1986 Cadillac Fleetwod battery drain

JOHNCADILLAC

MEMBER
1986 CADILLAC FLEETWOOD
V8
FWD
AUTOMATIC
101,239 MILES

Regarding a 1986 Cadillac Fleetwood, there is an electrical drain that causes battery to be completely drained if the car is not used everyday. I just bought a hi end new battery and same thing still occurs. I checked recall list for manufacturer's recalls and there have been recalls related to wiring harness getting in way of accelerator pedal behind dash and fuel pump elec. Problems. I have seen nothing that relates to battery being drained so quickly. Any ideas?

1 Reply

WRENCHTECH

MECHANIC
20,757 POSTS

There is a procedure for finding a battery draw like that.

You will need a digital ammeter and a jumper wire with clips on the ends to do this.
First rig any door switches so you can have a door open without triggering the interior lights and unplug the hood light. Remove one battery cable and attach the meter in series between the battery cable and battery post. Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers. Now remove the jumper wire and read the meter. Anything over 50ma is too much draw. The way you locate this is to start removing fuses one at a time until the meter drops to normal level. This will be the circuit with something staying on. Determine what components are part of that circuit and check them individually until the problem is isolated.