Battery drain - interior blower problem?

Shaun@Belfast · 01-08-2003, 06:24 AM

Hi. I have an '87 944 8v which drains its battery after a few days. The battery is good. The drain is 0.08 amps and a little more than it should be. I removed each fuse one by one but found no change. ON removing the #1 relay (interior blower) the drain dropped by 0.06amps to an acceptable 0.02amps. I suspected the blower, but disconnectiong it makes no difference (the relay was reinstalled for this). Basiscally the relay seems to be the key. Of course it is different to the others so no simple substitution is possible. Also it has 5 contacts as opposed to the usual 4 - why? If i knew why this might help. Suggestions please. The 4 position blower switch appears to work perfectly

Thanks

Shaun@Belfast

SoCal Driver · SoCal Driver's Garage

Many serious battery drains can be found to be from a bad radiator temp switch (turns on the radiator fans). This switch and it's related circuits will run one of the fans at a lower speed when the key is turned off. This is to keep the cooling system from overheating and blowing the hoses off. The switch's temp range becomes skewed and it takes longer to change state or even just sticks.

1.2gees · 1.2gees's Garage

Try pulling it off, turning off the ignition all the way with the relay off, and retest. Repeat for the power window relay, and see if it makes a difference. Also (ofcourse) check to see if the blower relay is staying stuck.
Ahmet

Ebs · 01-10-2003, 06:53 AM

I had a problem with my battery draining if I did not drive the car at least every second day. I have a high tech immobiliser that seems to be doing it. I installed a modulator switch, which disconnects the battery, which I turn off when I am not using the car frequently.

Shaun@Belfast · 01-20-2003, 02:19 AM

Problem solved!

I purchased a new relay (£14) which cured the problem. The old one had burnt its insolation slightly and was leaking a little current away. When I retested the flow through that circuit with an ammeter (before installing the new relay) taking the fuse out did make a difference. Don't know if I just missed this on the initial trace or not - think I might need glasses and I was using a meter with an LCD readout!

Thanks

Shaun