ae86 rear window demist/defrost

[d-86]

hey
wondering if anyone knows anything about the rear window defrost.
How it works and all.
Currently my one doesnt, and with the weather cant really see.
So any one have idea on how to check what the problem might be.
Cheers

[hairywally]

i have a problem with mine, but i know mine is the switch. i'd try that first as it is the easiet thing to change.

does the little orange light come on at all?

[d-86]

yeh the main switch light comes up
im thinkin its the connection to the rear window
but how is it connected?

[oldcorollas]

assuming the d doesn't mean drift

well.. it's conected by wire somewhere, and it should be relatively obvious. look at the defroster stuck on the window and see wher it leaves the window. there should be two spots with wire (do they go thru the top of the hatch?)

get your multimeter and check you have voltage between those connections and ground when the thing is turned on...
and also check the resistancve between the two wire connections to make sure the defroster stuff ont he window is still healthy.

good luck

[Mos]

Heya,
There should be two male spade terminals soldered to pads on sides of the heater grid. Two female spade plugs sit on those terminals and disappear into the pillars of the hatch. One of them is grounded under the trim of the hatch and the other is plugged through to the loom that runs back up the pillar and to the roof.

As Stew said, there should be power across those two points when the demister is turned on - check voltage across the points (should be 10-14V), and check with the multimeter positive lead on each point in turn with the negative lead somewhere on the chassis (should get 10-14V on one side, and 0-1V on the other - if both of these are 12V you have a grounding problem on the ground side, if both are at 0V you have a power supply problem somewhere between the swtich and the glass).

(Once again) As stew said, check resistance across the two points with the demister witch OFF - you should get some low resistance, perhaps 1 Ohm.

HTH.
Mos.

[LeeRoy]

My corolla had the same issue and it turned out to be someone had removed the rear tint with a ravor blade and destroyed almost all of the demister bars running across the window.

- LeeRoy