Rear defrost power?

[Mike Phelps]

I looked at fuse 30 and it’s fine. No indicator light on the dash for the switch and no rear defrost. Where else do I look?
2002 KJ

 

[LibertyTC]

It could be the switch itself, however there also is a defogger relay..see image of the schematic diagram.
Rock auto shows relay here: https://www.rockauto.com/en/catalog...itch+&+relay,rear+window+defroster+relay,3432
Hope this helps, The 2002 factory service manual is very useful! http://www.colorado4wheel.com/manuals/Jeep/KJ/2002JeepKJServiceManual.pdf

 

[Mike Phelps]

It could be the switch itself, however there also is a defogger relay..see image of the schematic diagram.
Rock auto shows relay here: https://www.rockauto.com/en/catalog...itch+&+relay,rear+window+defroster+relay,3432
Hope this helps, The 2002 factory service manual is very useful! http://www.colorado4wheel.com/manuals/Jeep/KJ/2002JeepKJServiceManual.pdf

Thank you, I’ll dig thru the manual.
Where is the relay, under the hood?

 

[LibertyTC]

This particular relay does not have easy access as far as I know, & never have I had to open/access the Junction Block.
Junction Block is located underneath the driver's side of the dashboard to the left of pedals.
Start at switch and understand testing. I hope Bill our electronic specialist may chime in on this one.
You need to read the FSM see section 8G onward. You will find info about the interior "junction block" & also info about the de-fogger relay location.
Yes u will probably have to remove the lower shroud /knee bolster panel ++ & +.

 

[Billwill]

I will have a better look into your problem but On the rear side of the interior Fuse Panel there are some Circuit Breakers as shown in 95.jpg above.

I am sure one is for the rear widow heater element...although this is not shown... one I believe is for power seats and the third I think is spare.

Check that Breaker first and check if you get +12 volts on the rear demister.

Swap over the Demister Relay with a similar one nearby.

If the Breaker keeps tripping then you have wiring problem going to the element!

The connectors onto the rear Demister Element can give problems and the element itself can have a break in it!

I will look further into the Wiring Diagrams to see if I am correct as regards those Circuit Breakers!

Section 8W has all the wiring diagrams and I cannot find what all those Circuit Breakers do so I am probably wrong...Read Section 8Q well as it describes how the rear demister works and how to fix a broken element etc.

My 2002 is an Export CRD so there may have been some changes made!

I have only been wrong once before...I thought I had made a mistake but I actually had not!