The heater is not working?

SA0704CR

MEMBER
1999 CHEVROLET TAHOE
5.7L
V8
AUTOMATIC
2,241,547 MILES

I was trying to see if my vehicle had a filter but I researched that I didn’t, so I had to put the screws back from the compartment box underneath, but I didn’t remove anything else. I just removed the screws so I put everything back and I plugged in the two cables that I removed from the blower and a couple days later I use the Tahoe and the heater is not working I checked everything if there was any loose wires to be connected and there’s none what can I do?

Thursday, December 29th, 2022 AT 12:21 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,101 POSTS

Hi,

If that was all that was done, it could be a couple of simple things. First, make sure the two fuses are good and have power. See the attachments below. Note, when checking the fuses, it is important to also confirm there is power available to them.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Next, make sure the connectors are properly connected and not loose.

Also, at the blower motor connector, there is a black wire. Check to make sure it has continuity to ground. You may have pulled that wire by accident.

If the fan has stopped working at all speeds, then suspect either the ground has failed or both fuses have failed.

Let me know what you find.

Joe

See pics below. Note: For some reason, I don't have the fuse layout for the under-hood fuse box. It should be on the inside cover when you remove it. Look for Blower Fuse 3. It will be a 50 amp fuse.

Images (Click to make bigger)