AC Blower Speed

[MUSCL GN]

AC blows great on high but nothing at med or low. I read some other posts yeah I did the search thanks buddy! ) and decided to put in new blower motor resistor, but sill nothing on low or medium. Is there a relay for the 2 low speeds if so what location? What would be the next thing to check out? Any positive help greatly appreciated.

 

[GN owner]

A/C Blower Electrical Diagram

Go to this link http://www.gnttype.org/techarea/images/wiring_images/ac_heater_blowerswitch.jpg at gnttype.org and look at the schematic. If all of the wiring is good then it pretty much looks like a bad contact on the blower relay based on the fact that you already replaced the resistor assy. The odds of the low and medium contacts on the dash A/C blower control switch going out at the same time is very slim. Hope that helps.

 

[cjerry]

Need readable GN wiring schematics

I've got the mirror image of your GN AC problem. My 87 GN's AC works on low and medium but does not work in the high position. If you learn of a 'fix' please email it to me and if I find a 'fix' i let you know.
Have you found any readable GM wiring schematics on the web? I've seen several but they're so miniature I can't read them.

 

[gsgns4me]

Here is the heater blower diagnostics from a 1987 service manual. I hope it helps you guys out. I think the heading at the top of the schematic is a typo in the manual.

 

[kirbdawg69]

well you guys are doing better than me, i dont have a blower at any speed. havn't really tried to troubleshoot it yet. Did some simple checks, fuse, replaced the relay and put straight power to the motor to see if it will work and it did. Dose anyone have any ideas before i start doing so crazy stuff to the car?

 

[cjerry]

GN AC Blower

My AC blower didn't work at all when switched to the HI position. I found a burned out two wire connector between the AC blower unit and the right side hood hindge. The small wire was connected OK inside the connector but the 12 ga. red wire was burned off inside the connector. This is the wire that powers the relay that is screwed to the side of blower assembly. This problem was really sneaky! The connector 'looked' perfect, the red wire went into the connector and the red wire came out. BUT, when I opened the connector and inspected the contacts I saw that there were none.

Disconnect the battery when working on this red wire its always hot. I cut the old two wire connector off and connected each of the wire sets with 40 Amp 'push together' connectors. Problem solved.

 

[SWOOOSH]

there is also a bunch of wirer's that plug in were the fire wall meets the fender by the antenna, and they plug in there before they go into the car. when my blower does not work i have to wiggle the wirer's there to get it to come on. it was a lose fitting plug that i Had to fix. i think this was for high speed only.not sure i havet had the isue for a long time now. just my .02:biggrin:

 

[cool 84]

Mine was the relay near the blower motor. I had no low or medium, but only high. The relay went to one position for high and another for low and medium. I opened it up and it was full of rust. Cleaned it out and it worked fine.

 

[jcawley3]

I've got the mirror image of your GN AC problem. My 87 GN's AC works on low and medium but does not work in the high position. If you learn of a 'fix' please email it to me and if I find a 'fix' i let you know.
Have you found any readable GM wiring schematics on the web? I've seen several but they're so miniature I can't read them.

+1

 

[49-blues]

Did you check your fuses?

 

[86Nick]

That diagram does show the High spped fan relay on it. This is the silver one that mounts on evap box in engine bay.