rpsutherland2

My 1991 C4 has an issue with battery power drain. it will not stay charged over a day. I have checked all the fuse circuits in the bonnet and there is nothing draining the battery there. My alternator light comes on occasionally but the battery charges well and, by he way is new. Anyone got any suggestions?

Thanks for your help.

Vandit

Are your interior lights coming on after you turn off the ignition and open the door?

rpsutherland2

yes. they are working properly.

LouZ

You state that you checked all of the fuse circuits. How?

The proper way is to use a VOM between the battery and the ground, measure the load, then pull each fuse individually and measure the milliamp draw. See if it drops significantly when you pull a particular fuse. Then you have isolated the culprit circuit, and then go from there.

Also, besides the interior lights, check the glove compartment, bonnet and hood light to see if any are on. You can open each up and immediately feel if the lamp is hot.

rpsutherland2

Thanks but I have done all of that.

Harry Apps

Disconnect the battery and try doing a simple current drain test using a 5W bulb to ascertain how long until the battery goes flat. If it's quick, get another battery.

JasonAndreas

What is the current draw? When you put the ampmeter inline with the battery did you do so BEFORE disconnecting the ground wire?

The Stig

Only a few items are un-fused that can cause a drain if the lights, etc are working. The battery itself, alternator, starter (including engine ground strap), and any aftermarket alarm.

I went through rounds and rounds of investigation to cure an 18.5A drain. Battery would die in 30 mins. The metal coiling on the heat exchanger broke away from its sheathing and tore its way through the big red wire on the starter.

Check those items next. Good luck.

dimma man

How much mA should you measure with all fuses out?