Blower motor slows when braking...

[bowtiefreak]

Ok weird issue and I'd like to hear some feedback on where to start chasing.

This is my 1997 tahoe. When the blower motor is running, usually low speed and I hit the brakes I hear the fan speed change. This only happens when the truck is in motion it seems. It does not appear to do this when sitting still. Ideas? Battery is new and was doing it before then. Alternator has some years on it. I notice no other electrical current draining types of issues. Is this a motor or resistor problem?

So?

 

[SunlitComet]

can you get a voltage drop measurement on the fan connector?

 

[bowtiefreak]

I could try too. All I know now is it slows pretty good and then comes right back

 

[SunlitComet]

please try. need the data. this happens when slowing down so is this just coasting or when you press the brakes? aside from he ht383 in there the charging system and power distribution system is still relatively obs?

 

[bowtiefreak]

All is stockish other than drive train. It only happens when I hit the brakes, coasting does not do it. It is down right now getting ready for some exhaust things to happen so I have not touched in in a bit

 

[SunlitComet]

then i would suggest that the brake light system is drawing excessive current lately that may be sucking power from the rest of the system or a ground common to the two systems may be damaged by corrosion or looseness.

 

[moviewithnotitle]

Bowtiefreak, did you ever get this issue cleared up? If yes, what was the diagnosis?

 

[bowtiefreak]

Nope, never touched it. Truck hasn't moved in a while. It will be a spring project for me I think.

 

[SunlitComet]

how dare you make us wait that long!

 

[SunlitComet]

and this long so far!