Hello all,

I tested my voltage at the battery after a long drive and I have 12.3 volts. I know this is low. I then checked voltage at the generator with the car running, and I get about 14 volts. What could be going on here? My voltage regulator is about 2 monhts old, and I did polarize it, unless I did that part wrong. Any ideas here? Battery is 1 year old. 1961 Olds 98, 394, 4bbl.

Thanks guys.

 

What is the voltage at the battery with the engine running?

 

It is about 12.1 - 12.3 with the engine running, no matter the idle.

 

I thought your issue was resolved a couple months ago? Something change? I recall you had a wire incorrectly installed. I'll have to look at your old thread when I get a chance.

 

I thought the same thing. The GEN light issue was taken care of. Voltage was around 14.5 or so running, and since then, it has dropped. I have changed nothing since.

 

Here's your old thread just for context in case another member wants to review. I'll look at it in a bit. It still may be related to your current (new) issue.

GEN light always on?

 

Just for clarity, not to be picky; but, you don't polarize a VR, you polarize the ALT via the VR on your GM vehicle.

 

I do appreciate the nit pick, I gotta get this stuff right.

 

That's OK. Not everyone is going to get that point. The point being is the ALT needs to know which direction to send the voltage. You're fine, you're getting it.

 

Mike - I spent time reviewing your other thread w/ particular attention to two items:

(1) You noted previous mechanics mentioned some wiring issues/peculiarities (near the fuse box/firewall?); and,
(2) Wiring diagrams.

If this were my issue, I would unequivocally start w/ the absolute basics by labeling every single wire which makes up the charging circuit. Between your B&W diagram(s) and the diagrams supplied by Supernice88 you should take a marker/pen and painters (blue) tape and label each wire in the wiring circuit so each wire clearly represents, is identifiable & most importantly matches the exact wiring of the wiring diagrams. Yes, this can be daunting - we've all had to do it at some point. There exists no miracle cure here. You must label & identify every wire in the charging circuit. There are a cluster of red wires you'll find in the color wiring diagram - label every one of them to match the wiring diagram. Stay with the charging circuit only. Label the battery wire(s), the horn relay junction block wires, every wire between the generator & the VR. This is going to take you a little time & effort. Lay out ~5" pieces of blue painter's tape on a table. Write on each piece of tape the color & purpose of wire TO/FROM VR>BATT, TO/FROM VR FIELD, TO/FROM horn relay junction box, etc. etc. etc. Use a notebook (whatever), print out the wiring diagrams. I see no other manner in which to begin troubleshooting your issue until you have 100% confidence your labels match the wiring diagrams/schematics.

EDIT: Don't short cut yourself. You MUST validate the beginning and end-point of each of those wires -don't simply toss on a label and call it a day. VALIDATE each wire's beginning and end point match the wiring diagram. Good Luck and have fun.

 

Take a volt reading at the reg gen terminal with the car at idle, then again with the engine at a higher rpm. Do the same reading at the reg B terminal

 

Thanks for that, I will do that. I appreciate the feedback as always.

 

If you can't figure out (read) where a particular wire should begin &/or end (e.g. appears confusing) just ask we'll help figure it out. No sense guessing since you want it iron clad.

 

I haven’t tacked the wire by wire yet. I’m just perplexed that the voltage dropped out of the clear blue. One day it was running at 14.2 or so, engine running. No drop in voltage. The next day, it wouldn’t push over 12.4, approximately. Could the VR be bad? It’s newer, for sure within a year at the most. Is it worth replacing the VR and polarizing the GEN again with a new VR?

 

I'd first check the wiring, but I'm going to guess the VR is bad.

 

You replaced what - about three VRs before you created the 1st thread when we resolved the Brown wire which was supposed to go the VR was instead connected to the front fire wall by a PO. When we got the Brown wire figured out the GEN light worked properly. Yet, I did have some suspicions other wiring might be suspicious. And, in particular you heard from other mechanics who were working on your car suggest there was something a muck w/ the wiring near the fuse box (passenger compartment side) on the fire wall.

My suspicions remain I think you have some faulty wiring - just my gut feeling. I wouldn't advise you to replace the VR (what the fourth time?) until you validate the electrical charging circuit matches the wiring diagram. This will take some time, but you've plenty of members here always willing to lend a hand. Personally, I like to see wiring which is nice & tidy and matches the OEM wiring schematic as the jumping off place.

 

I mean certainly, let's just face facts here. Whomever connected/fastened (screwed) the Brown wire from the GEN light to the screw on the body panel of the car instead of the VR definitely wasn't following a wiring diagram.

 

Check/compare the voltage output on a fully charged battery and at the same RPM each time. Generators unlike alternators produce very little at idle. The symptoms do sound like a VR problem but diagnose it to learn, save money and preserve original parts.

 

Valid points pertaining to voltage output regarding a GEN vs. an ALT.

I mean, it isn't going to cost you a dime (not even a penny) if you think you may not have polarized the GEN correctly via the VR. I mean, hell, you might try to polarize the GEN (via the VR) again in case you think you may not have done it correctly.

 

^^^^^^^ This.

 

Yes this would be the 4th VR replaced. I will check the wiring diagram tomorrow, and unwrap my wires from GEN to VR. I’ll start fresh, like you said Norm.

Would a bad VR have any signs it’s bad? Burns, etc.?

 

Honestly, I believe a solid representation your wiring matches the OEM wiring diagram is the starting point for this car now and moving forward so you have iron clad knowledge when you tackle any other wiring issues you have confidence the wiring is correct. However, with that said, as I indicated in the other 4GC thread, we're waiting on input from you on the suggestion by Stellar and re-stated by Charlie:

 

Noted. This will be my first test tomorrow when I get back at it.

 

Update: tested the voltage at the battery first, at idle. It hovers around 12.8V. Then I tested at BATT terminal on VR, same. Then I tested Terminal B (armature), and got the same readings.

I then increased the idle, and tested at the battery, BATT terminal of VR, and armature terminal of VR and the voltage increased with engine RPMs. Highest noted voltage was 14.5.

GEN light still on, dimly, but it’s on. Thoughts off the bat?

 

Mike - I know we tested this previously in your other thread when the light remained on continuously; however, I believe there's an opportunity to evaluate this test once again.

Is the gen light on when the key is in the run position and engine is not running?

Additionally, can you see if the GEN lamp decreases in brightness as RPM increases and increases in brightness as RPM decreases?

 

Norm, Is there a diode in the light circuit? If yes it could be leaking.

 

Jeff - I'm going to say no because I believe the vehicle has a D.C. Generator. If the dense matter between my ears is correct there would be no requirement for diodes. I think a D.C. Generator uses a split-ring commutator while an A.C. Generator uses slip-ring commutator. A split-ring commutator produces current in one direction (uni-direction e.g. D.C.) while a slip-ring commutator produces current in both directions (e.g. A.C.) alternating directions for every 1/2 turn about the coil. Diodes should only be required in an A.C. Generator to trap/conduct current so it flows in only one direction (uni-direction e.g. D.C.). Albeit, no diodes are required I don't believe.

 

I will let you know that tomorrow, I blew a 9amp fuse, which is responsible for back up lights, fuel gauge, and GEN and OIL lights. I have more coming tomorrow so I’ll be able to test and get you the info.

 

Obviously, you have an electrical issue somewhere. You only blow a fuse when an electrical issue/problem has developed. Has this happened previously in the time you've had the car? Is this a one-off because you were noodling about w/ wiring? The blown fuse issue needs resolution. You ran the car for ~3 years w/ the GEN lamp Brown wire hooked (shorted) to ground as it was connected to a screw on the firewall causing the GEN lamp to remain on continuously. You moved the Brown wire to the correct center terminal of the VR (I can't recall if you polarized the GEN via the VR again). You replaced the VR three times previously in attempts to resolve the GEN lamp issue until the Brown wire misconfiguration was resolved. You have an aftermarket electric fan wired to a switched circuit. Mechanics have said there's something peculiar (out of sorts) with wiring on/near the fuse panel. I realize these are likely issues you inherited. At some point you need to convince yourself you need to methodically unwrap/label each wire and identify each wire by function and match it up to the wiring diagram. You'll get there...faster if you know where each wire is supposed to be connected by following the wiring diagram. Is something drawing (demanding) a higher amperage w/in that cocktail of wires which caused the blown fuse? Sorta/Kinda need to get back to basics of wiring.

 

I do need to get to the basics of the wiring, but the 9amp fuse blew because I shifted too far into reverse, which causes that fuse to blow. Something is out of adjustment on the column and the back up lights. Hasn’t happened in quite a while but I was irritated and was too hard on the shift lever. That’s another issue to tackle.

 

OK There’s another active thread w/ a turn signal &/or steering column switch short right now. On my phone can’t help. Might search for it. Can’t recall year but it’s old iron.

 

I found that turn signal steering column thread. It's on a 1966 Ninety Eight. Obviously, I have no clue regarding any similarities/dissimilarities between a 1961 Ninety Eight & a 1966 Ninety Eight (actually thought it was a 1962 Ninety Eight). Oh well, I don't envy you one single bit in diagnosing the issue because during those years steering columns, switches and the like weren't like some Plug-N-Play switches of later model years. It might be worth your effort anyways & in case it is you'll have the URL link if you find it useful. Have a pleasant Memorial Day weekend.

Uh-oh: is this what I think it is?

 

Thanks for that. Wrong size fuses arrived today, ordered from a different vendor. I’ll update you on the GEN lamp in regards to dimming, etc.

 

The GEN light is on when the key is turned to the run position with the engine off.

The GEN lamp definitely increases in intensity as RPM increases, as does the voltage.

 

Thought you were waiting on a fuse?
Is a 9 amp fuse installed while performing this test?

 

Probably shouldn't have assumed this, but when the 9 amp was in, the GEN light ALWAYS was on when the key was on 'run' and engine off. I'm assuming it's still the case even without the fuse.

As for the GEN lamp increasing in intensity without the fuse, I didn't know that it would do that. I thought there would be no GEN light no matter what, but I was wrong. In this case, the GEN light brightens without the 9 amp fuse in?

The 5 pack of them will be here tomorrow, and I will retest voltage, and the GEN light activity.

 

So, the short answer is you performed this test with no fuse in the 9 amp fuse box holder, yes?

 

Correct

 

Getting late for me. Ironically, your result provides a clue(s) as to what may be occurring.
There are five additional devices, fuel, backup, etc. which are also connected to that fuse. Test each device, does each device work or not work when there is no fuse?

 

With key in on position, no engine on = no gen lamp, no parking brake pedal lamp, no backup lights, no fuel gauge.

With engine running = parking brake lamp on pedal dimly lit. GEN light dimly lit. Zero reverse lamps, zero fuel gauge.