Fan only runs on setting 4

[m_w]

Tonight's electrical problem to solve is the fan/blower in the hvac box. It only works when I turn it to the highest setting (4).

Can anyone point me where to start looking?

[davidc89]

http://store.delorean.com/p-7593-resistor.aspx

Would be my guess. That controls all your fan speeds. I would look there.

[m_w]

http://store.delorean.com/p-7593-resistor.aspx

Would be my guess. That controls all your fan speeds. I would look there.


Really? I didn't know that... I had that unplugged when I was trying the fan out.

I actually ordered a new one and just installed it. I'll try this out again tomorrow with that resistor plugged in. Thanks!

[Rich]

Really? I didn't know that... I had that unplugged when I was trying the fan out.

I actually ordered a new one and just installed it. I'll try this out again tomorrow with that resistor plugged in. Thanks!

Good call.

From the wiring diagram: That resistor pack is involved in all 3 of the lower fan speeds with only the 4th speed on a separate and parallel circuit.

So if the output connection of the resistor pack to the fan is bad - or when it's unplugged like it was when you were testing the fan - then the fan would work only on 4th speed.

[m_w]

Good call.

From the wiring diagram: That resistor pack is involved in all 3 of the lower fan speeds with only the 4th speed on a separate and parallel circuit.

So if the output connection of the resistor pack to the fan is bad - or when it's unplugged like it was when you were testing the fan - then the fan would work only on 4th speed.


Yep that's what happened. Installed and plugged in the new resistor and the fan works on all 4 speeds.