[samiralfey]

When I bought the car, somebody had thrown all the ducts away from dash and stuffed a small 12V car fan inside and a switch on the dashboard. This was probably because the heater blower wasn't working and had to have some defrost. Managed to source all the ducts etc. so that's sorted now.

Today I finally got around checking it and what would be the problem. I checked the master relay and hi-speed relay. Hi-speed had some contactor issue but that was easily sorted. I put 12V straight from battery to blower motor and worked ok.

Next checking some wiring and after few hours noticed that the black/doubleredstripe wire going to the alternator wasn't connected. That wire goes directly to the master relay so wasn't feeding the blower switch 12V. I put a wire directly from the battery to feed the master relay.

I measured the brown wire going to the blower switch and it gave 12V. Without the wire from the battery to the master relay nothing.
Also noticed that the blower was trying to turn and it managed to blow faintly for few seconds but then nothing, no matter what position the switch was on.

I wonder where should I look next. Very confusing since feeding 12V's to the blower switch should turn the blower on and as it did for a few seconds but very faintly.

[Bill Hanlon]

Assuming your "I put 12V straight from battery to blower motor and worked ok" statement is still true, I'd take that same test wire straight from the battery and touch it to points A through E that I've included in your wiring diagram with the key on. Note results at each point. Should help pinpoint the problem.

[samiralfey]

Originally Posted by Bill Hanlon

Assuming your "I put 12V straight from battery to blower motor and worked ok" statement is still true, I'd take that same test wire straight from the battery and touch it to points A through E that I've included in your wiring diagram with the key on. Note results at each point. Should help pinpoint the problem.

Ran wire directly to points C,D and E.

C = fan on and through resistor, not full speed
D= nothing
E= nothing

A and B have to try tomorrow.

*edit* Now that I'm thinking of it, maybe it's the switch after all since feeding 12V directly to it doesn't do anything but feeding 12V to the wires behind it engages the blower. But then again ,could all the contact points in the switch be bad?

[Stuart]

If the blower runs at full speed with +12 directly to it, but not in the intermediate speeds, the blower resistor pack could be suspect. They can go bad. As for the switch, a can of spray electrical contact cleaner may help. Spray it down good and move it bak and forth through the different positions to rub the corrosion and dirt off the contacts inside the switch.

[Bill Hanlon]

Originally Posted by samiralfey

Ran wire directly to points C,D and E.

C = fan on and through resistor, not full speed
D= nothing
E= nothing

A and B have to try tomorrow.

*edit* Now that I'm thinking of it, maybe it's the switch after all since feeding 12V directly to it doesn't do anything but feeding 12V to the wires behind it engages the blower. But then again ,could all the contact points in the switch be bad?

C working tells you that A and B will give good results, so no sense testing them.

I should have told you to test D with the key on AND the fan switch in the "almost" high position. This SHOULD give the same results as test C if the wiper contact in the fan switch is good. If the D test fails and the C test works the switch is bad.

With the ignition switch on connect your 12v battery wire to H, I, J and K one at a time noting results. I'm going to guess that all 4 will work as expected and that your problem is a bad contact on the wiper of the fan switch.

[samiralfey]

Originally Posted by Bill Hanlon

C working tells you that A and B will give good results, so no sense testing them.

I should have told you to test D with the key on AND the fan switch in the "almost" high position. This SHOULD give the same results as test C if the wiper contact in the fan switch is good. If the D test fails and the C test works the switch is bad.

With the ignition switch on connect your 12v battery wire to H, I, J and K one at a time noting results. I'm going to guess that all 4 will work as expected and that your problem is a bad contact on the wiper of the fan switch.

You were absolutely right on this one. I wired +12V directly to each wire and all ran the blower, lo-2-3.

Took the switch apart and it was corroded. Cleaned each terminal and also gave the whole console a good lube up and now buttons works smoothly again. Tomorrow going to test the switch, hopefully that solved the problem.

[Bill Hanlon]

I got lucky!

[samiralfey]

Well, the result is, the switch is bad. I got it to run in low and 2nd position but not 3rd or max. Noticed the conneting terminals were rather loose and the main +12V became quite hot so a bad connection there. Didn't want to burn the whole car down so stopped there.

Luckily I found a NOS switch from eBay so hope that will solve the issue for good. I guess no repro switches are made.

[Goatracer1]

In your diagram the 30 amp fuse at the back of the alternator should not be used. The factory came out with an up date to use two 20 amp fuses in parallel instead. The one 30 amp holder would often overheat and melt.

[samiralfey]

Originally Posted by Goatracer1

In your diagram the 30 amp fuse at the back of the alternator should not be used. The factory came out with an up date to use two 20 amp fuses in parallel instead. The one 30 amp holder would often overheat and melt.

Thanks! Will do this to my car, too. Does anybody happen to have a photo of how it looks from factory? Too much of I-did-it-myself-and-saved-money- in this car so prefer the original look...