Hi,

My C2 is a complete reno with new everything. For the last year, she's been running great and all is working. Last weekend, we were at a cruz in until late evening and something odd started happening. When I turned the headlights on, they work, but dash and lights are all very dim. The dash volt meter shows a large draw on the battery system as well. Turn the lights off, and all is back to normal. This would lead me to believe I have a short or a bad light switch (although its new too). To add to the confusion, this is where it gets strange. Even with lights off now, when I'm driving down the road with the stereo on, and put on a turn signal, the amp on the stereo (separate on the back deck near woofers) goes out. The blinkers work fine, but power drop is obvious. I think the amp just doesn't have enough power to pull, so it shuts down. This has me perplexed as to where to look for the short??? Seems like it might be across several circuts. Seems like a ground issue, but every area I check, all looks OK. If you have any suggestions as to where to look, or proceedure to check, I'd love to hear it. I'm about to pull the dash, and we all know how fun that is!

For added insight, note that I replaced the alternator, and voltage regulator (with a high end one vs standard) last summer. While it works great all last summer, is it possible there's something there?

I hope someone can offer some insight as to where to start. Pull fuses one at a time? Any thoughts appreciated.

Emaiil me at: jim@janicekmedia.com

Much appreciation to all you wizards who've always been so helpful to me.

Sincerely, jim Janicek

 

I read your post and I was thinking what I would do. Obviously something is putting a big load on your system. Or your charging system is faulty. I would use a process of elimination and I would start with big items first. Your amp to begin with. You need a better monitor for your load an amp meter would be what I would choose. I know I would not want to pull the dash if I didn't have to. Not much help but thought I would try. Greg

 

Jim, We need to know what Amperage the output of the Alternator is. Your Radio Amp is Drawing what amount of Power? I'm suspicious of your Battery, Grounds, (Particularly to the Chassis and Engine Block).
Diming of Headlights often is caused by poor Ground Returns. Keep us informed. Al W.

 

Sounds like you're not charging the system.

Before you go disconnecting stuff, put a voltmeter on the battery and see what it reads at idle and when you rev the engine. With the lights and stereo turned off, If it doesn't go over ~13.5 volts when you rev it up, you're not charging and need to look at the alt/regulator/their wiring again.

 

My first thought is the voltage regulator

 

OK Per your questions here's what I know... I too suspect ground issues, but have checked the various ground areas and can't locate anything that looks suspect.

Recent changes I've made.

1) Added an on/off switch to the positive side of the battery between the battery and starter.

2) Delco Remy (new Alt.) 3 pole plug w/neg pole ground. 66 amp / 12v.

3) Battery (new) Optima red top 12v gel cell.

4) Voltage Regulator (new) Niehoff *Is it possible I got the wrong one?

5) Stereo Amp. (cheap) Visonik V2208 110w 2 channels.

Is it possible I put in the wrong distributor or vr ?

Thanks again.

 

I will check the voltage on the battery while running to see what gives? Then report back. It's certainly never had trouble cranking over the system in the past...and still doesn't. I have noticed that when I first drive around after parked for a week or two, there is a strong negative draw on the battery. Eventually after driving around for a while, it balances out. I assume this is because the alt. charges it back up to normal.

JJ

 

If this turns out to be Alt. and VR. Please offer suggestions for a solid powerful replacement. I don't want to melt my harness, but would love to be running a good voltage so everything works.

 

I believe what you are seeing is the Alt. struggling to recharge the Battery. Do you have a Battery to change out with? Sounds like your Battery just may be the problem. Al W.

 

OK. Voltage with engine off 12.4 volts. Voltage with engine running 12.6 volts. Voltage at 15k rpm 12.6 volts. Seems normal. Could it be that the light switch (although part of a complete restoration from back east) could be bad? It's obviously the switch that introduces the short and heavy draw on the battery. The dash lights are barely a glow, very slight... however, things like the blinkers, brake, lights, highbeam all are quite bright. So the fault must be in the lighting circuit and it's ground? The only thing that throws me a curve is even when the lights aren't on, but the blinkers are used, (and they work fine) the power draw seems to be enough to kill the amp in the back. Maybe it's two issues, a low battery, and a short??? Thoughts?

JJ

 

No that's not normal. It should go up when you rev the engine and should be at least 13.5 at the battery when you rev the engine with no accessories running.

If you pull your alternatior off, most auto parts stores can check it usually for free. That's just a couple bolts and easiest thing to try first.

 

OK let me pull the alt to see what it tests at. Is it possible that the "more expensive" checker auto VR i installed last year is holding back the amps needed? Also, if the alternator does test bad, should I consider going with a higher output vs 66amp 3wire I'm currently running? Would it be safe to go for a 100-110? Thank you so much for input.

 

One thing to keep in mind. I'm running a GM 350 5.7L w/Richmond 6 speed. Electronic ignition with the edelbrock 650cfm carb.

 

Take your battery at the same time and get it checked

George

 

you stated in an earlier post

"Recent changes I've made.

1) Added an on/off switch to the positive side of the battery between the battery and starter."

Is the switch wire 6 ga.? Can the switch handle a 100A kick back of the starter? If the switch is breaking down it will act as a load on the battery

 

good thoughts. I'm beginning to suspect the Alt as well. Here's why, last time I replaced the alternator (last year) I also changed out the alt. fan with a billet version of the same. When doing this, the fan sits 1/4 further from the body of the alt. vs original. This may be causing overheat and early death. Just thinking it through. The switch I installed is a 100amp Caltern, (the black one with the red key) and the cables I've used to connect it are all standard, heavy gauge battery cables. I will pull the alternator to test. The VR I have is a Bosche 17053 (new) anybody think this could be an issue?

 

If all the accessories are turned off, the engine does not draw anywhere near 100 amps. You really need to see at least 13.5 volts at the battery when the engine is revved up. If your switch is on and conducts electricity, that's not the problem.

Yes, the VR could be the culpret or it could be both (one will often take the other out on its death), or the wiring between them and the battery.

I just figured that the alt was the easiest thing to try first. It is a PITA to pull a passenger-side the battery out of a C2. If the auto parts store can check the VR and you are comfortable that you can properly reconnect it when you put it back, take that too.

 

I would check to make sure the voltage regulator is properly grounded to the base of the horn relay. I would also remove the screw that attaches the horn relay and and make sure it has a good connection to the rad support.

 

OK, pulled the alternator and took it in. Sure enough, even though it was new last year, it failed 3 times on test. Bought a new one with a small amount more amperage (72amp) stuck it in, and vroom, nice lights! So, while I'm not certain I found the ultimate cause, it certainly is a significant improvement. The ground on the VR is screwed to the metal radiator frame it's mounted to. I could suppose to reconnect to the ground on the horn relay. The HR is about the only thing on the entire car that's original and never had an issue. I will double check this. One thing is for sure, when I fired the engine, this time I got a nice POSITIVE serge of volts on the dash meter. About 1 min running and it balanced at center. Turned lights on and got very little if any negative draw. I'm very grateful to everyone who contributed to this and saved me some big hassles! Thank you. If you think I should continue and check the VR, and grounding to the Horn Relay... let me know.

Best, Jim

 

Sounds like you got it fixed. Just for grinns, now check the voltage at the battery when you rev the engine and tell us what it is.