Hello All,

This is in reference to my cousin's 1997 Hummer H3 w/90k miles. We're working on a problem w/his blower motor. The blower motor does not function at all. When the A/C button is used, the light turns on and off as it should, and we hear an erratic "clicking, electrical" sound from the blower motor area. We hear the same type sound in the same area when using the switch to change air direction flow (feet, dash, etc). But that's all.

A little history:

He bought the H3 5 years ago. 2-3 Years ago the blower motor stopped working. It did not function at all, regardless of the speed setting (1-4). He took it to GM. They said it was the harness and resistor, so he paid them to replace his harness and resistor. It then worked as normal.

11 months later the blower motor stopped again. He took it back to GM. They replaced the harness and resistor again, this time under warranty. However, the blower still did not work. They stated it was not the harness, but another problem they would need to look for. He didn't believe them.

So now, over a year later, he and I are working on it. The harness and resistor look good; in fact, they appear as to be new. There are no signs of arcing. We replaced the blower motor yesterday with a new one (the old one was a replacement w/a manufacture date of 2011). But the new one doesn't activate.

My next step is for him to replace the relay that is in the harness. Beyond that, I was going to pull the climate control unit itself and see if it was somehow unplugged there.

Any suggestions or ideas?

Thanks,
Bill

 

Update: My cousin replaced the relay and it still doesn't work.

 

1997??

relay is for top speed only. you have 12v on motor?
if so you can jump resistors to ground to check.
you should be looking at the wiring diagram to fix it.

 

fuse? switch???

 

Run power to blower motor and verify it works. Then use multimeter and back track everything

 

There is no 1997 H3? Are your referring to the H1? Either way, you may check to see if the new recall for H3's has been completed for your H3. The recall is as followed:

HVAC CONNECTOR WIRE FAILURE

Recall Description:

General Motors has decided that a defect which relates to motor vehicle safety exists in 2006-2010 model year Hummer H3 and 2009-2010 Hummer H3T vehicles. The connector module that controls the blower motor speed in the heat/vent/air conditioning (HVAC) system may overheat under extended operational periods at high and medium-high blower speeds.

Safety Risk Description:

If this condition occurs, there is the risk that the heat generated could melt the plastic surrounding the connector module, which increases the risk of a fire.

Repair Description:

Dealers will replace the female connector and harness, free of charge.