? Short question: Added factory heated mirrors, how do i make heat function work ?

08 xl manual climate control

longer version with more background:

2008 xl that was originally equipped with basic mirrors that only adjusted by power, but no heat or lights of any kind. I previously added new/used side mirrors from a 09-14
that had puddle lights, turn signal and heat. All those features (besides heat) worked plug and play, no mods required.

When my fan switch went bad, I happened to get a replacement that also has defrost button/switch. The button illuminates while pressed, but not when released (assuming b/c nothing connected on circuit). I’m now interested in trying to make the heated mirror function work.

?is the defrost button on switch panel what activates mirror heat (see pic)?

?I think I need to add a defrost relay, where is the plug/harness located (where would I plug in the relay)?

?any other tips/suggestions ?




Replacement switch panel, that has defrost button.

 

I believe, for this gen, it’s the rear defrost button that also controls the mirror heat.

If you don’t have rear defrost, I think you’ll have the wiring for it.

Also, power mirrors on an XL from this gen are rare. XL’s of this generation were normally manual windows, locks, mirrors, etc. yours must have been a custom or fleet order.

 

my xl came (originally) with pw/pl, a/c, and cruise control. And, orig mirror were power adjustable (but no lighting/signals or fold).

? Do you know where the defroster relay is located, so I can look to see if I have the port/plug/place to add/plug in relay ?

 

I don’t, unfortunately.

 

Relay #4 in the cjb is the rear window relay, and then it would run from there through fuse #8 to the mirrors per the 05 wiring diagram manual.

 

thanks for this post. I thought that the relay was located outside of junction box somewhere (ie like I think powerfold is). But now see what you’ve referenced.

looks like there is also a 40amp fuse #114 for defrost/mirrors too.

I am not at truck now, but will check it out later and post back. Hopefully it will be as simple as needing to add the relay and/or fuses. Thanks again for taking time to post.

 

Just looked. 114 fuse and relay are both missing/open in my cjb, hoping adding them will enable heat in mirrors.



https://www.startmycar.com/ford/f-150/info/fusebox/2008

 

Attempted to install fuse and relay. Fuse inserted normally. Relay is super loose, doesn’t make normal connection. I’m assuming that the CJB for my xl didn’t have this circuit/socket set up for r04.

? Does this sound right that it isn’t setup to accept r04 ?

I have a spare 08 king ranch CJB (bought when troubleshooting KR):

- any potential pitfalls by trying to swap in the KR CJB?

- would doing so likely enable heat for mirrors?

thanks.

 

. . .

 

Hoping someone can provide feedback on whether swapping CJB is a good or bad ideA? Or any other suggestions for next steps ?


@needsmoarturbo
@2008__XL