My Riviera's electrical system was behaving for awhile, but lately it seems to be having some issues. If I let the car sit for more than eight hours between drives it refuses to start. All the lights and whatnot come on, but when you turn the key to the start position the starter just clicks. I always have to take my jump starter out of the back and connect it to the booster connections under the hood and let it sit for a few minutes before I can start it. It'll start fine after that. I had this issue when I first got it, but it went away, now it seems to be coming back. I do have an aftermarket stereo with amps and a sub, but even disconnecting all of that I still have the issue. It's like something randomly forgets to turn itself off or put itself into low power mode inside of the car. Is there any common issues that can cause this? It's extremely hard to pinpoint because it takes 8 hours just to see if there drain is continuing.

Another thing I noticed is when my booster pack is connected it displays the voltage. When I connect it up it always read between 12.1 and 12.6 volts, and when I turn the battery pack on to boost it, it jumps to around 12.8 which isn't that big of a difference. The car should still start at 12.1 volts even, correct? Also once the car does start, the voltage reads as high as 15.1 sometimes. I've rarely seen a car output that much wattage. Usually it's around 14.1-14.4 volts. Could this be causing the battery which is brand new to be under strain and not hold a charge correctly? Anyway, any advice would be appreciated. Thanks, Kyle.

Put an ammeter on the main battery cables, then start pulling fuses one at a time until the ammeter drops off.

You can kinda do the same thing with a voltmeter, watch the voltmeter carefully while you are pulling fuses, in your situation one of them should make the voltage jump.

The voltage will spike when the car is first started, it's trying to charge a very drained battery. 15.1 doesn't surprise me. It's a 140 amp alternator and car throw out a pretty hefty charge.

It's possible that your battery is just shot. This would make it not start even though the voltage 'seems' okay, when you hit the key, voltage drops to zilch and it won't do anything.

I have heard of this from the blower control relay being stuck on. Do you hear the blower motor running while the car is shut off?

Just an update on this. I've pulled fuses and let it sit overnight. I started by pulling a lot of fuses and then slowly narrowed it down. I tried the HVAC system, the lighting system by pulling all fuses associated with those functions, and now I think I've narrowed it down to the ELC/IP fuse or the PCM fuse. I'm not exactly happy, considering both are involved trying to find the issue from there.

Do you know of any common drain issues associated with the Riviera? I asked a few people around town that own these cars and they say they've had dead batteries numerous times after the car sits overnight, but never anything as bad as I have.

Didn't you have another post recently about the ELC pump not shutting off? Or was that somebody else?

No, same person, two of the same questions in two different post's.
I just figured that out.

Yup, same one. I figured I'd post an update in the thread that I originally made for it. Sorry about that.

I tried today using the voltmeter and pulling fuses. Unfortunately it seems the voltmeter I have doesn't like a constant voltage for a longer period of time. I smelt something burning and fried the internal circuit in the voltmeter. So it's back to the drawing board. This parasitic drain has got to be the most frustrating thing I've ever encountered. Nothing like getting up in the morning and finding the car dead as a door nail. Wouldn't be so bad if the battery was in the engine compartment where it should be, but no it's under the seat.

It's extremely odd that this only seems to occur at night....

Until you find the source of the problem I'd suggest disconnecting the Battery at night and using a memory saver that you plug into the cig. lighter with a 9 volt battery. It will keep the memory on the radio and PCM unless the parasitic drain sucks that down too.
Didn't you mention you think you've isolated it to the ELC fuse.?
You could pull that fuse every night till you find the problem.
If your not already doing that.!

There are a couple other things. How far is your headlight delay set and how old is your battery? Check how the fog lights and stereo are wired - your parasitic load might be in the stereo wiring?!?

Try setting the headlight delay to a minimum (slide the lever under the headlight knob all the way to the left) and see if that helps.

Probably the easiest way to nail this down would be to get to Sears and buy a "Clamp-on" DC ammeter - then just guide the loop around the wires to see which ones are still passing current but should not be. For wires packed tight in the harness this will take some doing, but is still do-able. Sears sells these in the tool department, set you back $80 or less, look up "clamp on DC ammeter" on their web site to get an idea of what's on offer.

Albertj

What battery did you replace the old one with???/
Did you get an AC Delco with the same CCA rating and the same CA Rating???
CCA = Cold Cranking Amps
CA = Cranking Amps