Hello, I have a problem with interior air fan. When I push slider from minimum to maximum I hear only sounds (clicks) in relays (first click when I start move slider and second when it is in maximum position) but air fan does not work. I removed, cleaned and checked commutator and 2 graphite brushes after that I connected to battery and it works but when I put it back in car still nothing. Any solutions?

 

There is a procedure for troubleshooting this in the FSM. It's a pretty common fix, with a bunch of multimeter work. Just tedious, but not difficult. Getting a set of long multimeter leads help make it easier.

As far as the fan not working, it could be wiring, it could be a relay, or it could be the transistor to drive the motor is burnt out. The FSM has the procedure to troubleshoot the whole circuit, step by step.

The link to that section of the manual is here:http://www.rotaryheads.com/PDF/2nd_g...AC_systems.pdf

The wiring voltage will be the first thing you check, along with the relays. The transistor should be the last thing to check.

If the transistor is burnt out, here is the link to what you need: http://www.mouser.com/ProductDetail/...XWgDeMrLUFE%3d

If you end up needing to replace the transistor, make sure to use some thermal paste for computers or similar to seal between the transistor and the heatsink. If you just put them back together and run the fan, the transistor can overheat and then you have to replace it again.

 

When my fan went it was the same. It did not work in car, but would work hooked up directly to battery. I replaced the fan and all was good. I would say your fan is probably bad. If the fan is original then I would just replace. I did not make any other checks myself. I figured 25+ years out of that fan and it was time to replace anyways.

 

Solved. Thank you for suggestions and sorry in my delay in write back but having 2 kids now makes me no time for other topics. Anyway and hopefully because I do low millage only reason were dirty electric contacts :-)

 

I know that feeling.... kids, no time for any hobbies lol

I wish i had the time to clean every single contact in the car.... would probably make some gremlins go away.

 

If the problem returns then you may have cold solder joints in the logicon's fan control switch. I have a thread about checking and repairing it. I also repaired smikel's logicon for the temp control slider. Photos on both threads would help you identify the problem solder joints. They usually look like a dark grey and flattened nail head.

You could press in the fan slider switch (not too hard) then pull back on it while sliding it from OFF to MAX. NOTE: You will hear 1 click of the fan relay engaging from OFF to MIN setting and from MIN to OFF. That is a normal indication. If you hear relay chatter as the slide is moved along its track or it chatters when set at a given fan speed then the problem is a cold solder joint in the logicon.

Shoot me a PM if you have any issues with checking it.

Cheers,
George