heated mirrors, 2010 fj cruiser

Hi Everibody, i'm a bit of a retard when it comes to electrical stuff. I will be installing heated mirrors on my 2010 FJ cruiser. The plan is to hook them up to the rear defog button for simplicity. Assuming that i will find the right wire that goes to rear window defogger and tap into it 1.) will i need to add an inline fuse between the point of tap and the heating pad? 2.) Where do i ground the heat pads? Thanks!

Use a SPDT 30/40A relay to isolate the circuit at the defrost switch from the heated pads. Use a inline fuse from the power source at the relay to the heated pads (fuse according to the heated pads current consumption). Trigger must be a timed output otherwise the pads will only engage when the button is depressed. If negative trigger at switch: 86: 12v (fused) 85: (-) trigger from defrost switch 87: 12v (fused- you can tie 86 & 87 together) 87a: Not Used 30: positive lead at headed pad If positive trigger at switch: 86: (+) at switch 85: Ground 87: 12v 87a: Not Used 30: positive lead at headed pad Make sure you ground the pads to bare metal/chassis.I drink current, eat ohms, and bleed voltage

Here is the factory wiring diagram, The yellow/purple wire leaving the defogger switch and going to the defogger relay is your low power negative wire. It is located in a blue connector in the drivers kick panel. The output of the relay is YELLOW /GREEN and Positive. It is located running down the drivers side floor harness(under the drivers door sill plate)

wow thanks guys. pts760 before last night relays looked like nuclear physics to me, but a simple google search proved it otherwise, now its all good and clear and I am of a strong opinion that the relays are the way to go. However some folks on fjcruiserforums.com wired them directly to the positive trigger without any relays claiming that heat pads do not draw too much current. flobee4 thanks. Yes I've done some research and found out that YELLOW /GREEN wire needs to be tapped in. Should i try to solder or Posi Tap will do the job?

solder only its actually yellow/purple in the driver kick panel (-) 8min latched blue 18pin plugTed

2nd Year Tier 1 Medical School

Still installing as a hobby...pays for groceries

Compustar Expert

Since i've opened this topic, i found another write up on heated mirrors on Tacoma and the guy used the OEM Mirror heater button, so i guess I will try to go that way instead of tying mirrors to rear defog. Here's the link for the writeup. it does seems more complex, but the end result is just so much better. Tacoma Heated Mirrors

Nice write up. I would skip all those "quick splice" connectors though. Just solder and heat shrink those connections instead. Especially because all those wires shown that used a "quick splice" were wires added for the project. And while you are soldering those connections, might as well skip the butt-connectors too.

yeah, planning on soldering connections instead of t-taps and quick splices. this brings me to my next dilemma, obviously since the car is outside and i dont have a garage i will need a cordless soldering iron. should i get Weller butane one or battery powered ones? It seems to me batteries will be dying very soon and with butane one i could also shrink the heatshrinks.

battery irons are not that great. The butane one works very well, as long as you don't place it on the carpet by accident. I used to use the weller pyropen/pyropen JR, but changed to a MAC tools one since it was much cheaper to buy. if you don't solder often, get a 20 dollar wired one, and use an extension cordTed

2nd Year Tier 1 Medical School

Still installing as a hobby...pays for groceries

Compustar Expert

I have this fetish for tools to be honest and try to buy tools whenever I can justify their purchase to wife :D So i'm just putting an order thru for Weller PSI100k and other bits I will need for the install.