Heater/AC fan blower question (1 Viewer)

[Curran]

Since I bought my 90 4x4 the fan for the heater and the AC has only seemed to work on the medium-high and the high settings. Last week the medium-high setting stopped working and now I'm stuck with off or full blast. Would I be correct in diagnosing this as a faulty heater blower switch or a bad blower resistor? Next question: where is the blower resistor located?

Thanks.

 

[WristPin]

resistor is bad. get a new one. located just above the fan motor. has 2 screws holding it in.

 

[2ndGenToyotaFan]

Yup, resistor.... Just bite the bullet and get a new one, will take 3 minutes to change...

 

[fourwd1]

Definetely the fan resistor pack. Located inside the duct work as mentioned above. When you pull it out it will look like 3 coils of wire inside.

 

[Curran]

Thanks for the help everyone.
I located the resistor pack and pulled it out to get a closer look. The three coils looked rusted and worn out and I found a break in one of the coils. The design surprised me. It seems like it would have been easier to have a solid state resistors rather than the coils. Anyway, I couldn’t get a decent solder repair to hold so it looks like I’ll be ordering a new resistor from C-Dan tomorrow.
Thanks,


CJ

 

[2ndGenToyotaFan]

I tried repairing a few, and it's just not an option... plus they get red hot while in operation... so solder would probably just melt off...

 

[Mace]

Thread from the dead.

my 1990 runner fan goes low, med, med 2(runs as on low), and then high. All of the positions on the switch actually make the fan work, it just goes back to low setting on Med 2. I pulled the resistor and it's one of the expensive ceramic ones.

If I use the "Extra" hole outside the normal plug as a base, the resistance I get from the 4 posts is
L- 1.6
M1 - 1
M2 - 0.8
H - 0.5

0.5 happens to be the internal resistance of the external test wires on my fluke meter btw.

If you run a connectivity between all of the posts (and the external one) they all have connection.
I don't think the resistor is bad. Am I barking up the wrong tree and it's the switch? I just think the switch doing this is weird...

Ideas?

Mace

Ideas?

 

[John in Utah]

Thread from the dead.

my 1990 runner fan goes low, med, med 2(runs as on low), and then high. All of the positions on the switch actually make the fan work, it just goes back to low setting on Med 2. I pulled the resistor and it's one of the expensive ceramic ones.
View attachment 2387622
If I use the "Extra" hole outside the normal plug as a base, the resistance I get from the 4 posts is
L- 1.6
M1 - 1
M2 - 0.8
H - 0.5

0.5 happens to be the internal resistance of the external test wires on my fluke meter btw.

If you run a connectivity between all of the posts (and the external one) they all have connection.
I don't think the resistor is bad. Am I barking up the wrong tree and it's the switch? I just think the switch doing this is weird...

Ideas?

Mace

Ideas?

Sounds right. You can verify by measuring voltage at the blower at all the switch positions to make sure it is increasing incrementally up to 12V at the hi setting - If it’s the switch you should see some sort of discrepancy between that and your measured resistance at M2