RWD Relay

Does anyone know were the RWD relay is located on a '95 Bonneville SE? I looked under the glove box and according to the sticker it should be under the power window relay,and the radio relay but there is a blank spot there. Could the sticker be for another model?

Thank you for the help
JR Moen

At first, I thought you were looking for the Rear Wheel Drive relay. I was thinking... "I gotta get me one of those cars"... It's early, bear with me.

My 93 diagrams show that the ECC has the relay at position 3 in the relay center where you were looking but the manual climate control has a solid state relay built into the control head. This might be why your spot is empty. Can you verify which option you have: manual or electric climate control?

It's a manual.

Rear Window Defrost - RWD. It is shorting out and causing the car to stall. Are you saying the relay may be in the button?

No, not in the button but within the control head assembly:

http://img.photobucket.com/albums/v155/randman1/Parts/DSC01342.jpg

That little black box behind the middle knob is an all-in-one timer and relay for the rear defroster. This assembly is from a 93 parts car and the information above comes from my 93 service manual. I can't see yours being much different.

I'm taking a guess here. I'd bet that you'll find that your carpet padding is wet and corrosion is causing an excessive amount of current to be drawn. I've seen many-a-leak caused by either clogged sunroof drains and/or water entering the door seal channels and dumping onto the floor. I guy I bought my car from sold it cause he couldn't find the reason the fuel pump fuse would blow after about 2 minutes of running. I really never found out where the problem was but it dissappeared after removing the whole interior, scrubbing the floor pans and everything else under the carpet, and replacing the carpet and pads. This was more of an extreme case though and I hope yours isn't this bad.

This is what I wrote on Jan 31, 2005:
Hi Everyone,

I’m having a problem with my ’95 Bonneville and hope someone has an answer. The rear defrost button comes on by itself and kills the engine. When this happens I crawl under the dash and pull the fuse then the car would start back up. Well, lately this doesn’t seem to work. The other day I pulled the fuse and the light (on the r-def) wouldn’t go out for about 20 minutes, then the car started. The next day I was driving it and the RD light came on and the car died. The strange thing about this was I had the fuse pulled and the RD light still came on and once again I had to wait about 20 minutes till the car would start again.

What would cause the car to die when this comes on? Why would the RD light come on with the fuse pulled or come on by itself at all? I noticed the RD is connected to the hot/cold knob on the dash, could this be part of the problem?

Thanks for the help.
JR Moen

This is the responce I got:
THe fuse will not disconnect the RWD: it just disconnects the feed to the button. This button trigs a relay and the power feed to the relay is through a separate circuit breaker. ALso, the feed to this button is on same circuit as ignition.
The "RWD relay" is in fact a solid state timer and an electromechanical relay packed together. I think this unit (located in the "convenience center" probably under the glove box...not sure for this model) is the culprit, and possibbly has an internal short that sends erratic commands to the relay and that shorts the ignition circuit at same time. I'm just surprised the fuse does not blow out!

I'd pull the RWD relay off and see what's next.
THis circuit is "typical" of pontiac.
www.avigex.ca/xport/reardefogger.jpg

Does that answer sound right?
I pulled the control head assembly and noticed the black box and wires were really hot. Will heat affect the relay?

The description of the operation rather accurate and the diagram is pretty close too. In order to stop the current to the defroster, you'd have to pull the circuit breaker rather than the fuse. However, with the fuse pulled, the timer should not be able to be activated. If the defroster is just spontaneously activating without pushing the button or with the fuse pulled then I'd have to agree. Replace the timer-relay.

I'm not too sure about the button feed circuit causing the stalling though. The wires to the button and to the timer-relay are pretty small. If your stalling problem is caused by a high current drain, the wires couldn't handle that much. I'd expect the fuse to blow or the wires burn.

Thank you for all your help. This is a strange problem.

One thing I have noticed is when the RWD light comes on (with the 30amp fuse pulled out)I will pull the key out then put the key back in and turn it to the on position so the dash lights come on the RWD light will stay on for about 5 seconds then shut off. I will then try to start the engine and as soon as I trun the key the light comes back on and the car won't start.
I found if I open the door then put the key to the on position the RWD light will come on then start to dim then turn off. At that point I can start the car.
Every time the RWD light come on the car won't start or if it is running the car will die.

*EDIT* I just read your edit about the wires getting hot. Heat=current. The hotter it is, the more current that is going through there. You're getting closer...

If you take a look at that diagram again, you'll see that if there is a voltage or a ground differential to the PPL/WHI wire then the LED light can illuminate even if the timer-relay is not active. There is a ground buss connector (C340 looking at my diagram) under the carpet along the driver's sill. This is a 10 position connector that the grounds for the dome & vanity lights, defroster and oodles of other curcuits connect to. I'll bet you find something interesting there. This could be the reason that the defroster light comes on dim and when you open the doors.

If you do find some corrosion or even standing water, it would behvove you to inspect the rest of the car. There was another Bonneville owner that had the air bags blow while the car was idling as a result of corroded connectors at the airbag module. I can't remember if the airbag changed location to under the passenger's seat starting in 95 or 96

Thank you for your help. I'll check this out.