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Blower, Cruise, & various electrical gremlins


Blutarski
05-28-2009, 07:09 PM
I've got a 98 Blazer w/ a 4.3 and auto trans...

this all happened around the same time, but it's not my primary vehicle so the timing of the onset may be off. I discover these issues when I take it on a roadtrip and she says, "oh yeah, by the way..." Anyway...

The blower motor doesn't work, looked at the hvac2 fuse, which was blown so I replaced that and turned the fan switch up all the way and the lights dim a little like the blower should work, but no love. It didn't instantly blow the fuse but I assumed resistor or maybe even the motor and figured I'll check it when we got home.
A few miles down the road, set the cruise, and it won't work. So I pulled over and checked that fuse, toast. I replaced that fuse and it blows right away - No matter what the cruise switch position. I added this to the list and kept driving. Noticed that the high beam indicator light also doesn't work. No big deal... maybe related?
An old problem with this vehicle continued as well - the light sensor will click like the headlights should be coming on, but the dash lights go out and the marker lights don't come on with the headlights. All is fine if you turn the headlight switch to on. No sure if relevent, but thought I'd mention.
The plot thickens -
I checked the fuse for the cruise today, it didn't blow right away, but the high beam light was on(no matter what the light setting) and the blower worked. Then the fuse blew again. I tossed another fuse through the cruise setting and it blew right away but the blower started for a sec. The high beam indicator no longer works.

Any help would be cool - this is beyond my level of guessing.

Rick Norwood
05-29-2009, 01:47 AM
This sounds like a Multi-Function Switch. A major portion of the vehicle's electric circuits pass through this switch inside of the steering column. Hi-beam, Cruise control, Turn signals, Ignition, everything goes through it.

Blutarski
06-05-2009, 07:50 PM
So the wife was driving home today and the cab filled with a burning wire smell - cool, huh? Some blackened wires in the multifunction switch, whose replacement arrived today!
Replaced the multi function switch, the high beam indicator worked again, which was cool. Turned the fan switch and the cruise fuse instantly blew, took the high beam indicator with it. I forgot to mention earlier that the locks are screwy too. You can hit the remote, the horn will sound, lights will do their thing, but no lock action. Plus the switch does nothing. This worked again with the new MFS, until the fan blew that fuse again!
WTF?!
Any help would be really appreciated!

Rick Norwood
06-08-2009, 04:26 PM
So the wife was driving home today and the cab filled with a burning wire smell - cool, huh? Some blackened wires in the multifunction switch, whose replacement arrived today!
Replaced the multi function switch, the high beam indicator worked again, which was cool. Turned the fan switch and the cruise fuse instantly blew, took the high beam indicator with it. I forgot to mention earlier that the locks are screwy too. You can hit the remote, the horn will sound, lights will do their thing, but no lock action. Plus the switch does nothing. This worked again with the new MFS, until the fan blew that fuse again!
WTF?!
Any help would be really appreciated!

If the fuses are blowing that fast, You have a dead short somewhere. Check for the obvious, coins in the cigarette lighter, bare wires grounding out etc. If all seemed well prior to the fan switch, you could unplug the fan and replace the fuse and see if that helps, I have had fans burn up in the past and cause fuses to blow.

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