Heater - A/C Fan Control Switch & 4 WD Problem

[tingham]

Our '94 S-10 Blazer is freezing us out! This past summer there were times when the A/C fan wouldn't work, then suddenly and without warning, it would startup and work just fine. Now that COLD weather is here, and believe me I'm talkin' COLD to the bone, that switch, which also runs the heater fan, DOESN'T work at ALL! The heater itself works great, we can feel heat on our almost frozen toes, but no blower motor, and of course no windshield defrost either! We replaced the heater core this summer THEN noticed that the blower motor wasn't working all the time. I don't remember if we had trouble with it before the core replacement. We HAVE since replaced the switch in the control panel to no avail. Just last week replaced the blower motor itself, PRAYING that would fix the problem. So, relatively brand new switch and now brand new, NOT rebuilt or used, blower motor and STILL NOTHING! Fuses have also been checked. We're wondering if there's a fusible link somewhere for that blower motor. And we're praying it's NOT a bad wire somewhere. ANY ideas at this point would be welcome. December in Iowa is absolutely NO fun without a heater fan!

AND our second problem, the 4 WD is STUCK in 4 WD HIGH! We had some pretty serious snow in the past 2 weeks and used it a couple days ago. Now we can't get it to shut off. We had one mechanic tell us it could be the actuator (sp?)? $80 (for the part), that we really don't have right now, so am also wondering if it could be something else? Like maybe just the switch is bad? It too has kinda' been an on again, off again problem throughout the summer months. HELP PLEASE!

[Inze]

I have a 1996 s10 and I don't know if yours is the same set up but look into replacing the blower relay it is located under the hood on the firewall on mine. You can tell that the thing is blown cause it smells when you pop the top off of it and on mine it looked like it melted. It cost me 24 dollars and you have to go to a really good auto parts supply cause alot of places didn't have one. This should fix your problem but beware it temporarily fixed mine but then the relay blew again so it could be something else that causes this relay to blow but give it a shot. Im still trying to find out whats causing mine to blow, I heard it could be a bad ground somewhere??

[BlazerLT]

You have a vacuum leak.

[Inze]

Originally Posted by BlazerLT

You have a vacuum leak.

I have a vacum leak? Please tell me? This makes my blower relay blow?

[BlazerLT]

My bad, did you replace the resistor pack that controls the fan?

Did you replace the fan relay?

[Mikado14]

Originally Posted by tingham

Our '94 S-10 Blazer is freezing us out! This past summer there were times when the A/C fan wouldn't work, then suddenly and without warning, it would startup and work just fine. Now that COLD weather is here, and believe me I'm talkin' COLD to the bone, that switch, which also runs the heater fan, DOESN'T work at ALL! The heater itself works great, we can feel heat on our almost frozen toes, but no blower motor, and of course no windshield defrost either! We replaced the heater core this summer THEN noticed that the blower motor wasn't working all the time. I don't remember if we had trouble with it before the core replacement. We HAVE since replaced the switch in the control panel to no avail. Just last week replaced the blower motor itself, PRAYING that would fix the problem. So, relatively brand new switch and now brand new, NOT rebuilt or used, blower motor and STILL NOTHING! Fuses have also been checked. We're wondering if there's a fusible link somewhere for that blower motor. And we're praying it's NOT a bad wire somewhere. ANY ideas at this point would be welcome. December in Iowa is absolutely NO fun without a heater fan!

AND our second problem, the 4 WD is STUCK in 4 WD HIGH! We had some pretty serious snow in the past 2 weeks and used it a couple days ago. Now we can't get it to shut off. We had one mechanic tell us it could be the actuator (sp?)? $80 (for the part), that we really don't have right now, so am also wondering if it could be something else? Like maybe just the switch is bad? It too has kinda' been an on again, off again problem throughout the summer months. HELP PLEASE!

Check your fan switch, they are well known for going bad.

[BlazerLT]

He said he replaced the fan switch.

I'm thinking resistor pack or the blower relays.

[Mikado14]

Originally Posted by BlazerLT

He said he replaced the fan switch.

I'm thinking resistor pack or the blower relays.

LT, looks like we're breaking the trend. He said relatively. These cheapo plastic switches melt down and the contacts will pit. They are designed right at the edge of the envelope. A little too much current and they go.

[BlazerLT]

Ah, I wasn't trying to start anything, just stating what he said in case you missed it.

No attitude whatsoever.