Wiring issue, need insight.

[Straeger]

First off the patient on table is a 1990 325i vert. Initial problem, no heat and cold weather has arrived. I thought maybe my blower motor had died since it seems to be common in vehicles with as many miles as mine. But as it turns out the blower is fine, checked the switch, it's fine. So after an hour of frustrated swearing and multimeter probing I've narrowed it down to the fuse box, I think. There's a good connection to relay K7, the relay itself seems fine but there's no power to fuse number 20. Is it possible my fuse box is bad? I'm a wiring noob so any help would be greatly appreciated.

[Ceeker]

that is possible, after all the main harness runs into the fuse box. you'll have to do more tracing back to the the switch. Secondly..did you check your heater fan resistor? I believe yours has a 4 speed fan resistor. Another reason your blower motor may not come on.

[jlevie]

Are you saying that K7 pin 30 has power? If you insert a jumper between K7 pin 30 and pin 87 is there power at fuse 19 & 20? If so check to see if there is power at K7 pin 86 with the ignition on. A lack power there could be a blown fuse 10. If power is present at K7 pin 86, a problem with the unloader switch in the starter solenoid or a bad relay are the likely cause of the problem.