Installing Heated Mirrors On None Heated Mirrors Truck

Kolobok101 · February 23, 2010

Hi all, I have 1999 GMC extended cab Sierra 2500 I do snow plowing and I would like to know if I can install heated mirrors on my truck, I already bought one heated mirror and connection looks like is wired for heated mirrors but how do I turn them one do I need to do any additional wiring ? Any help would help.

Thanks

pwall · February 23, 2010

Welcome!

Your truck may or may not be wired for it. Check your mirror housing, the heater wire may just be there.

If so, plug it in and it should work fine. The heated mirrors would came on withe read-window defrost.

Kolobok101 · February 23, 2010

Welcome!
Your truck may or may not be wired for it. Check your mirror housing, the heater wire may just be there.

If so, plug it in and it should work fine. The heated mirrors would came on withe read-window defrost.

Kolobok101 · February 23, 2010

thanks, but my truck doesnt have rear defrost. The thing is that the old mirror i took out has only 4 wires but the new mirror that i bought has 5 wires and the connector from truck side has 5 wires, but the problem is where do i turn on heat for my mirrors???? maybe i have to run brand new switch for the heat or something.

Dooner · February 24, 2010

The heated mirror function works when you turn on your rear window defroster. If your truck isn't equipped with one, you're probably S.O.L. Not sure if you can wire it up to a switch like you say.

Zeetwentyfour · February 28, 2010

I'm interested in this as well. Someone must have replaced the stock mirrors on my truck with the heated ones but I have no rear defogger. If anyone knows if all the wiring is in place that would be awesome. I'll look into it myself as soon as I get some time.

nickvrebel · March 4, 2010

as stated in the first reply, the heated mirrors are activated with the rear defrost button. Since your truck doesn't have this option from the factory you can't turn it on.... you MIGHT be able to get a new climate control unit (where you control the a/c and heat) that does have the defrost button, if the wire is there for the mirror then it's probably present in the dash.... but you would be taking a chance on that. I would look in salvage yards/ ebay for a used control unit with defrost button.

joejudkins · March 11, 2012

I'm currently installing heated/ led signal/ power adjust tow mirrors on my 2000 K3500 classic. I don't have a defroster either, but nobody's "S.O.L." I'll be finishing up the wiring ( i hope) on these things tomorrow and i'll let you know what i come up with. You might check to see if your dash fuse box has provisions for a defroster, if so, you'd just need to run wires and add a fuse?? I don't know. Thinking of finding a source under the dash somewhere and splicing in an auxillary switch with a circuit timer or something. i'll let you know how as soon as mine are done. Is yours a '99 C/K-series or the '99 light 2500 with the 6.0 and the newer body style? wiring is probably similar, but might not be exactly the same

Doug_Scott · March 11, 2012

Can someone that does not have a rear defrost from factory, and having added heated mirrors, just press the heater mode control and see if the centre moves inward? Actually, can anyone that does not have heated mirrors and rear defrost, press the middle of the mode control knob and see if it moves.

Since rear defroster is an option, and heated mirrors are standard on the SL version of GMC, there must be a way of activating it on the SL when no rear defrost is ordered. Note that the W/T does not come with heated mirrors as standard equipment, and is not an option you can order the truck with.

Perhaps you can go to wreckers (as someone else mentioned) and get the mode control from the HVAC controls. If you have the auto climate control, they you also have heated mirrors stock. Every model above the W/T comes with heated mirrors, regardless of whether it has rear defrost or not.

joejudkins · March 12, 2012

Okay... I got it. To maybe answer some questions... on my 2000 C/K, if there isn't a defroster and or factory heated mirrors, there is no provisional wiring for either (would have been nice though). I extended the wires for the heater through the doors and the kick plates. connected the wires and ran a lead to a toggle switch ($4 at Checker/ O'reilly), found a constant power to connect to the switch (positive wire from a cigarette lighter), and then ran a ground wire from the switch to the floorboard. sounds simple enough, but it took me most of the day to run these wires and get the dash back together. Hope this helps

Doug_Scott · March 12, 2012

Okay... I got it. To maybe answer some questions... on my 2000 C/K, if there isn't a defroster and or factory heated mirrors, there is no provisional wiring for either (would have been nice though). I extended the wires for the heater through the doors and the kick plates. connected the wires and ran a lead to a toggle switch ($4 at Checker/ O'reilly), found a constant power to connect to the switch (positive wire from a cigarette lighter), and then ran a ground wire from the switch to the floorboard. sounds simple enough, but it took me most of the day to run these wires and get the dash back together. Hope this helps

The positive wire from the cigarette lighter is live all the time isn't it? What are the chances of forgetting to turn it off, and coming back to a dead battery?

You could have picked up a fog light relay from your local auto store, and use the same feed wire you are using now, and then locate a wire that has power to it when ign is on, put your switch on that wire and connect it to the relay. This way, you cannot turn the heater on until ign is on, and when you turn the truck off, the relay will open, and no dead battery.

Relays are handy little things for stuff like this.