heater fan switch/relay/fuse/motor 89 22re

[peterng]

G'day,

I would like to elaborate on the observations that I have made in relation to this problem. This is all related to the fan/heating system for the cab, not the radiator fan.

When I bought this truck a few years back the fan switch would only work on the high position. So this past winter it gave up the ghost. I thought naturally tht the fan switch would be the problem so I picked one up at the Toy dealership for $70. The backlight behind the heater/fan switch worked this entire time. So the new one went in and no dice.

Next I tore the fan motor out, hooked it up to a couple of wires run off the battery and it spun.

Next I checked the fan fuse. While in that area I noticed the relay made a noise when the fan switch went from the off position to low.

voltmeter in the fan fuse receptacle reads ZERO with switch on.

So...... my questions are ...

1) any thoughts?

2) what the hell does that relay do?

3) how does its(relay) function differ from the switch itself?

4) can I bypass the relay and run it into the fan fuse?

5) how do you test a relay?

I'd like to avoid buying any more new parts trying to diagnose this problem. I'd feel too much like a Canadian Tire mechanic if that were to happen.

Any assistance would be appreciated. I already have no heat so if all else fails I'll wire a 12" fan to the ceiling and point it towards the windshield to get me through the winter.

Thanks,
Pete

[Sidney]

Heavy b l o w e r resistor (Toy EPC calls it a cooler/coil resistor,fan coil resistor) for fan # 88635-89103 (85-86 4-Runner,4 speed fan) & 87138-89105 (89 pickup)

http://www.4crawler.com/4x4/CheapTricks/Blower.shtml

Sidney® ™
Repairs tv's,vcr's,home/car audio out of my home
E-mail:sidneybek@yahoo.com
Dartmouth,Nova Scotia
Canada
1985 Toyota 4-Runner,solid front straight axle,factory cruise control,sunroof,22R-E,W56,RN60LV-MSEK,rusted rear step/towing chrome bumper with 245 000 KM

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[peterng]

Sidney, you were right that my resistor was gone, but I still had no dice when I replaced it. I was wondering when I read your reply as to why mine still didnt work on high. The relay was making a noise, but tonight, with no other ideas, got into the wiring diagrams and decided to cross the red and white leads in the relay boot with the realy out. as soon as I did, it turned on the blower motor, and all of the fan positions on the switch worked, even with the key out. I guess the relay sits in the open position til the fan switch hits the intitial low position to close it. So I have deduced that the relay is screwed.

So anyone who has a blower fan that only works on high, replace the resistor. If nothing works, you will likely have to replace the relay and the resistor as well if it only worked on high previously.

Awesomely fullfilling most excellent waste of time this project has been not to mention the $120 worth of oem components, but nice to have that damn blower fan working again !

Thanks sidney, you opened the door to success for me on this one.
Pete