2006 Impala rear window defogger problem

Turned on and switch light comes on but no defogging on ear window
Checked relay in the fuse/hood box and looks okay – I can hear it click on on/off
Checked two connections to defogger grid – positive and negative and both appear to be okay. Good continuity from negative side to ground
With switch is on, I checked the voltage and it reads 10 volts across positive and negative connectors when the connectors are disconnected. When they are connected, the voltage across the terminals reads zero.
No disconnects in the grid are evident.
Is this a switch issue? There appears to be reasonable continuity across the grid but when the connector are hooked up the voltage drop to 0 volts (positive to negative side)

Am I missing something here?

2006 Impala rear window defogger problem

Turned on and switch light comes on but no defogging on ear window
Checked relay in the fuse/hood box and looks okay – I can hear it click on on/off
Am I missing something here?


follow the ground wire to the body ground and check for a good connection....OR with a solid connection to the body jump the ground side connection to the grid...see it the voltage stays around 10-12 volts across the grid..

with a large amount of current demand by the heat grid the voltage drop may be due to a poor ground..

2006 Impala rear window defogger problem

Turned on and switch light comes on but no defogging on ear window
Checked relay in the fuse/hood box and looks okay – I can hear it click on on/off
Checked two connections to defogger grid – positive and negative and both appear to be okay. Good continuity from negative side to ground
With switch is on, I checked the voltage and it reads 10 volts across positive and negative connectors when the connectors are disconnected. When they are connected, the voltage across the terminals reads zero.
No disconnects in the grid are evident.
Is this a switch issue? There appears to be reasonable continuity across the grid but when the connector are hooked up the voltage drop to 0 volts (positive to negative side)

Am I missing something here?

I have the same problem -- did you find a solution??

Hello -- I am having the same problem and test findings - Did you ever solve the problem??

Hello -- I am having the same problem and test findings - Did you ever solve the problem??

follow my instructions in the earlier posting....bad body ground...is common..

The Ground is good - checked it and cleaned it and reconnected - I fed raw battery to the rear defogger and it worked ok. I am now assuming a poor connection in the power feed??? I would assume this is a major job to track down.

The Ground is good - checked it and cleaned it and reconnected - I fed raw battery to the rear defogger and it worked ok. I am now assuming a poor connection in the power feed??? I would assume this is a major job to track down.

not really ..make sure the fuse holder is ok...some have found defective loose fuse connections..this heater is a very high current circuit...if the fuse has full voltage on both sides, then I would remove switch check connections to switch if ok replace switch/or measure at switch to see if voltage drops at the switch..