again being careful not to dent it. If that doesn't wake it up, send it back. Cause it's dead. Hope it helps. 

JTS
My first guess would be something is wrong with the new regulator.  I'd also check the voltage output from the stator terminal on the alternator and the where it connects to the voltage regulator.  Stator terminal voltage should be at least half of the charging system voltage.  As you can see, the stator voltage from the alternator closes contacts inside the voltage regulator allowing battery voltage tp pass through terminal "A" on the voltage regulator and back-feed the charge indicator light.  Thus the end result is equal voltage on both sides of the light, which stops current flow through the light, and turns it off.

After reading your other posts, the charging system is not working.  If it works fine with the old regulator, send it back or swap the covers if you want that original look.  I hate to say this, but OEM reproduction parts look nice and original correct, but are often poor quality.  I too like the original look, but if that means using reproduction parts, no thank you.



[Image: 1850406811_1969MustangAlternatorWiringWi...ceedea.jpg]
I tapped it a few times and still didn't work. I called for replacement. I'll keep you guys posted. thanks rob
Yeah I'd say that's the best idea. Then you won't have to worry about it. Good Luck.

JTS
I got the replacement VR but same issue.  Now I am really puzzled. I may have to listen to the old expression, "if it aint broke dont fix it". Here is a picture of the VR pigtail. Does anyone know what the extra splice yellow wire is for? It is not connected to anything
I think that pigtail is for a radio noise suppressor.

Since you have an alternator light, I am assuming you have a factory tachometer instrument panel.  Just to verify, do you have the correct wiring harness for the alternator?  There are two alternator harnesses, one for a factory tachometer instrument panel and one without a factory tachometer.  The one for a factory tachometer has the additional wire going to the STA (stator) terminal on the alternator.

If the above is correct, it might be worth having the alternator checked to be certain it is working okay.  I don't know why it wouldn't be.  But, since one regulator is old school with mechanical relays, springs, and contacts and the other is electronic, something might be going on with the alternator.  I know that doesn't make much sense but this is your second regulator.  Plus, an alternator can have, for example, a shorted diode in the rectifier and still work okay but not as good as it should.

Is the alternator now charging with the new regulator even though the alt light is still on?  If so, definitely check the voltage at the "S" terminal on the voltage regulator with the engine running.  That should be approx. half the charging system voltage to shut off the light.

Let us know what you find.
I have a tach car and the alternator wiring harness is for tach car. The battery doesn't charge with new mechanical VR but does with electronic one. I called up CJP and they are looking into it for me.
Pages: 1 2