Check your PM

 

Hello CO, Just an update before I put the car away for a couple weeks. The boat has been calling my name to go fishing and it's time. I spent some time yesterday talking with Stellar (Mark) from this site and we did some troubleshooting. Though we were able to stop the over charging issue with a regulator change. I also added a ground strap to the regulator going to the firewall were it meets the engine ground. Now bat voltage is at 12.5 at idle. Raise the rpm and the volts rise and come back down with rpm. Not over 14.5 volts. Something Stellar mentioned was that with the reg harness disconnected it would do the same thing. Could raising the rpm make the voltage go up with no regulator connected? Anyway I'll start fresh after a rest. Willing to listen to any "sounds crazy but" stories anyone has that may shine some light on my issue. Even if its not crazy. Big thanks to Mark for taking time out to assist. Greg

 

Don't see how a properly wired, properly working alternator could increase voltage with the regulator disconnected as the field isn't energized when the regulator is disconnected. If it did charge with the regulator disconnected I'd be looking for a short that is energizing the field.

Anyone agree, disagree?

 

There might exist possibility of a wiring issue, something placing large demand on ALT as RPM increases esp. if you witness this w/ the VR completely removed from the charging circuit. I would not expect ALT to increase voltage output as RPM increases without a VR esp. anything above 15VDC - that’s like a runaway train. It would be odd headlights would influence this behavior “if” wiring was correct, yet you did say you had/have a headlight issue. Any chance your headlights are very, very bright? You might try selectively pulling fuses one at a time and repeat your voltage readings each time to see if perhaps a particular circuit is involved? If you pull a fuse, increase RPM but voltage no longer goes up, up and up you may have isolated the offending circuit.

 

Sugar Bear I Agree!! X2. Thats what I told him in our conversation. He will be away from working on the car for a couple of weeks, so the answers will have to wait until then. (Overcharge possibilities- Battery, Ground, Alternator, Regulator, Wires.) He tried 2 batteries being known as good. Two regulators ,both still showing overcharge with lite on. I'm not sure when he replaced the wire harness for the charging circuit, but when doing tests I asked for, everything seemed to be good. I told him I suspected a bad new regulator. He replaced the new regulator with another new one. At this point the charging was within normal range, but the charge indicator lite was still on. I offered to send him one of my known good regulators and at this point I asked him to unplug the regulator and rev the engine. He said the volts increased with high RPM. I then asked him to test for continuity between the alternator plug wires with both the regulator plug and the alternator plug disconnected. He was too busy at the time and will follow up in a couple of weeks when he can get back at the problem. I guess it is possible for there to have been enough residual magnetism in the rotor to induce the stator windings and trigger a charge. Since he will not be running it for a couple of weeks it's possible the rotor magnetism will dissipate enough that it won't do the same when he returns. If there is no continuity between the F wire and the #2 (R) wire, I think he has been getting defective regulators, and a good one will solve the problem. Sugar Bear, or anyone else, give me your thoughts.

 

Does the alternator have a square plug or a rectangular one? Is the alternator an original type Delo? Someone please confirm but, my recollection is a '68 442 should have a square plug external regulator alternator. A '69 442 would be an internal rectangular plug alternator. I realize the OP's car has an external regulator but wondering if someone installed a different alternator.

 

10DN external with square plug.

 

I would start by replacing the battery cables. I see that you have used repair terminals, and they should only be a very temporary fix for replacing the cables with new. If you were to split the wiring jacket open, there is a very good chance that you will find a lot of corrosion under the plastic that can lead to your problems. As previously said, clean up your wiring issues and then do the testing. Electrical current is dependent of having clean tight connections. Let us know what you find under the battery cables plastic insulation with pictures.

 

It would be interesting to see the voltage at the battery with everything hooked up at a high idle and then with the regulator disconnected and then with the regulator disconnected and the alternator unplugged at the same time. If it stops charging with the alternator and the regulator unplugged the field wire is getting energized when it shouldn't be with the regulator unplugged. This certainly could be from what Junkman said about corrosion in the harness creating a short circuit OR something is wired improperly. This problem is interesting.

 

There's a theme here. Unlikely to suspect one size fits all resolution.

(1) (2) (3) (4) (5) (6) (7)

 

I'm (very) curious what this means & why it was done....

 

THAT is an interesting question. Did it get changed from rectangular to square or vice versa?

 

Post a picture of the ALT, wiring of the ALT & picture of the ALT plug.

 

Hello CO. As requested, pics of wiring and alt. I was referring my changing from using spade terminals and installed the correct plug. The car has always been exterior regulated. As for the headlights I have found the loose connection and they are working well now.

 

To bring all up to date, All of my playing around with the alt has led to a stripped thread so Im returning it to Napa. Ill post some video when the car is running again later today. Greg

 

Junkman, Thanks for your input. I have new battery cables coming with new harnesses. I did use new cable when I put those terminals on. As for cleaning up I have been busy. I was going to post a picture of the pile of wires removed but cant find it now. More to do though

 

Try this:

 

Turning into moot point now as the harness will be here early next week. I will find out why I was having this problem. Where I am now; Got the new alt from Napa and installed. I can no longer get the charge to climb as before. Regulator was new when I walked away 2 weeks ago. Still have the gen light and 12.5 VDC at the battery at idle. ran new field wires to bypass the harness. Same outcome. So, decided to do some cleanup on distribution /fuse block. It was missing a screw so replaced it and tightened it up last Monday but when I removed the fuse for Power relay, top left corner under flasher relay one of the connections is loose inside the panel. I only get 11.9 VDC there and the one below it. All others are 12.5 battery voltage My gut tells me this could be my issue. My question to all is: When the key is on, (not running) I get 12.5 volts at the regulator terminal 4. When the engine is running with reg plugged in it goes down to 3.5VDC. Is this normal? Should it be battery voltage? or perhaps 0? Thanks to all for your input. I bought this car as a way to learn without messing up something nicer. Guess I'm getting my money's worth. Greg