I am still having the voltage flicker and over charge situation with the '72 442.

The Service manual shows two wires from the negative terminal of the battery. One goes to the engine and one to the chassis. Also, the ground braid from the firewall (located at the external voltage regulator) goes to the engine.

My questions are as follows:
1. Is there a second wire off of the negative terminal or is the ground strap for the chassis somewhere else, and
2. Are there any more ground straps other than those shown on the electrical diagram in the Service Manual?

It appears from the posts I have read that the horn relay can have an affect on this situation as well.

Any information would be appreciated so I can get the grounds correct before I tackle adjusting the voltage regulator.

 

Success!!

Found 2nd wire off of negative terminal Lossened and reconnected. I guess I am blind, but as many times as I have been under the hood I had never seen the small wire going to the radiator support bracket.

Reconnected both battery and body strap at voltage regulator.

Voltage out of regulator running high (15.1 volts). So will get a good mercury thermometer and will adjust the voltage regulator per the manual.

 

Glad you found the problem...
Even after proper adjustment, you might still see a slight flickering of the lights. My car used to do that after starting and I even heard the clicking sounds of the regulator contacts.
I replaced the mechanical reg with an identical looking electronic unit and both issues went away. Just an option if the flickering persists.

 

thanks Rob, I will look into that.

 

Well, the Voltage Regulator bought from Year one does not have an adjustment screw. The only way to adjust the voltage output is to change the tension of the regulator coil. By increaseing tension you increase voltage and by decreasing tension you decrease voltage. Since this was such a tedious and uncalibrated way of changing the voltage, I continued to look for a solid state voltage regulator. The out put voltage on the coil based voltage regulator was putting out about 15.3 voltage and chattering. The high voltage was causing the overcharge and there was no plastic adjustment as explained in the service manual for decreasing the loaded to unloaded voltage. The difference was about 0.5 volts which was causing the chatter and flicker in the lights.

I finally found a solid state regulator at Advance Auto (the regulator form NAPA was coil based as was the one from Yearone). I bought the Advance VR for $16,95 and then removed the made in China cover and replaced it with the Delco Remy cover which retains the original look.

I had previously cleaned all of the ground connections without correcting the problem. PROBLEM SOLVED there is no flicker and the voltage output is 14.6 exactly midrange of the recommended output from the Service Manual with a 0.2 load to unload change in voltage.

Thanks for all of the input and the continued suggestion to find a Solid State VR.

I would strongly suggest this as an upgrade to any Cutlass. The 69 -71 442's have a solid state internal VR on the alternator. However, in '72 the fact that the 442 became and option for the Cutlass and not it's own model, GM used the exteranl Cutlass VR on all '72 442's.

 

Sam, got your PM.
Glad you found one an that it fixed the problem.
Please post a picture of the original delco cover - have never seen an original!

 

Rob,

It looks just like yours from China except on the front It has embossed into the cover Delco Remy and under that it says Made in USA.

 

Cool - maybe I can find an old one at a bone yard, just to have that cover to swap with mine...

 

I went thru this same situation some 17 years ago. Nothing eliminated the flickering until I went with a 1 wire alt. No problems since.

 

Thanks, going to a one wire, which has a solid state internal VR, has been suggested as well , but that changes the stock from factory situation I am trying to maintain.

The solution of the solid state VR with an original cover maintains the stock appearance and provides the same functionality as a one wire interanl solid state VR.

I agree that the coil based VR without the factory adjustment capability (screw to adjust tension on the primary coil and the plastic **** to adjust load/unload voltage) would probably never solve the flicker and over/under charge situations I have heard so much about and experienced myself. This was obviously a problem bqack in '72 because of the detail on the problem in the Service manual.

If the owner is not interested in stock original appearance th one wire alternator is a superior fix. However, if the stock appearance is a concern the solid state regulator in the the old can is appropriate.

 

I think I have a Delco Voltage Regulator for a 72 model. The one I have is a D635 (1119515). Does that sound right?

 

I will look at mine tomorrow and let you know.

 

Where did you find the solid state regulator? roughly how much was it? My lights have been flickering lately. I checked the voltage on the battery with a dmm, it ranges from 11.5 volts with all accessories on to about 14 with everything off and the engine revving. I've checked the unit, there is a grounding strap that is connected to the back of the motor.

 

I got mine from a mom n pop auto electrical shop way out in the boonies during a vacation drive. Cannot even remember the name of the place...
It was about 15 bucks cash n carry.
11.5 at full load is low. Either the reg is going south or the alt popped a diode...
This is assuming you had all STOCK options turned on - no engine fans, seat heaters, etc.

 

Advance Auto has the electronic Voltage regulators. I hope this solves your problem. You may want to recheck all the ground connections since they come loose or get corroded.

 

For any of you who want ORIGINAL ++ DELCO ++ VOLTAGE REGULATORS ----- they are N.O.S. -- so they are not solid state --- and many people on this planet prefer them --- call me, I have plenty,

CRAIG -- 516 - 485 - 1935 ... New York......

 

I got mine here

http://www.qualitypowerauto.com/catalog.php?item=140

No flickering, rock solid at 14.6