Bad day -- Ok here is the deal. I scrapped my Bose last week and had the stereo store put in a nice JVC with Kenwood speakers. Stereo shop has the car for the afternoon and when I get there the mgr. says they could not figure out how to wire the car to get the power antenna to work but I can bring it back and they will fix it. Then I get in my car and it does not start. The mgr. says the interior lights etc. were probably on too long during instalation and gives me a jump start. A little aggrivated but I go home - stereo sounds great. Next day car doesn't start. I put on a charger on for the night and things look fine. Two days later (car was not driven) I pack for the lake and take the Vette for the nice 1 hr ride. 20 min into the drive in a tiny town my radio and dash go dead with the engine following. I luckily find an old guy who gives me a jump start but when I disconnect the alt. meter goes down to nothing and I stall out. We connect the battery to a big charger for about an hour which gets me enough battery life to get back home without a tow.

Question: Could the stereo guys have wired something up wrong to cause this sort of a problem? It all seems so coincedental with the stereo installation. Car is a 1990 with 30k - never had any problems and battery is new last year. Any thoughts are appreciated. Apologies for the long story but its been a LONG afternoon!

 

Sounds like your not getting any power from alternator. Look for any connections that may have come loose or off.
On my 86, there are 2 fusible links between alt terminals and battery, they could have toasted one of those.

 

Bad question by me -- am I looking for an actual fuse in a line that runs between my alt. and battery? Thanks for the help.

 

It's sort of like a fuse, but is actually called a fusible link and is somewhat different from a fuse. Basicaly does the same thing though; will cut the flow of current when blown.

It's inline with a wire, are usually round and maybe the diameter of a dime, white in color and plastic-looking.

Jake

 

What does your voltmeter read with the engine running and running for awhile? Is the red battery symbol light on? If so, the alternator is not charging the battery which matches your symptoms. Normal voltmeter reading with the engine running is 14.3 volts engine cold and this drops to 13.3 volts when the alternator gets to its operating temperature. Below 13 volts, and the alternator is suspect. Also, you need to measure the current flowing out of the battery with everything off, it should be less than 50 milliamps. You will have to defeat the underhood lights and wait for the courtesy lights to time out to measure leakage current.

 

Thanks for all of the advice. Took it to autozone and had it diagnosed - altenator is toast. Me and my 10 yr old son put it on in about 1/2 hr. Works great. Clipped the serpintine so we did not have to route it again - PITA. Everything seemed very coincendintal with the stereo installation which threw me off. Just had the thing apart to replace the air pump a week ago. So within one week, air pump, complete stereo system, and alt. When it rains it pours.

 

All you had to do was observe that the red battery symbol light on the dash was lit and also the below 13 volts on your voltmeter, all indicating that the alternator had no output.

 

Lesson learned I guess...

 

Not quite, The stereo store ruined you alternator. If they knew what they were doing, then they would have disconnected the battery before starting the job. Jump starting these cars is always a BAD idea. The weak battery overworked the alternator & fried it. An alternator is not designed to charge a dead battery, period!

 

I would have to agree with this and that it's not coincidental. Sounds like they might have shorted something during install. Just to be safe, I would also check to make sure you don't have the short still in place by checking on current draw while the car is parked and key out. Easy to do, just put an amp meter (most volt meters support this) between the negative battery cable and negative battery post and take a reading.

 

 

Every circuit in a C4 except the starter motor is fused or has a circuit breaker. If a wire was shorted, a fuse would be blown and no current would then flow in that wire. Measuring leakage current will NOT find a shorted wire!!!!!!!!!!!!!!!!!

 

Shorted wire I agree, but it also depends on where the short is, one of my high power transistors shorted to ground in my RTD module and I was pulling 2.2 amps with the key off through one of the shocks, but not blowing any fuses. The only way I discovered this was by measuring my current and pulling fuses until I found the circuit with the issue.

Something caused the alternator to fry and I agree a hard short should have blown a fuse, but the fact that it didn't would have me extremely concern that an underlying problem may still exist.

Then again it could just be entirely coincidental that the alternator went because the new stereo system was pulling a lot more juice then the old alternator could handle.

 

Thanks for all of the advice. I now believe the stereo installation/altternator issue was a coincidence. The stereo shop confirmed that they always disconnect the negative terminal before wiring anything up. He mentioned that the interior lights were on for awhile when they were first assessing the instalation and then they did fire the car up and tested the stereo system several times before I picked it up. I have been driving the car for several days now since I installed the new alt. with no issues and the voltmeter reading 14-16 consistently.