72 blazer fan speed help!!
 

Hey guys, long time reader first time poster,

OK, so my 1972 Blazer w/ AC is having a problem with the hi speed on the blower fan turning on, low and medium work, i checked the ground and changed the switch with the same resoult, I tryed swithing out the little 5 prong box (relay i think) with a new one and nothing worked (hi low and med), thinking I got a dud From ACDelco I went back and got another one, same resoult, Is there some thing else that i should check? Any advice is much appreciated...

Re: 72 blazer fan speed help!!
 

Seems like high is fused seperate from low/med. Look under the dash for an inline fuse. Sorry...this is all from memory. I've gone through this before. But it's been a
while.

Re: 72 blazer fan speed help!!
 

Don't know what relay you replaced. But the relay that comtrols high speed only on the fan Is up by the top of the right kick panel. If that's not the one you were playing with, then it's probably your problem.

Re: 72 blazer fan speed help!!
 

Yeah a in-line fuse would make sence, I'll do dome looking, the last owner taped over all the wires heavly so If any one knows where to look let me know... and yeah its called the Hi-low relay, (the one I replaced) just went again (since i posted this) and got a new one again third time thinking the dealer i got the first two from got a bad batch, same resoult... nothing works... I'll keep trying new things thanks for the imput, if anyone else has some ideas please let me know....

Re: 72 blazer fan speed help!!
 

Wait sorry i might have mis-read your post, so there is two regulators one for low and med and one for hi??

Re: 72 blazer fan speed help!!
 

Don't know about a low med relay. But I've had a couple of the high speed go out, and the relay is above the right kick pad. A little hard to get at. And when it goes low & med speeds work ok. But high speed is dead.

Re: 72 blazer fan speed help!!
 

I had one where it would go to high only if you really slammed it hard into position, nothing more than a lever adjustment as it turned out.

If not that, then replace the unit on top of the heater box, it's hiding behind/beneath the glove box.