98 01 Explorer defrost switch

[Upsidedownranger]

I have searched around and gotten some information, just not enough.
My truck is an 03 4x4 ranger 4.0l
I have swapped to the explorer radio bezel.
My question is can I use the rear defrost button from explorer to run my heated mirrors?
Using a 9V battery I can get the switch to light up. But no success in power in power out.
I have an explanation of wiring colors but, really don't know how this works.
Also could the fog light switch be used?
It looks like I can pop and swap the button caps

 

[RonD]

The buttons operate relays not the actual devices

The heaters in the mirrors have a full time ground so just need the 12v power to activate the heater part
Usually there is a timer circuit in vehicles that have rear window defrost or heated mirrors, for either
You can get timer relays that would be activated by a momentary button on the dash, and that would power the mirror heaters AND turn on a light in that button, and heaters and light would go off once timer expired
12v Timer relays are not expensive, $15 maybe

Fog light switch grounds the fog light relay, which closes and powers the fog lights

Its all done with relays

If you have the wiring diagram for the explorer defrost button you should see what relay it used to activate rear window heater

 

[Upsidedownranger]

Thanks, so the factory defrost button (98-01) can be used with a timer relay?
I do have that schematic.
Also do you know of a thread where someone has done this. There are a lot of threads that come close but no step by step.
Thanks again for the reply.

 

[RonD]

No, never read of that being done

Don't know anything about the Explorer button
You should be able to tell what it does by the wiring diagram
Is it wired directly to a relay or does it go to a Control Module like a GEM?

2003 Ranger used GEM to control all cab electrics, it had the timers and controlled relays, and would NOT have rear window defrost circuit of course
So you will probably have to build your own circuit using the contacts in the button

 

[Upsidedownranger]

Here is the switch and color wires.

 

[Upsidedownranger]

I found this from a thread. 98 and the Gem, so the colors wires are different.

 

[Upsidedownranger]

And this is a explanation of my wire colors

 

[Upsidedownranger]

If I am following you correctly my blue and orange should go to the relay. The purple and green should be spliced to the hot coming from the relay to the mirrors?

 

[RonD]

For the button
Yes, blue/orange wire grounds the timer relay, you need to supply the relay

Green/purple wire gets 12volts when relay closes, so yes, spliced to the mirror heater power wire, this lights up the bulb inside button

Red/black wire is for "dash lights", spliced to Rangers Blue/red wires used for back lighting climate control or instrument cluster lighting when main light switch is activated, dimmer controlled voltage

Black wire is grounded to vehicle

Button looks like its momentary contact activation to GEM, then GEM uses its internal timer circuit to activate the heater relay



A timer relay is best to use, heaters like these are not meant to be left on all the time
Relay needs to be 12volt activated and rated for 30amp load
You will use a 20amp fuse and wire that to Relays coil and Load terminals, both
When you press the button the momentary grounding of the relays coil will activate the relay and timer
That will close the load side of relay sending 12v to the heaters and light on the button
When timer expires relay will open and heaters and light will go off

You will need to look for a timer relay that fits your need
You want one that's adjustable from 1 to 60minutes

 

[Upsidedownranger]

Thanks for your help. I will get a relay and attempt this soon.