You can download the AIM

 

Thank you. I have the AIM but am told the separate (printed) wiring diagrams are much more user-friendly. I may find out differently, though, once they arrive.

 

Possibly a poor battery connection. Under heavy electrical loads a poor connection become more resistive causing the voltage regulator to output a higher voltage which in turn can cause the GEN light to be lit.

So clean the battery posts as well as the other end of the battery cables. Also make sure the generator and voltage regulator are also getting a good ground through their brackets. If that doesn't work I would replace the voltage regulator.

 

Thanks for these suggestions. I have seen weak battery situations in the past that caused erratic charging behavior -- and in this case I'm not a fan of the spring-loaded connector on the positive cable on this car. (Interesting the regular type connector is on the negative.) There's not one speck of corrosion on these connectors, as they've been kept perfect - but that doesn't mean all the connections are as tight as they should be. The original style VR is still in place, so that may indeed warrant replacing.

 

OP

Assuming your battery, battery cables/connections are good, I suspect the voltage regulator is the problem. I installed a solid state one made by Tuff Stuff which stabilized my voltage

With that said you may have fatigued wire or ground somewhere draining current.

Also I found adding headlight relays, which takes that load off the headlight switch, made all my interior, headlight & tail lights brighter. I bought the headlight relay kit at Speedway. Plug & play, not cutting any wires

 

The headlight relay is new to me, so I'll consider it after a few other things are straightened up. I did replace the headlight switch in 1973 after it went open on me one night and had to drive many miles on the Interstate with parking lights. After checking the battery under load, and checking all connections, I'll go after the VR if things are still wonky with the GEN light.

Mine was originally DWB with the off-white vinyl top but was restored to Marina Blue before I repurchased it. I wish they'd stayed with DWB. Was your pic taken at the beachside park in Goleta - or pretty nearby? 805 is one of our favorite areas to visit even though it's 2,000 miles away.

 

I don't think the wiring diagram will be of much help troubleshooting your issue. What I think might help more would be the 1967 Chassis Service Manual. In it is a section on Engine Electrical Charging System. In it are testing procedures to track the issue(s) down. You can be a parts swapper if you want.

I know on my 68 Chevy II Nova's charging system someone had gone inside the original voltage regulator and "adjusted" it only to have very nice and bright headlights but I don't think they checked their work as when I got it I measured the voltage at the battery and it was over 16V. Yep it made the headlights brighter but also made the bulbs burn out quicker on the car. Also too some of the original voltage regulators used contact points which can present issues from age and arcing.

I used the 68 Chassis Service Manual for my car and then was able to readjust the original voltage regulator to where it is working just fine. I also bought another original style as a backup for that just in case scenario. Some have put on the old original regulator tops onto the newer solid state bases but one can still see that it is not an original setup any longer.

In another reply you said the one battery has a regular type connector ?. Is it a decent one or one of the 99 cent ones that clamp onto bare wire ?.

Jim

 

My regular type battery connector is not a decent one. It is one of the "round clamp onto bare wire" connectors that can't be worked on or tightened (even though it has the nut to tighten onto the battery post). I'll replace both as a matter of good practice even if they're not causing the problem. I know my VR is doing something since I can see the voltage rise while charging and then drop back - but it certainly might not be acting right. Thanks for the suggestions!

 

Here's link to download the AIM and other manuals. They're extremely helpful.

Downloadable AIM's and some service manuals

Downloadable AIM's and some service manuals

www.camaros.org

 

Check with Larry DuBois (69-er on here) and see if you can buy a set of his PDFs. Very comprehensive with troubleshooting tips. Full color wiring diagrams that are well labeled, definitely worth the $15-$20 or whatever Larry charged... I think its about 30 pages. It is 1969 specific, but I'm sure most of it is relevant to 67-68 as well. I liked them so much I printed them, then ran them thru my spiral binder, made nice book out of them. Made a cover and laminated cover and back to give it some body. Forgive the smudges on the cover LOL.

Mike

 

Allan - Thanks for the download links! I didn't have all of these.
57 - I'll see what the printed wiring pdfs look like that arrive, and may indeed go after these from Larry if they aren't of sufficient quality.

 

I would look into your VR. If your not familiar with the original voltage regulators and how to work them them, a solid state upgrade will be your best bet. Go to any auto parts store and ask for a VR715. The attached article may help explain.

 

Check connections especially grounds first but sounds like a bad diode to me.

 

I've read through the detailed testing process in the manual and am leaning toward going ahead with a new VR. The VR715 has limited availability nowadays and the price has gone up quite a bit. The Tuff Stuff VRs are more reasonably priced and I'm curious if they're of decent quality.

rp- when I see the 15VDC during high charge it makes me think the diodes are OK, but the ALT is still a possible problem here.

Thanks all for the suggestions/advice.

 

The voltage can be ok and still have one or more bad diodes. An alternator output test would tell.

 

Drove to my local Autozone and put the tester on it: Battery great but VR and Diodes Fail. I'll go for the VR first since that could cause the ALT test to fail -- but could indeed end up with a bad diode.

 

Auto Zone would have tested the alternator by itself. It's either good or bad. You don't have an internally regulated alternator do you? Your last post is confusing.

 

My VR is external. AutoZone did all the tests at the battery and their screen said the battery was at 100%, but then it said the VR Failed the test and the Diodes Failed the test. While it is possible both the VR and ALT are bad, I'd like to think that is unlikely. Is it possible one of the two being defective would result in a Failed test on both?

 

Ok, so it sounds like they tested everything on the car. The alternator should be tested off the car on a machine. Then there is no doubts. The battery should be tested off the car with a load tester also.

 

Yeah, ideally these are tested alone rather than in the system where things can interact. Not so concerned about the batter being tested in the car if everything is shut down and they do a real load test - but the other stuff definitely interacts and can affect one way or the other.

 

How much does a VR cost would n't it be worth it to just try it and see what happens then if it doesn't fix anything you can test your alternator or look for a loose ground. I remember someone telling me that your alternator only works over 1000 rpm.

 

As SOA stated above, I can be a parts swapper, or I can run some tests to try and see what's really wrong. I didn't run all the tests in the Manual but I did enough to see I've either got a bad VR or a bad ALT (diode) - or both. I'm awaiting the arrival of the new Tuff Stuff VR, and will soon know if that fixes the problem.

 

To close this out, the Tuff Stuff VR resolved this problem (although another unrelated problem appeared at the time it was installed).