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heating problems...


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Hi all,

Ok, I have a 70 LeSabre that's giving me some crap...

The heater in the car works, but only on the "max" setting. Rather, the blower only works on that setting. Otherwise it doesn't work at all. What could this be? I'm thinking maybe the blower resistor, but I really don't know. Any help would be great. Thanks!


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I would check the relay. It is a small box about the size of a cigerrette box just not as long. It is usually located on or near the heater box. It will most likely have a T-shaped connector going to it. Check to see if it is getting power and take the cover off to see if the contacts are dirty. Sometimes you can just file corrosion off of the electrical parts.

Universal replacements are available, but they can often be fitted to the original relay case to keep up appearances.

Hope this helps


71 riv

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You might try tapping on the blower motor relay on the a/c case under the hood. Sometimes the contacts might stick of something. The blower motor resistor should be adjacent to the relay in the a/c case. All the fan speed switch does is change the circuit the power goes through on the way to the blower motor. Each circuit has a respective resistor coil that is mounted on the bakelite backing plate where the electric terminals plug onto it. Once you find the "power out" wire on the resistor, you can check continuity of it with a meter but by that time you could have removed the two or so screws holding in to the a/c case and done a visual inspection. If you have automatic a/c, things could be different, but these things should work for the more normal "manual" a/c system.

In some systems, the blower motor relay also serves as a "high blower relay", but if it's wired that way, it might work on lower speeds and not on high speed.

Those systems keep the higher current from going through the blower motor switch as such and thereby keep it from "cooking" during long periods it might be on high speed.

If the switch has an internal problem, it probably will have a more loose feel without the specific internal detents feeling as "tight" as they might have in the past.

It's a pretty straight forward circuit that should be reasonably easy to trace and trouble shoot.


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Thanks everyone for posting...

I figured it out last night at around 1 a.m. (I was bored and figured, hey, it would be nice to be able to adjust my heat, plus I put in new speakers laugh.gif )

Anyhow, it was the heater relay that was screwing me up. And by following the wiring diagram in the service manual...I was effectively confused. They put the relay in the car...but as NTX5467 pointed out, it's actually right smack between the blower and the a/c box. Well, the light blue wire was disconnected which is what caused it to only work on the high setting. My little connector is busted which is why the wire wasn't in the connector in the first place.

Thanks again for all the help anyway wink.gif

I love this forum!


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