electrical/ac and heater blower switch help?

[debmc1958]

I have a '91 S-10 Blazer that I hope to get in running condition for my son who will get his permit at the end of the summer. My first project is the heater/ac blower which was the bane of this vehicle's existence for years. It works, doesn't work, etc. The blower has been replaced at least twice. I took the interior switchcover off (sorry I am not too up on auto lingo). The switch that controls the blower has 4 spots with clips and wires. One of the clips was obviously blown out and burnt. I bought a new one and put it on but it still doesn't work.

Is it necessary to disconnect the battery to work on something like this?

[89s10]

My favorite book to go by is chilton's they covery about every thing.Just take your time and you can do it .

Is it necessary? No. No power goes to the switch when the key is in the off position. It is smart to remove the negative battery post because anything can happen at any time. It is always better to be safe then sorry.

Do the kid a favor and buy him a Ford. LOL

[debmc1958]

Originally posted by Beefy's Bronco
Is it necessary? No. No power goes to the switch when the key is in the off position. It is smart to remove the negative battery post because anything can happen at any time. It is always better to be safe then sorry.

Do the kid a favor and buy him a Ford. LOL

I really don't need a shock, either from fixing the blower or from buying a Ford.

[justen]

I had that trouble with my 92 blazer I had, I replaced everything until I finally came across what was the problem, It was my relay switch, there are three relay switches on the drivers side fender, one is fuel pump, the second is heater and ac, and the third is windshield wipers, horn and something else can't remember, But anyways the relay would stick on or off and it would blow the heater switch out or in easier terms (kentucky fried) Try that and see, it's like 4 bucks at a auto parts dealer. To install it you need to push down on the relay with a plain screwdriver prying on the back tab then it will just pop out, then you can unplug harness too it and put the new one on.

[debmc1958]

I will check into that first. Thanks for the info.

Originally posted by justen
I had that trouble with my 92 blazer I had, I replaced everything until I finally came across what was the problem, It was my relay switch, there are three relay switches on the drivers side fender, one is fuel pump, the second is heater and ac, and the third is windshield wipers, horn and something else can't remember, But anyways the relay would stick on or off and it would blow the heater switch out or in easier terms (kentucky fried) Try that and see, it's like 4 bucks at a auto parts dealer. To install it you need to push down on the relay with a plain screwdriver prying on the back tab then it will just pop out, then you can unplug harness too it and put the new one on.

[rapideo]

That relay tends to get burned from the AC clutch beening switched off and on so much. On a Dodge its the same as the horn relay, they can be switched if needed to get heat or cool

[debmc1958]

hmmm Maybe I am seeing a pattern here. The horn also stopped working.