hatch_

the light does not come on when i press the rear defroster switch. the fuse under dash and hood are both good. all the defroster lines seems to be good as well. there aren't any broken lines. i took off the rear panels to check the plug. it looks like the driver side defroster plug is just a ground wire?? the wire runs from a screw/bolt straight to the plug. is the way it is supposed to be? how else should i be trouble shooting this? any advice is greatly appreciated.

mark@silbernage

Are you able to use a voltmeter and see if there is 12VDC back at the window/header grid? If the voltage is there, make sure the ground is good. If the voltage is not there, trace the wires back through the switch to the fuse and find out where it stops.

If you don't have a voltmeter, you can find them for less than $10 (though I'd get a nicer digital one at Radio Shack if you can) - anything that measures DC voltage and impedence (Ohms) is sufficient for most auto diagnostics.

Plenty of folks around here who can coach you on how to use the meter, and a few with wiring diagrams and color codes who can provide the clues.

Mark

fcm

Rear window defog is controlled, [timer] by the ICU, ICU problems are common on older Honda/Acura.

Questions...
Does the intermittent wiper function work?
Do all the warning chimes work, [key still in ign., lights still on, seat belt]?
Do the front side markers work, [blink on with signal or hazard lights, turn on with park lights, blink off with signal/hazard lights if park lights are on?
Does the dome light work off drivers door?

If any of the above are not working properly the ICU is your problem, even if all the above are good, it is probably still the ICU for the rear window defog.

You can also check the rear window defog relay. 94

hatch_

i borrowed a volt meter but i don't know how to use it. can someone help me with it? its a GB instruments GMT-312. my intermittent wiper and all the warning chimes still works. i've checked my relay also and it's still good.

fcm

Do you have power at the relay, should be two (2) pins with power when ign. switch is on.

Your Google search found these... http://www.google.ca/search?q=how+to...8&sourceid=ie7

You can use the meter to check for continuity between the relay, [output pin] and the power side terminal of the rear window defrost "grid". 94

hatch_

for checking volt for the grid, volt meter black pin goes to driver side plug and red goes to passenger side plug correct?

fcm

Red probe goes to power side, black probe goes to any ground point. 94

hatch_

i got no power going to the grid. how do i check the relay? its by the dash fuse box isnt it?

TheRealTegger

Did you check for voltage from the defroster connectors to a ground, skipping the grid entirely?

hatch_

i was about to check the relay, and realized it is missing. i just bought the car last week. is the rear defroster relay and engine heater motor relay(the one under the under hood fuse box) the same? i can't seem to find a rear def. relay for sale anywhere.

TheRealTegger

What make, model, and year is this vehicle? Relays are in different places depending on those things.

If and Integra... If a '90-'93, the defogger relay is at the top of the under-dash fuse-box, bottom left of the four in that location. If a '94-'97, it's the front one of the two at the front outside edge of the driver's footwell. If a '98-'01, its at the right side of the under-dash fuse box, in the middle, closest to the fuses.

If your relay is in fact missing, go get one from a wrecking yard. That is, frankly, a very odd thing for a previous owner to discard, and you really need to wonder why he did that.

geetee74

Man that response just answered a TON of questions about my 93 DA. My dome light does not come on when you open the driver's door, the right front marker light flashes but does not do the alternate flashing with the turn signal light like the left front, and my rear defrost is inop. So the ICU is the issue?

fcm

Most likely. 94

ckbawden

I'm having a problem with my rear defroster as well. It would not turn on at the switch in the dash so assuming it was the switch, I bought a new switch and found out after replacing it that the switch was not the problem. Now I see that the defroster turns on and off when it wants to. The dash switch lights up sometimes and when the rear window is frosted, I can see that it is working. However, I cannot turn it on when needed, nor will it turn off when not needed. My friend, a former Toyota auto mechanic, believes that it is the timer relay. He pulled that out for me and it is marked 12V No. RC-2203 Mitsuba Japan 12R. I can see lots of the RC-2203 relay parts available on ebay for about $10 used but I'm not sure that this is the correct part because nobody says its for the 1992 Acura Integra and since it did not work when I bought it (I'm the 2nd owner & the original owner is deceased), I'm not sure the correct one was in there. Does anyone know for sure the timer relay fuse and whether there is another more likely problem? I'm not savvy but my Toyota repairman friend is and I'm sure he can understand any reply you may give and help me out here. THANKS for your forum! Caroline