So I'm cruising down the road today and notice the voltmeter seems to be running high in the 16 to 18 range. Then at a light I smell something burning. I pull over and don't really see anything amiss. I keep cruising and the volt meter is pegged at 18 and the burnt wiring smell is moreso. I get to a friends and we see the wires from the horn relay to the pos battery connector and to the alternator are crispy critters. There's also some battery water sprayed next to the caps. Not much though. The Alternator is a brand new (not reman) 80 amp from Tuff Stuff. Not that I need and 80 amp but that's what they offered. This is a standard external regultor system. So we wait a couple of hours and replace both the wires (red wires in the photo) with 10 gauge where they were previously 12. It starts fine and idles for a few minutes showing 14 volts. I'm cruising home and it jumps back to 16 - 18 volts. I get her to the house and no crispies, but a little more water blow out on the battery top. I've been driving for a couple of weeks since I go her back on the road with no issues. Whatcha think? Thanks, Rob

 

Bad voltage regulator?

 

Yep.

 

My first thought.

 

Fix. Quickly. Please. We don't want to see another one go up to an electrical fire. You might want to look into a voltage regulator compatible with that high-amp alternator you have. About the highest output alternator made back then was a 63 amp.

I'd look into converting to an internal regulated alternator if you intend to keep this 80 amp unit. In an ideal world, the regulator would compensate, but rarely is there an ideal world.

 

X2. Fix soon and do not drive it untill it is replaced.

 

Remember, this is exactly WHY you have a voltmeter. It's telling you something is wrong. You're lucky you ONLY had burned wires and not a burned car. As everyone on here is saying, replace that regulator before you drive the car another inch!

 

also, check your connections at the voltage regulator and alternator. you want them shiny-clean and tight. don't overlook where the voltage regulator grounds to the body.


bill

 

I had the same problem on my Vista . (same alt and voltage regulator) I upgraded to an internally regulated Tuff Stuff alt. but left the regulator there so it looked correct . I have a volt meter and generator light so I had to run the brown wire from the regulator directly to the alternator and all is good . If any one see's there voltage that high you should at least disconnect the small alternator plug to keep it from over charging and melting the wiring or worse causing a fire !

 

Wow, I dodged a bullet and a carbeque! Lady luck must drive an Olds! She won't move again until this problem is fixed! I've seen threads on here about converting to the internal regulator so I'll look into that further. But in the interm, I'll change out the voltage regulator and check the grounds and go from there. I'll update the result. Thank ya'll very much! Rob

 

Changed out the regulator to the oreilly house brand and ran it about 15 minutes and then went for a 5 minute low speed cruise around the neighborhood. It was showing just shy of 14 volts on the gauge. Although the needle is a bit jumpy. I can't recall if the needle was steady before or not. It seems like it did move a little. I'll take her out again this week for some higher RPM'S and hopefully that will be it for this near miss of a carbeque.
Rob

 

That certainly sounds like where it should be. I think you've solved your problem, but keep an eye on it for a while as you say.

 

it would be worth noting what an actual vom/dvm reading is, factory gauges are notoriously inaccurate.


bill

 

Did you get a mechanical reg or electronic one? Mechanical regs can cause the jumps that you are seeing.

The electronic reg would be as light as an empty beer can (almost...)

 

I can relate to the empty beer can analgy Rob. And this one is much lighter than the original and doesn't have the exposed ceramic looking coils on the back. But I wasn't aware of a electronic or mechanical version. They did list a couple of p/no's that were for 61 or 63 amp alternators. Could the higher 80 amp alternator be causing any issue?


These are aftermarket underdash gauges and the cheap parts house versions at that. I'll be getting a good autometer or comparable set one of these days.

How would I check for actual voltage from the regulator? Or the alternator? I have an electronic volt/ohm meter.

Thanks,
Rob

 

Sounds like you got an electronic one.

The 80 alt should not be an issue (unless defective), until the electrical demand from the alt goes above 63A. Below that, it should act like a stock unit.
Any real reason you went with the 80A vs the 63A? High power accessories added? If not, then demand would rarely exceed 60A or so.

To measure, just put your voltmeter across the battery while the engine is running. To wire it in temporarily to monitor it while you drive, connect to the courtesy light feed, or plug into the lighter socket, or across the radio feed if you want it switched.

 

Hey, you coined a new word. I like it.

 

[quote=Lady72nRob71;198243]Sounds like you got an electronic one.

The 80 alt should not be an issue (unless defective), until the electrical demand from the alt goes above 63A. Below that, it should act like a stock unit.
Any real reason you went with the 80A vs the 63A? High power accessories added? If not, then demand would rarely exceed 60A or so.
quote]
No real reason except when I was looking, this was a new unit as opposed to a reman. In hindsight, I could've saved about 30 bucks by going with a reman from Rock or O'reilly with have lifetime warranty. No power accessories except for the antenna and the top. I will eventually add an amp to the stereo but I imagine a stock 63A would suffice for all of the above. I may go ahead and have this alt checked out to see if it is defective. Could the bad regulator have funked it, or anything else, up?

Yeah, I stole that from a radio traffic DJ I heard several years ago. We hear about a "carbeque" a few times a month down here. Thankfully it's not usually a classic.
Rob