Oil Cooler Fan Test

[avi8torny]

I can't find the thread which relates to this, but I want to test my oil cooler fan to make sure it runs. What pins do I put power to?

[kepperly]

avi8torny,
the easiest way is just hook up the hot to the black lead at
the motor and the ground to the brown one. Or you can pull
the relay and supply power to terminsal #87 on the relay plug.
#87a is the "at rest" position of the contacts. power from the
temp switch closes the contacts #85 and #86 which then allows the pwer to flow from #30 to #87. If you want to lower the
turn on point. Pelican has a temp switch for BMW that you can retrofit into the oil tank and turn the fan on at a lower temp.
easy deal
keith

[avi8torny]

I was thinking of rewiring the fan so I could turn it on in the cockpit. Are you saying that terminal 30 is hot and I can draw the jump from there?

[emcon5]

ASSUMING Bob Tindel's Pelican tech article on oil cooler fan wiring is wired the same as the cars with a factory cooler, which is a pretty big assumption as I don't have a wiring diagram for that model, here is the way it works.

term 30 is hot, and is where the power comes from for the fan.
term 86 is also hot, and powers the relay.
term 85 goes to the thermostat in the cooler.
term 87 goes to the positive fan terminal.

The thermostat in the cooler is grounded. When the therm gets hot, it closes and grounds out term 87 in the relay, which activates the relay and closes its connection between term 30 (hot) and term 87 (fan) and the fan starts. when it cools down, the thermostat breaks the circut, de-energising the relay and the fan stops.

If you just want to see if the fan is working, you should be able to jump 30 to 87, and when you turn on the ignition, it should run.

If you want to put a switch in the dash, the best way would be to tap into the wire going to the thermostat (85), and run it to the dash. Since all the thermostat does is ground term 85, you would just have to wire the other terminal on the switch to ground, and it should work.

Again, this is assuming that the tech article is wired the same as the factory did it on your car. You really should verify it with a wiring diagram.

Hope this helps,

Tom

[kepperly]

if you want to run a manual off/on switch just add a switch to the coil side of the relay and a ground wire on the other side, as the above post notes. add the wire from the grey #85 terminal to the
switch, and then on the other side of the switch run a wire to a good ground. the relay still works. #18 mtw(motor terminal wire)
is the best as it lays flat and then cover withheat shrink to protect.
keith