kdawghuntnfish

Hi,
I am working on a 1990 truck W/O A/C with a 3.0. My fan only operates on high and has done this since I bought the truck. I have checked past posts and went to check the blower motor resistor. I found the plug with the four wires, but it was not connected to anything. Previous posts were not very clear on where the resistor was located, just stated near the passanger kick panel. I removed the panel and found the blower relay and heater and A/C fuse box, but could not find anything that resembled the resistor. Could someone tell me where the relay is suppose to be located or bolted to?

Saint_Berzerker

Looking at the blower motor from the front, it's on the lower left. It's a big honking white block resistor. I believe it has like 4 wires with slide on connectors on it. It's kinda hidden, but you should be able to find it.

kdawghuntnfish

How is it mounted, with velcro? There is an empty spot to the left on my blower with velcro on the backing board.

Saint_Berzerker

mmmm...I don't really know how it's mounted, sorry.

Are you thinking somebody pulled it out? Never had one?

Do you have any wire connectors that are just hanging there?

It could be that the guy before you just removed it and shorted the high side switch to use the high. It's fairly easy to spot, so I bet you don't have it in there anymore.

yota_krazy

it would make sense because on high, the blower motor recieves power that bypasses the resistor.

kdawghuntnfish

I think the previous owner pulled it out. The wire connector is hanging off the fan. The colors of the wires match the wiring diagram for the resistor. I bet it was pulled out (if it goes twards the drivers side of the blower fan kind of behind the duct). There is nothing mounted to the left of the blower on my truck.

Saint_Berzerker

yep that's it then...gotta buy ya a resistor.

kdawghuntnfish

Thanks for the help Saint_Berzerker.

4Crawler

iTrader: (3)

I have some repair info on my web page about this:
- http://www.4crawler.com/4x4/CheapTri...BlowerResistor

^VooDoo^

Also check the blower motor itself before putting the new resistor in, If the motor is to stiff it will need to be re lubed or replaced or you will burn that resistor up also.

leebee

you had better know a gymnast, that sucker is tucked up under the glove box, right where your passenger floor comes up to meet the firewall and held in by a couple of screws. youll need a shorty phillips and it takes some wiggling to get it oriented properly. i have three speeds from my switch 1,2 & 4 three is non-existant. my back hurts just thinking about what you have ahead of you.

lee

aviator

If you want to get at it more easily all you have to do is remove the glove box/bottom of the dash it is held in by a screw[or two] on the bottom and a 10mm bolt [at far right side] and three screws across the to of the glove box door. you don't even have to empty the glove box. when you get the box down you will have to disconnect the speaker wires as the speaker is attached to this panel. once the panel is gone you can see the whole fan clearly, if you want to visually inspect the fan you can do so by selecting recirc on the heater control panel this will open a door on top of the fan box and you can see the fan through it.
good luck hope this helped Aviator

leebee

oh man, now i find out the easy way to do this! i wonder if i can get back any money spent on the chiropractor?

lee

kdawghuntnfish

I already pulled the glovebox to look for the resistor. Do you know if the resistor is just held on with velcro? I think mine is missing, gone, no where to be found. There is only a strip of velcro where I think it goes.

leebee

that probably holds the floor carpet in place, there should be two small phillips screws, a plug and the resistor below the glove box. it is right up near where the floor and lower dash meet.

lee

kdawghuntnfish

I think I found where the resistor is supose to go. There is a hole in the ducting on the blower fan. I pulled the large duct and there was a metal braket laying in the duct. It has the two screw holes in it. I think the bracket is the backing bracket that is suppose to hold the resistor. There is also a hole in the duct where the blower fan sits that has been Red Greened (duct taped). The resister I ordered should be here Tuesday and then I should be able to figure out how it installs. Thanks everyone for the help.:bigclap:

kdawghuntnfish

I picked up the new resistor I ordered from the dealer today. What's the deal with the dealership price about half of the price than all the parts stores? Thats where the resistor went (up into the duct) and the bracket was the backing plate. I now have all four fan speeds.

Thanks everone!!!! :bigclap:

aviator

Glad to help, congratulations on the successful repair... aviator

ersatz

(gosh! my truck looks nearly IDENTICAL to Aviator's shown directly above--right down to the colo(u)r, wheels, and roof rack!)

Time to revive this thread...

Have a '93 pu with 135k miles that I still sorta love. Weird thing is that the blower has never really had much in the way of medium speed. The lower three notches are low to low-ish, then it goes to full blast at high setting. I did find the resistor (thanks to above posters, particularly to one with links to photos), but it really seems intact. I pulled it out and measured it and it indeed seems to show around 4 ohms across it, with increments of about one ohm from one pin to the next, as expected. I thought i had figured it out when I noticed there was a relay clicking away but, no, it really just activates the entire circuit ( pulled it out, too, and it's fine). I actually have replaced the switch assembly in the dashboard before as the original seemed to be burnt out on one pin, but, again, this basic behavior has never really changed. Is this normal, i.e. does one ohm in series serve to reduce motor speed by about 85%?
I would really suspect the resistor, except it truly seems normal.

Don't really know if anybody wants to weigh in....



(just HAD to make use of one of these great smilies!)