The "high" setting does not work with either the heat or the a/c on my '71 cutlass. The lower settings function normally, it is just high that does not work. I currently do not have a belt attached to my a/c compressor/clutch under the hood because it is locked up and I am still waiting on the replacement. But that should not affect the heat.


I have checked the fuses and the wiring under the dash, and everything there is as it should be. Does anyone have any ideas?

 

It's either the hi blower relay or the inline fuse that goes between the junction block and the hi blower relay.

 

Thanks. I hate to sound like an idiot but is the "Hi" blower relay different than a standard blower motor relay? It's just that I've never heard of that one before.

 

They're located in your Chassis Service Manual, on page 1C-7, fig. 1C-10, and page 1C-15, fig. 1C-20A.

- Eric

 

I don't have the chassis manual yet. I just looked online and they're $70 on Amazon. Have you seen them cheaper anywhere else?

 

I've had this problem on several cars & it's usually the fuse. The fuse is(was) located about 6" rearward of the horn relay on the driver fender. It is a black? wire with a bulbous fuse holder. It is suppose to gently pull apart but I've found usually the rubber has fused together. Try a small screw driver to pry it apart & inspect the fuse. It is a short guy & can be found at most auto parts stores.

 

I would strongly recommend getting one.

No, but I sincerely doubt that you can get an original manual on Amazon.
You don't want somebody's photocopied scan reprint. You want an actual manual.
I would try eBay, and keep watching for a while to see what comes up.

Also, for a roughly $25 one-year donation, you can download all the manuals you'd like from WildAboutCars.com.






- Eric

 

Thanks for the info. I'll have keep my eyes open for a printed copy.

 

I have the same problem with a 70 cutlass. I tried a new relay. No difference. Quite a few people believe it's the inline 30 a fuse. I have not checked the fuse yet, but do know that I am getting 12 v to the relay. I hope it is with a fuse, for that the next step is a heater switch. If you find out what fixes yours, let me know. Thanks

 

I'll let you know. I couldn't get to work on her this past weekend (too much yard stuff to do). And after spending most of Saturday in 90+ heat and humidity working on my yard and helping the neighbor build some new doors for his shed, I just did not have the energy.

 

I have same problem on my 71 442. I have not even thought about tackling it because I really don't use either heat or ac much but I am interested in diagnosis and fix. I'll be watching this post.

 

Good news/bad news.


I finally got a chance to check on the fuse. When I unwrapped the electrical tape around it, the fuse completely disintegrated. Now I have another question.


The boot (attached to the wire) that runs to the high blower relay from the fuse...Does anyone know if that is actually part of the wire or is it just on it? Can it slide down the wire so that I can get to the metal clamp that hooks up to the fuse? The metal end of the broken fuse is stuck down in there and I do not want to break the wire (it is 44 years old after all) if I do not have to. I've tried a little penetrating oil to loosen it up, but so far, no joy.

 

I believe the boot is part of the wire. Try a small flat screw driver &/or small needle nose pliers to extricate the remains of the fuse from the holder. If you damage it, I or others on this site can supply an original harness, or your local parts store has generic fuse holders you can install in place of your original.

 

Bad news...the clamp in the boot fell apart also. I'll send you a private message.

 

Hey guys,

My car had the same issue and the former own put an aftermarket in line fuse in.

My question.
It's a 30 amp fuse correct?

 

Everything that I've heard and read says that a 30 amp is the right one.

 

I dunno. It's not like it's printed on the schematic I posted or anything.



- Eric

 

Doh!

 

 

Well Eric thanks for pointing that out.
What would we do without you!!

 

VICTORY!!!! well partially anyway.


While I am waiting for a possible replacement (thanks Scott aka oldspackrat) for keeping your eyes out trying to find one for me, I made my own wiring setup just to see if it was the fuse or the high blower relay. Darned if it did not work! Air (while still not cold) is once again blowing out of the vents. So for everyone out there that was having this problem too, a $2 package of 30 amp fuses beats a $40 blower relay any day of the week.


By the way, I am still looking for the original wiring for this. So if anyone lays their hands on one, send me a PM and I'll get back to you.