shoptek

I noticed that the blower motor does not work on high speed recently.
The in line fuse on the left fenderwall is fine, and there is 12 volts on that line.
All other speeds work fine.
Any other suggestions??

CDaniel525

Ive always had something similiar to that....hi speed wouldnt work if i clicked itt over to that speed real quick, but if i do it slowly it fine. It could be the blower relay, but mine has done it since i got a brand new one when i fixed the whole system

good luck
Chris

rhoeven

Don't know a '71 but I assume it is same as my '81.
The problem seems to be the high speed blower relais. With the blower switch in high position, the coil of the HS blower relais gets power, the relais energizes and its contact switches the blower motor directly to +12Volt via fusible link from starter solenoid.

Hope this helps

Roger

MotorHead

Check the plug inside the engine compartment near firewall on passenger side
Should have about five or six wires one for each speed and ground and power, possibly the tang for the high speed is broken off.

bluevette

I'm not much of an expert on this. But I believe the "High" position runs separate from the rest of the settings. Let me explain. My blower motor had been going bad for some time and would make an awful noise while running. Someone told me about the plug that Motorhead mentioned, so I unplugged it. Then all the settings quit working when I unplugged, except for the "High" setting. It still worked. Don't know what controls the High setting, but it isn't that plug. Good luck.

John

Guest

On my 77 there is a high speed blower relay on the engine side firewall above the right side of the ac heater box. A plug will be going into the bottom of the relay. Pull the plug and clean it or in my case it just works loose and I push it back in and the high speed starts working again. The low and medium speeds are the wires going into the top of the ac heater box. Chuck

Larry B.

Marc... It is the blower relay that is bad. It is the little relay on or on top of the A/C housing (on passenger side) in the engine compartment. :yesnod:

mrvette

I recommend moving the high speed relay from the a/c box just above the passenger's header/manifold....and mount on top of the a/c box, very carefully as the condensor is in there....rewire as necessary, the thing suffers from too much heat....burnt wires, etc...corrosion...

GENE

C.T.

Marc....Had the same problem on my '72. The contacts inside the relay can build up a carbon deposit over time and could just need a simple cleaning. Remove the relay from the car and carefully remove its' cover by straightening two of the bent-over tabs. Use care to not break either of the fine-copper wires on either side of the relay once you have the cover off. You'll see the contacts that come together when the relay is energized. I used a very small piece of 600 wet/dry sandpaper to clean the contacts followed by a gentle cleaning with isopropyl alcohol on a Q-tip. Re-assemble and reinstall. Best wishes!

Smokehouse69

Marc,
C.T. hit the nail right on the head, follow the advice and your blower should spin up to max speed.

shoptek

Thank you all!!!

It turned out to be the connector on the relay, which was SHOT. I cleaned the terminals, replaced the plastic connector housing, cleaned the insides of the relay and it now works.

Pete79L82

Thanks for letting us know what fixed the problem. So many times members get advice on how to fix a problem but we never find out what actually fixed it. Thanks for the info!