Hi all,

I just replaced the voltage regulator that I got from Ground Up Restorations in my 1970 Elky SS 396 and now the lights (headlights, interior lights, dash lights, etc.) are pulsating. What could the cause of this be? It did not appear to be doing this before the new voltage regulator was installed. I also had the alternator rebuilt prior to installing the new voltage regulator. Could the alternator be messed up also? It is charging at about 14.3 volts at the battery which seems to be a lot better than what the old voltage regulator was charging at (12.3 v) Any suggestions or help would greatly be appreciated.

Thanks,

Brian

Sounds like regulator. Try changing to a solid state regulator. AutoZone has the Wells part number VR715 for around $11.00.

Originally posted by John_Muha:
Sounds like regulator. Try changing to a solid state regulator. AutoZone has the Wells part number VR715 for around $11.00. John,

I need to keep this all original as I want it to be a concourse car. Thanks for the idea though.

Brian

Well, it still sounds like the regulator you installed is causing the pulsing. For $11.00 one could isolate the problem.
I installed a NOS Delco into my 72 when the original finally died after 30 years. The 64 has the Wells. Either work just as well as the other.

I just ran the elky with the head lights on and all of the accessories going for about a minute or two. I then shut all of the forementioned things off and let the battery charge back up then repeated it again. The lights seem to pulsate now but not as strong as before. Could this pulsating because by a low battery? This battery in the car was not on a trickle charger and the vehicle is in an unheated garage (one of those cover-it garages).

Brian. Just a thought. Could it be the pulsating is caused by the circuit breaker in the headlight switch? That would imply a rather slow pusle though. This would mean the load is too high; perhaps wires were mixed up?

Rob

Rusty66,

The wires going into the voltage regulator are in the 4 wire plug which were not removed from the plastic plug head. The wires on the back of the alternator can only go in one way due to the way the plug goes in and there is only one other wire which gets attached to the stud on the back of the alternator. I dont think it could be the headlight switch as it did not do this before. I am kinda leaning toward the fact that the battery was not at full charge when I started the car cause it cranked over kinda slow but fired up. As the car ran longer, the pulsating seemed to not be as strong and as fast. I will keep everyone posted as to what happens.

As John has stated, this "pulsing" is caused by the cycling of the mechanical regulator contacts. If you measure the voltage across the battery terminals with a VOM, you can see the pulsation. I changed over to the Wells unit about 3 years and 80,000 miles ago and have had no problem since. It fits in the original "footprint" of the original AND the cover from the Delco will fit the Wells unit. Just be sure that the mounting base is grounded to the radiator support. You'll have to decide whether to stay original or put up with the pulsating lights. ;)

Brian,i would send the regulator back as defective if you really think it bad which it could be with the symptoms yoy have.

But i had pulsating headlights on both my 96 Iroc & 88 Monte ss and had both alt's rblt at a reputable rebuilder in the area and he said it was not the interanl regulators that were bad in my alts making the light pulsate,it believe he said it was the rectifier in both cases.

So if you replace the regulator a 2nd time and it still has the pulsating lights then have the alt checkd out again because that's what it was in both of my cases.

Scott

Everything on the elky is stock so no lobing of a cam and idle is set to factory specs. The voltage regulator seems to be charing with the lights off at 14.2 / 14.3 and with the lights on charging at 14.6 / 14.8 volts. I tried running a jumper wire from the voltage regulator metal base to the neg. side of the battery and no change so I doubt it is a ground problem. The old voltage regulator was bad and was overcharging to the point of high 15's to low 16 volts just at idle. This is why I replaced it and had the alternator rebuilt. Battery charged up with engine off was reading 12.9 volts on a 6 mos old battery. Battery charger was on the battery for only about maybe 3 or 4 hrs.

It seems that the higher the voltage, the worse the pulsating is with the lights. Could too much of a charge cause the lights to pulsate?

Ok,

Good news! ! ! After calling Ground Up Restorations, they advised me to send the old one back and to get another one from a local parts store to see if it would change the problem. They also mentioned about finding an original one at a junk yard. I ended up going to the junk yard and found an original Delco-Remy voltage regulator. Actually I found two that had the staggered lettering of Delco-Remy so I got both of them for $20. Brought them home to try them out and both worked perfectly. The lights no longer pulsate and I have two original regulators. One was charging a little higher than the other at about mid 14's and the other was in the mid to low 14s with the lights off. With all of the accessories on, it was reading about 12.3/12.2 volts. The highest the reading was at the low 15s when I turned everything off and it went up that high. After a little while, it jumped down to 14 volts. I assume that it read that the battery was fully charged at that point. Anyway, even though the old regulator was charging at the right voltage, it appears to be the problem with the pulsating.

I will let everyone know how this turns out.

Thanks for everyones input,

Brian

It sounds like you fixed it. I was wondering about if it did it when the engine was OFF? It could have been a loose (poor) ground.

Voltage is too low when everything is on.

John,

This is with everything on going full blast (radio, blower motor, headlights, and air). My other car (71 Buick Skylark GS 350) idles about the same with everything on that also. I also tried to get the Wells voltage regulator at Auto Zone and Strauss Discount Auto. Both places said the VR715 has been discontinued. graemlins/angry.gif Oh well, the lights are not pulsating anymore and the voltage seems to be working normal again. Hopefully the problem has been taken care of and now I can move onto something else.