Blower Motor only works on Med

[pound41]

Hello:
I bought this 71 blazer with A/C about a year ago. blower motor only worked on medium. I replaced the relay up by the kick panel it all worked great. This year goes back to only working on medium. I have replaced the relay again, blower motor and switch. Still no change. What else can it be.
Thanks

[MARKDTN]

Resistor pack.

[leddzepp]

Check the ground on the relay. I had the same problem you describe and that was the culprit.

[pound41]

I will check the ground on the relay
if it is the resistor pack where is it located
Thanks

[mrein3]

I bet the switch or the plug behind the switch is fried.

I converted my truck to AC. When doing that, I discovered that EVERY used blower motor switch I found in the junk yard was not working and the plastic plug that plugs in the back of the switch was melted. I ordered a new switch, new plug, and ran all new wires with the correct color and gauge according to the wiring diagram.

That was about 10 years ago.

Fast forward to last winter. My blower didn't work on one or two speeds. Sure enough my brand new plastic plug was fried. Again. And it took the switch out. Again.

I was in a hurry so I ordered a couple of new switches and a couple new plugs, replaced them, and put on my list of things to do "find orange, yellow, light blue, and brown wire in 12 gauge."

Stock wire is 14 gauge. Obviously it isn't beefy enough.

Anybody know where I can find light blue stranded 12 gauge wire? The other three colors are easy to find.

[MARKDTN]

Originally Posted by pound41

I will check the ground on the relay
if it is the resistor pack where is it located
Thanks

http://67-72chevytrucks.com/vboard/s...d.php?t=532916