The A/C-heater fan motor runs on the low setting, a little faster on the 2nd setting and shuts off on position 3 and 4. I don't have a wiring diagram yet, I I know, I know...

Any ideas?

 

When I got my car it had everything but High, and it was the relay on the firewall, not sure if that is your problem, but might want to check it out. Just a idea

 

Sounds like you could have a couple probs...

Check the blower resistor (in engine compartment by evaporator - it has 3-4 wires connected to it.) Remove it and look for damage.

Second, check the fuse holder connected to the big power stud on the horn relay. That is for high speed only. If okay, suspect the high speed relay (by brake booster.)

It could also be the switch in the dash, but I do not see them fail too often.

If the fuse is blown and the resistor burned open, the motor may be ready to die - pulling too much current.

Lastly, I see a chassis service manual on your parts list!

 

There are only three speed settings aren't there?
It sounds like the 30 amp inline fuse or a bad relay like Rob said. You should hear the relay click in when you switch to hi speed.
Check all the connections and grounds as usual.

Where's your CSM?

 

A/C blowers (in 72) have 4 speeds. Therefore my car does have a 4-speed!
Heater only blowers I think have only 3.

 

"I see" said the blind man.

I'll have to go see if my A/C equipped Vista has a 4 speed, can do some power shifting on the dash like in my Uncle Earl Scheib blue '64 Dodge spare-door.
The shifter buttons and park lever were a mirror image of the heater controls but on the left side of the steering column in my mighty 318 2 barrel equipped Dogdge.
I had the fastest shifting thumb in town and no other thumb could take me down.

 

Oh God........

 

...as he tripped on his hammer and saw...

My old Furd has a 4 on the floor and a 3 in the dash!

 

Thanks for info, I'll continue my troubleshooting and let you know what I find.


I have said 10 Hail Mary's, 5 Our Father's and a Glory Be. Oh, and ordered a "CSM"

 

I also have the same problem, my fan doesnt work on the highest setting. I changed the relay on the firewall and still no high. Does the resistor control the high setting also?

 

Nope, resistor is bypassed for high. Check the inline fuseholder for voltage on back towards the power distribution stud. Sometimes connections corrode and open up. Look for hacked wiring, too, from previous 'repairs'.

 

Well found the link today and it was apart with each end holding half of a broken fuse. Replaced the fuse and now my high spped work again. Thanks

 

Does anyone know what year they added the fuse and relay for the high speed fan to the electrical schematic?

My 68 has the parts, but the schematic in the electrical chapter of the CSM does not show the 30 A fuse or the relay. It shows the blower motor powered directly from the selector switch and a 25 A fuse in the fuse block. They must have changed this at some point, but didn't update the schematic? Maybe the 25 A fuse was blowing and/or the switch was failing.

My fuse looks OK, and I have a new relay, but no high speed fan yet. Need to troubleshoot.

 

I have never had that problem with my Cutlass, but every other GM car I have owned has a high blower relay. If that goes bad, you will only have the lower speeds, not the high. I assume Olds uses the same high blower relay, don't they? I think it's on the firewall (if I remember) on my Bonneville, and under the dash beside the ash tray in my pickup.

 

Would someone be so kind to identify where I can find the inline fuse?
Is it in an inclosed (taped) harness on the firewall or under the dash?
Not sure what I'm looking for.

Sounds like this is my problem - when I got the car it had several fuses blown and many light bulbs out.

Picture would be great.

 

The inline fuse would be between the horn relay junction block and the high speed relay right by the brake booster. What car you you have?

 

On my 68, the fuse holder is lying on top of the inner fender on the drivers side. Sort of bundled in with a bunch of wires.

 

I finally got back to working on my high speed fan problem. It appears that the fan switch is bad. I don't get 12 V from the switch in high position. It should be providing 12 V to the relay coil. I have A/C. Not sure who makes a replacement switch.

The 30 A fuse is good and the relay is new.

 

You might be able to carefully disassemble your switch and clean it up.
Be careful because it's easy to reverse the internal parts.

- Eric