Heater/ac blower issue

[Darrell]

Hey all, I have a my '95 and my heater/ac blower stopped blowing on the high speed only.

I've replaced the turn knob switch on the dash panel with a new one and I'm getting the same results. It blows perfect on Lo and the (2) intermediate speeds but not Hi

This leaves me thinking.. Could it be the blower resistor above the glove box region ? But I thought that a bad resistor simply meant that it wouldn't blow at all. Am I wrong.. Which I wifey says all the time..haha ?

Thanks all

 

[Eveready]

Usually the blower motor resistor gives a problem on the lower speeds. For it not to work on high my suspicion would be the blower switch itself. I have heard that the connections at the switch tend to go bad and heat up causing the switch to go bad. My suggestion would be to test the switch first by jumping hot directly to the blower motor. If it runs at top speed you have your answer. Sometimes just pulling the controller and cleaning up the connections will fix it and otherwise you are looking at replacing the control for the HVAC.

Let us know what you find.

 

[Darrell]

That was my thinking as well that a bad resistor was seen at the lower speeds. Since I replaced the switch already with a new one and the problems the same, I leaning toward a new panel....ugh ! I replaced the panel back in 2016 when this very same problem occurred and that fixed it. I was hoping it was a cheaper fix this time as in a switch or resistor instead of another panel. The cheapest panel thus far on amazon at $185...yikes, in 2016 I found the same for $93

 

[Schurkey]

I don't have a wiring diagram suitable for that vehicle...but...I'd expect either a high speed blower relay, or a high-speed blower fuse.

The vehicles I'm familiar with use the resistor pack for all the lower speeds--depending on what goes bad, you lose one or all of the lower speeds.

High speed doesn't go through the blower resistor assembly. It's run via a separate, in-line fuse or via a relay.

But your vehicle could be different. A wiring diagram would help immensely.

 

[east302]

Here is the diagram for a 98. I’d suspect that the 95 is the same setup. The high-speed blower relay is, on mine, adjacent to the blower resistor. Hope this helps.

You must be registered for see images attach

You must be registered for see images attach

Sent from my iPhone using Tapatalk

 

[Eveready]

If you didn't replace the relay before and the new switch fixed it for a time, then it could be the relay and it also could be your connection to the switch gone bad. I would definitely look there first which would start with the cheapest fix and proceed from there.

Sometimes the connection can look good and still not be making good contact.

 

[Darrell]

Honestly I didn't even know there was a blower relay..I guess I should of looked more in-depth.

And that was the problem. Removed the glove box cover, and replaced with 2 min... Fixed !

Thanks again all for the diagram and suggestions

 

[Schurkey]

So the NEXT question is "Why did the high-speed blower relay fail".

It could have failed randomly--it was "just it's time".

It could have failed because the blower motor is drawing too much current. Fairly common to have dry bushings, low RPM and high current draw from a failing (but not totally failed) blower motor. Does the motor ever squeal on start-up? Do you have an ammeter that will measure <10 amps (probably around 5)? You could tap into the blower high-speed circuit or just jump it direct from the battery and measure current draw.