Heater control

CHRISTOPHER OWENS

MEMBER
1986 ISUZU TROOPER
2.3L
4 CYL
4WD
MANUAL
13,000 MILES

I am trying to fix the heater on my vehicle. I removed the blower motor and connected positive negative to the battery the blower is working a hundred percent I have another Isuzu Trooper in which I took the AC climate control switches out and replaced it in the other Trooper it is still not working. When I take a test light to the fuse there is no power at the fuse.

8 Replies

CARADIODOC

MECHANIC
33,910 POSTS

Can you see a fuse number? There are multiple fuses in this system, and they are fed from different places. Are there any other systems or circuits that do not work?

When you run the fan motor, observe if it takes a long time to coast to a stop. If it stops spinning almost instantly when you disconnect a wire, it has tight bearings. That will make it draw excessive current and either blow a fuse repeatedly, or burn open the thermal fuse in the resistor assembly.

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Tuesday, June 20th, 2017 AT 11:36 PM

CHRISTOPHER OWENS

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6 POSTS

The fuse number is six, and I tested the fuse with a light and there is nothing I turn the car on and turn the heater control arm my blower fan is not spinning either. I took the blower fan out connected it to my car battery and it is spinning. I took the control temperature switch or whatever you call it out and replaced it with one from my parts truck even though it is a difference switch because it does not have the AC control, it is still not working.

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Tuesday, June 20th, 2017 AT 11:39 PM

CHRISTOPHER OWENS

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6 POSTS

So it looks like six is the rear heater, but I do not see anywhere on this diagram or on my fuse box that says it is for the heater.

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Tuesday, June 20th, 2017 AT 11:46 PM

CARADIODOC

MECHANIC
33,910 POSTS

Do your warning lights work? Check for voltage on fuses ten and eleven. Those are tied right to fuse six. If all three fuses are burned out, look at the "engine relay" under the hood. From what I can see on the diagram, that relay only feeds those three fuses, and really has nothing to do with the engine.

I will be back tomorrow to see how you are doing.

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Tuesday, June 20th, 2017 AT 11:55 PM

CHRISTOPHER OWENS

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6 POSTS

So I was looking at some other threads the heater relay is literally inside the car connected to the heater box. I am going to swap the relays and see if that fixes the issue.