Rear Defrost not working after Heated mirror DIY

[flash22]

4 hours ago, Derek.w said:

The two wires you are looking for have the same colour coding as your boot/rear door defrost screen.

Just adding from behind the door card its easier to fuse each door modifcation with a seperate fuse.

WHY ???

The factory wiring is in place up to the mirror connector on the door !!!

[mmisch]

2 minutes ago, flash22 said:

WHY ???

The factory wiring is in place up to the mirror connector on the door !!!

So IIRC, u tell me to cut the two wires, crimp the 2mm wire to a 5mm thick wire, add the heater mirror fuse back and done?

 

If I didn't know about the pre-wiring, my best option would be to run the wires to the back.

[flash22]

iirc the wire colours on the door are white with black stripe and green

you posted a picture of the correct pins see what wires go to them

 

[mmisch]

1 hour ago, flash22 said:

iirc the wire colours on the door are white with black stripe and green

you posted a picture of the correct pins see what wires go to them

 

It looks indeed as a green and white with black striping

I can verify it's getting power with a multimeter after I received the working heater switch/knob I bought

[mmisch]

Got the part today,  if i have time tomorrow I will remove my wiring first from the connector and then replace it with this one, and hopefully the rear  window will work again

[Mooly]

8 hours ago, mmisch said:

And I thought just setting my multimeter to Amp and measuring it at the fuse was okay.. (when its powered on)

It may not be representative of the current draw in cold weather when the mirror glass is cold. A PTC (positive temperature coefficient) type of element will draw more current when cold and less current when warm. This ensures rapid defrosting in cold weather, and sufficient clearing of mist in warm weather while minimising unnecessary use of power.

Measuring the resistance when the mirror is really cold (freezer) will show the worse case condition and let you calculate the required fuse value. 

 

[Derek.w]

Just as flash22 advises its easer this way plus if you want to save a few £ you can always use a mail femail plug set off, lets say a scraped washing machine.

Or Just use a terminal block of some type and splice into your door wiring harness.

I wood reccomend soldering the wires on after removing 15mm of insulation wraping your wire around this and stagger joint locations re insulate and go over with silicone sealent to make all joints waterproof.

[mmisch]

4 minutes ago, Derek.w said:

Just as flash22 advises its easer this way plus if you want to save a few £ you can always use a mail femail plug set off, lets say a scraped washing machine.

Or Just use a terminal block of some type and splice into your door wiring harness.

I wood reccomend soldering the wires on after removing 15mm of insulation wraping your wire around this and stagger joint locations re insulate and go over with silicone sealent to make all joints waterproof.

Yeah I think so too, but have to see how I do it and which is better, soldering or crimping with a heatshrink over it?

 

[Derek.w]

I woud solder this connection the only crimp connection without cutting the wires are scotch locks these are problematic over time.

Scotch locks I hate them but they are quick but not as reliable.

Heat shrinking you have a problem removing the pin from the toyota plug unless you have a special tool to carry this out.

You can split the heat shrinking tubing and slise it down over the wires with silicon underneath

then rotate and apply some down the cut tubing and its ends.

 

[mmisch]

No I dont know what scotch locks are.

With crimping I meant, cutting the wire from the harness, stripping it, putting the wire in a terminal, and the other end goes in my wire that is connected to the mirror.

Update; nvm, have to solder it, don't  have any wire terminals left, like the picture

 

Also, is there a ground location on the door? If there is I don't  have to cut the ground wire from the harness itself. 

[Guest]

11 hours ago, mmisch said:

No I dont know what scotch locks are.

Good, don't even think about it. I am of the same opinion as Derek about them!

[mmisch]

Just now, mrpj1 said:

Good, don't even think about it. I am of the same opinion as Derek about them!

I looked them up what they are and yes I do know about them (didn't knew the english name) but I've never used them. And never will, so there's that

[mmisch]

Update: one problem less to worry about

[flash22]

There is a ground bolt on the bottom of the A pillar just below the connectors

splice the wire into the ground wire on the door, they all go back to the same place anyway

 

[mmisch]

3 minutes ago, flash22 said:

There is a ground bolt on the bottom of the A pillar just below the connectors

splice the wire into the ground wire on the door, they all go back to the same place anyway

 

Isn't there one in the door itself? If not then i'm just going to use that ground wire inside the connector

[flash22]

no ground point on the door everything has a ground wire, some are common'd (joined together) in the door wiring loom

[mmisch]

Oh okay, then it's gonna be both wires from the harness

[mmisch]

Verified it, 12v on the green and white with black stripe wires when I have rear defrost on, and 0v when off. Exactly what I needed.

[mmisch]

Update 2:

Everything works, no blown switches or fuses (yet), I have finally soldered the 2 wires that go to the mirrors and it's warming up.

Have to do the passenger side aswell but that's for tomorrow I think, hence the "yet".

 

[Derek.w]

mmisch

Glad to hear you well on the way to sorting it out!.

[Derek.w]

Scotch locks its a method of joining a wire to a existing cable without cutting the cable or removing insulation it has a blade you press into the cable with pliers but over time lets say 5 years movment vibration and dampness all effect this connection until it fails to work electrically.

[mmisch]

18 minutes ago, Derek.w said:

Scotch locks its a method of joining a wire to a existing cable without cutting the cable or removing insulation it has a blade you press into the cable with pliers but over time lets say 5 years movment vibration and dampness all effect this connection until it fails to work electrically.

Luckily I've never bought/used those in the time i've been doing these kind of wiring jobs

[Derek.w]

Best to keep well away from them.

[mmisch]

Also, update 3 (final):

did the passenger side in 2 hours. Everything works great!

Finally this car has heated mirrors which IMHO should've been from the factory. This 100% will help in the rain and snow. Thank you everyone for the help. 

For the people who wanna do this and don't have heated mirrors, check if U have those 2 wires to your mirror connector, do the same steps as me, run wires to the mirror itself and done.

If u don't  have these wires, I think connecting it all the way back to the rear defroster and NOT like me connecting it to the switch would be the other solution. (Correct me if i'm wrong)

 

[flash22]

Follow the KISS principle, Keep It Simple Stupid

 

Even the most basic cars will have the wiring in place