'98 Grand Cherokee - blower issue

[PacificEd]

My 1998 Grand Cherokee's blower motor has quit blowing. It doesn't work on the A/C or heat side or at any speed.

Any leads on what to look for first? I figured it is probably the blower motor but they also show a blower motor resistor. Any ideas where to start or how to diagnose/find the bad part?

If it matters: 1998 Grand Cherokee Laredo 4x4, I6 4.0L engine. 135,000 miles.

 

[Johnnie Walker]

Start by checking fuses. And check/replace the resistor first.

 

[macgyvr]

Ed, is it a manual or auto hvac system?

mac 'agree with replace resistor' gyvr

 

[RedHeep]

Agreed, resistor. It's the part that modifies the amount of electricity the motor gets to adjust the fan speed.

 

[PacificEd]

Ed, is it a manual or auto hvac system?

mac 'agree with replace resistor' gyvr

This sounds dumb, but how do you tell the difference?

I'm guessing manual since I don't see anything that leads me to think it has the automatic temperature control.

 

[macgyvr]

Three dials the same size is manual

Auto has an auto setting

mac 'messed with both' gyvr

 

[PacificEd]

That is what I have. Manual.

Man, the only way to afford these things is to buy from Rockauto.

Where is the resistor located?

 

[partsxj]

It could be a bad connection. My 98 ZJ does the same thing. I usually reach under the glove box, there is a harness there, and when I move it the blower motor comes back on. I hit a good bump the other day and it came back on. I have looked at it, but could not find the problem yet.

 

[IllianaXJ]

Usually when the resistor goes the fan works on High speed and nothing else.

I would check fuses first, connections second, then put 12v to the blower and see what happens. The resistor connectors have a tendency to melt also.

 

[POLAR_JEEP_04]

Usually when the resistor goes the fan works on High speed and nothing else.

I would check fuses first, connections second, then put 12v to the blower and see what happens. The resistor connectors have a tendency to melt also.

this.

 

[PacificEd]

As a partial follow-up for the issue, we have located the problem area which is the plug under the dash by the glove box. Wiggling the plug will cause the blower motor to start and stop.

When we find and fix the actual fault, I'll post up.