1998 GMC Sierra heater fan problem continued

ADUBBER

MEMBER
1998 GMC SIERRA
V8
4WD
AUTOMATIC
11,500 MILES

Hello again,

I am the guy with the gmc sierra I replaced the controll console for the haeter and air cond- I replaced the relay for the fan I replaces the air door actuator, I replaced the heater blower resister
you asked me to test the yellow wire going into the resister with the fan set on low and I did this finding no power. What next?

I am will to pay more for the advise if needed.

1 Reply

KHLOW2008

MECHANIC
41,815 POSTS

Hi adubber,

You should have replied to your previuos post so that whoever was attanding to you can get notification and attend to you as soon as he gets online.

This would keep the history of what had transpired to allow an easier understanding of the problem and recommendations and repairs carried out.

Please do not edit the post as no notifications would be sent out.

Let me know the following.

With blower control speed at Low, you have no power supply to the yellow wire. Let ma know the following.
1. Do you have power at the Tan wire when blower speed is set at M1?
2. Do you have power at the Light Blue wire when blower speed is set st M2?
3. Does applying battery voltage to the terminal of the resistor at the yellow wire work the blower at low speed?
4. Did you test the HTR fuse ( 25A) in the fuse box?

I will copy this thread to the previous one and we will work from there.