Battery drain traced to central locking...

[Eric Huppert]

Peter

Pump should be next to the battery buried in the sound deadening material.
Would think you'd hear the pump running if it was creating a draw. Unless it
came on from time to time!

Try disconnecting connector at the pump instead of pulling fuse. Don't
believe you should have a draw on the circuit unless the pump is running.
Also, determine what else is on that circuit! (To early to go out and look
at the fuse box) If pulling the connecter doesn't solve the problem you'll
have to work back through the circuit and or determine what else is on it

Had a intermittent problem with my 90 200 last year. Started out as a "dead
once in a while", to "dead pretty frequently"... Would normally occur
overnight or if car sat for at least 8 hours.

Finally got tired of the Russian roulette, brought the car in the garage and
put a amp meter (shunt) on the battery. Minimal draw. Went over a LOT of
electrical relays and circuits with the temp gun to see if one part was
hotter than the rest, nothing. Car sat for several hours and I finally
noticed substantial draw (think it was several amps, but don't recall) In my
case it was a flaky door lock heater switch and or controller. Lock was
blazing hot once I noticed the draw! Son has the car now...disconnected the
controller, have the parts, but not a priority fix!.

Quite difficult to determine intermittent issues. Unless you find something
obviously wrong you'll have to put a meter on the car and hope to catch it
when drain occurs....

Eric