Chevrolet Suburban Battery Drain

thowe1959

I have had my 1999 Chevy Suburban in to the dealer 4 times for phantom battery drain. We'll wake up in the morning and intermittently the battery will be dead. No lights left on, no doors left open. the dealer replaced the 4X4 panel once and the battery twice to no avail. They seem stumped. Any ideas?

Mr_Shiftright

Well, it shouldn't be difficult to determine or at least isolate. What the dealer should have done is place a meter or test light in series with (in line with) the positive battery cable, with ALL systems shut off and all doors closed, and if there is a hood light, that removed or disconnected.

In theory, with a battery drain, you will have a meter reading or the test light will glow. A meter might be better because if the drain is very small it may not light a light. Anyway, once the meter or light is registering, you pull one fuse at a time until the light goes out. This gives you the circuit that the drain is in.

Then it gets tougher. Obvious culprits are dome lights, courtesy lights, etc. So once you know the circuit you may have to disable every component, one by one, in that circuit until the light goes out or the meter stops reading.

Sooner or later, victory is certain, but you have to be patient and methodical. Sounds like the dealer was neither. I can't imagine why they replaced the battery. It could have been load-tested.

0patience

About the quality of the mechanics now adays.
A simple battery drain and they are having trouble with it?
The young pups in shops are more concerned with what the computer tells them, then anything else.

Don't get me wrong, there are many really good young mechanics coming into the field, but they are usually trained by a mechanic who is good.

Sorry for the rant.

jgmilberg

My Aunt's S-10 had the same problem dealer couldn't find it, took it to 2 others who couldn't find it, finally the 4th dealership found the problem. It was the vanity mirror light on the passenger side, switch was bad and would intermittently come on by itself draining the battery. Hope this may help. But the dealers should be able to isolate the circuit. You can too, just find the stuff that stays on with the ignition off and pull the fuses one at a time each night till you go out and start the thing the next day. Another way is using a test light, disconnect the positive batt cable, put the test light between the battery and the cable, the light will light up as long as a drain is present, pull the fuses one by one until the light goes out. Keep in mind the computer and radio both put a slight drain on the system, but you will see immediately what the circuit is when the fuse is pulled, the light will almost go out completely.