AC/Heater Cabin Fan quit.....

[DieselDavy]

'97 2door tahoe,
Lost "High" setting last year, didn't worry about it.
Last week lost 1, 2, 3 speeds, so no fan!!
AC kicks in when button is pushed, just now fan!
Checked fuses, looks good.
I'm thinking I need to check the fan motor itself.
What say ye?

Thanks,
Dave

[DmaxMaverick]

Replace the resistor module. You'll get all your fan speeds back.

[JohnC]

Check the fuses, too. I think there's one for high and another smaller one for the other 3 speeds. If they're both blown it could mean the motor is heading south.

[ronniejoe]

There's a connector in the harness near the blower motor that is notorious for over heating and melting. I've repaired it twice on my truck. Occasionally, the fan will quit and I have to wiggle the harness to get it going again.

On my wife's 99 Tahoe, similar symptoms were caused by a overheated connector on the fan switch in the dash.

The resistor module could be the problem, but I would check these things as well.

I don't know why GM seems to under design the wiring in their vehicles.:rolleyes:

[DieselDavy]

Great advice guys. I've checked the fuses and relays.

Ronniejoe, Bingo! The switch head was melted badly along with it's connector on the wiring harness. I'll check the current of the fan but I think higher resistance than intended in the connector (hence great heat) did the damage!

Thanks guys!

Dave

[ronniejoe]

I think the switch and connector are marginal when new in good condition. Any corrosion or degradation over time leads to the increase in resistance and the excessive heat.

It might be a good idea to put some dielectric grease on the connections when you replace the switch and connector.;)

[JohnC]

Those fans draw a ton of current on high.