Defroster
 

Looking for hints on fixing the rear window defroster. I had a short circuit or something and I think that the cables burned but not sure. I don't really use it that much down here in Puerto Rico but it would be good to have it if I need it. Any suggestions besides going to an "electromechanic"? I heard that it could cost me an arm and a leg to get it checked out by my local Mazda dealer.

i've had a problem with the defogger in both my pros. in both cases it was the shitty switch - it has copper connectors inside and they are really weak.
first, i'm assuming you've checked your fuse box?

second, check that the defogger element is actually conducting by putting a voltage meter (set it to measure ohms and it'll tell you if the circuit is complete) one terminal on the connector each side of the window.

third, remove the switch - it'll pop out with a little coaxing - unplug the switch from the cable and poke the tester into the cable. measure the two pins on the left against each other and the two pins on the right against each other - the two on the left drive the little lamp and the two on the right are the current for the window. as long as you have signal there, its not the cable.

fourth, test the corresponding pins on the switch - looking at the switch with the pins facing you ( and the switch up the right way) - the pins on the right are the lamp ones - there should be a circuit there but it will be quite high impedance so the needle will only move a little.
the other two are the defogger input and output - they should not conduct with the switch out but they should when you press the button. if they don't then you are the victim of weak-ass copper connectors.

thats the diagnosis......once you find where the fault is, you can probably repair it yourself if you're keen enough - i don't know how much work it would be to re-run the wires.

if its the switch, you can buy a new one or it can be repaired just by pulling it apart (make sure you do it carefully so you know how to put it back together) and bending the copper bits straight again (just keep the tester nearby so you can check when you have it right). it took me a while to get it right but i had no idea what i was doing - its kinda fun in a twisted sort of way :)

hope i didn't forget anything....good luck.

I should've said it before but I forgot. I looked at the switch and I noticed that the plug that connects to the switch seems like it melted and the wires touched. I'm not fully sure because it happened quite a while back and that's when I looked at the switch but tell you what. I'm gonna go to my car right now and look at it again so I can better describe what happened. Be back in a few...

OK I went and looked carefully I noticed this: One of the prongs that the plug would connect to on the switch (the prong I'm talking about is one from the switch) stayed connected and came out. If you look at the switch from behind and upright it would be the bottom left one. The way it came out looks like if somehow the two cable made a short circuit and generated so much heat that it melted BOTH plugs (the switch and the plug with wires) I'm sure that the switch will have to be replaced but I was wondering if I could get a plug and splice to make a new conection (new plugs) But I understand that I should check if that's the only thing that's F%*^ up. I took a picture but since I don't have a digital camera I don't know how long it will take me to post the pic.
:yell:

oooh, its hard to imagine what must have gone on behind that switch. :eek:

i see no reason why you couldn't splice in a new switch as long as you take note of which wires are for what. i think i explained that earlier but just to make sure....
with the switch gone, you are looking at just the connector plug coming out of the dash right? when its facing the right way, the two wires on the right are the ones you need to close with a switch to make the defogger go - the two on the left power the old switch's lamp. i don't remember what color the wires are or anything so you might like to make a note of them before you cut or pull the plug off.

the other option i mentioned is to buy a new switch. they are about $30 dollars here and i'd expect them to be a similar price in $US. let me know how you go!
:)

I finally exposed the picture of the defroster switch. The picture is with the dash panel removed and it has the blue arrow pointing at the plug that somehow melted and made a short circuit and a green arrow to where you can see the missing prong from the switch. I COULD splice on a new plug but I like doing good work and dunno if I would have to buy the whole electrical harness or WHAT?
On another note, I will be posting a different thread, but if anyone that reads this one can answer it I would appreciate it. The clock that is in the picture, is that the factory 2nd Gen digital clock? For some reason it does not fit/stay on. As you can see the feet are screwed up, etc. but it won't stay put for the life of it not even with glue.
http://pollito14.web1000.com/protege/defrosterclock.jpg

?!?!?!? what the heck are you doing to that poor car? :eek:

with regard to the switch, i'd get a new one (they are pretty shitty switches), trim back the wires as little as possible and put on a new plug (the white bit, you can buy them from most electronic stores).


as for the clock - hard for me to see properly but it doesn't appear to be the same as mine.....remember i am right-hand drive ;)

heres what my center bit looks like......

http://www.stefansandford.com/images/tach 004small.jpg

hope this helps