ktmhans

Recently picked up the truck for plowing, seamed pretty clean. But as we all find out when we start tinkering. Today challenge is the heater blower doesnt work at all. Ive tried searching and cant find this answer so, sorry if its been hashed before.
All the fuses i can find are good.
Ignition on, off to low, med,high. The relay solinoid behind glove boxs clicks.
The resistor looks good. No power ever gets to it though.
The blower switch has a nice clean feel to amd no jigling makes a difference.

Can the switch give power to open relay and yet not send power to resistor?

Any help would be great!

ktmhans

Okay so I pulled the switch out, seems like I have power through the switch with a continuity test. But I have no power coming to the switch. Anybody know where it goes to

Gamefreakgc

Closest I could find see A23 & B23:

ktmhans

Thanks for that, i dont see the relay in the diagram. Im gonna hope that the relay somehow isnt pushing power to the switch. I dont get any power to switch or risistor. Even though i can hear and feel the relay clicking, doesnt mean the juice is flowing i guesse. I dont know.

Gamefreakgc

Missed that part of your post. Yeah, most likely the relay. I think they run about $20 unless you can pull one from a junkyard. I've not heard of one going bad, I've got 284k miles and it's going strong, only had issues with the switch short-circuiting (which yours is good).

Or you could try opening it up and soldering it if you feel adventurous, most likely if it's broken you'll see evidence of a break or burning from a short circuit.

scope103

What about the fuse you didn't find? (It's hard to help you when you don't really tell us what you did.)

The heater switch grounds the line from the heater motor; if you can't find 12v at the switch, then you have an open on the motor side. The motor is powered through the heater relay, through the heater fuse. The heater relay itself is powered by the gauge fuse, which is why you can hear it working but no 12v is getting to the motor (even if the relay is working).

My guess is a blown heater fuse (right next to the heater relay), or a dead blower motor.

j2the-e

All the fuses you could find are good? Did you find the heater fuse? Did you check for 12v to the blower motor itself?

j2the-e

I guess I type too slowly^^^^What scope103 said

RAD4Runner

Resistor and blower switch are on the negative side of blower motor. They provide ground to motor and to negative side of relay coil when switch is NOT in off position. If your negative (black) test probe is on ground, do not expect to see any voltage on resistor or switch (unless switch is on OFF position, when you'll read voltage leaking through relay coil).

If 22RE, since relay clicks follow notes "2" in red below.
If you get 12V on both sides of fuse, you should also get 12V at terminal 1 of blower motor.
Now measure between terminal 1 and 2 of motor. If you get 12V there but motor still does not work, most likely the motor. To verify; disconnect blower motor, measure resistance between pins 1 & 2 OF MOTOR, compare with what other owners read (Gotta ask those who have measured theirs).

Fuse and relay scope103 mentioned above are here:



More details on my own build thread.

scope103

Happens to me all the time.

ktmhans

Ok, first off thanks for all the great replys. I said i checked all the fuses i can find because the fuse box under hood, i cant read the top of box. And the 2 fuses under the blower relay were good.
The relay WAS BAD it still clicked when you moved the switch to low. I actuall tested the coil on the relay and it was good. And not really knowing exactly what i was doing i moved on. Shame shame. But now i know.

Just to recap for some help to people searching
Blower not working
Blower resister looked good, but never got power when switch was switched on
Blower switch tested good but had no power coming to it
Blower relay "clicked" sounded like it was functioning. I removed the cover off the relay. And couldn't get continuity while closing the switch and testing between the large terminals. This is where i should have stopped to replace.

If you need to get to switch on an 89 pickup, mine at least, remove glove box side of dash, remove steering wheel down part of dash, then pop apart the center console trim pieces. Remove 4 bolts that hold radio cage. You should be able to reach up pop the switch out without breaking the very hard black plastic tabs and remove. . Not really that big of a project , i only wrote all this out because i couldnt find it anywhere.

Thanks again to all the great replies!

RAD4Runner

Cool.
So you replaced the realy and all's good now?

Thanks. We appreciate it when fellow members share what they learned.
Happy weekend.

ktmhans

[QUOTE=RAD4Runner;52127741]Cool.
So you replaced the realy and all's good now?


Yup, $18 at autozone, good to go for now. And now I can change the light that's blow to light up the switch board.