rear wiper delay vs. courtesy delay?

[heiff]

I left my courtesy lights on the other day and ran the battery completely flat. After charging, I reconnected the battery, and [while reaassembling part of the dash] smelled burning...electrical burning. No smoke, smell subsides. The result:

• rear wiper no longer works (washer pump works, wiper motor doesn't)
• courtesy light relay no longer turns off the interior lights when I start the car - instead it turns them ON! courtesy lights otherwise perform normally (including delay function)

No blown fuses. I went through the rear wiper tests in the electrical troubleshooting manual, stopping just short of the last one which narrows it down to the motor, a wire running to the motor, or the wiper delay unit under the dash (which is what I suspect based on the burning smell).

There isn't any test for the courtesy light delay in the manual, but I notice on the wiring diagrams that a PB wire runs from between the courtesy delay and the rear wiper delay. I unfortunately can't tell what the wire "does".

Based on the smell and the lack of blown fuses, I'm fairly certain I've fried at least one of the delay relays - I just wish I knew whether the odd behavior of the courtesy light delay is because it's fried, or if it's behaving that way because the rear wiper delay is fried.

[RageRover]

Well, on mine, the rear wiper is slow while cold outside, not to mention it will not work sometimes, when I completely push the rear wiper button in. When I push the rear washer button, sometimes it used to not work.

Now mine worked fine flawlessly. I like electrical work, well to a point, but I recommend getting a wiring diagram of the rear wiper and washer circuit along with the courtesy lamp circuit. Trace from the wiper motor to a power source, whether it'd be a relay, computer, whatever, and test for continuity in that circuit (with the button on of course).

Do the same for the courtest lamp cicuit, which might be a bad ground, relay, maybe a burnt out tail lamp could be the problem. I remember back when I had to figure out why my aunt's Jeep Grand Cherokee's parking lights would come on when she depressed the brakes. It was a burnt out tail light bulb. But there are many other possibilities.

Good luck figuring this one out!

[heiff]

Ok, I think I might have this figured out. Here's my theory:

Part 1 - "Something" in the courtesy light relay has burnt up, which now fools the relay into thinking that the tailgate is open. This explains why the courtesy lights turn on and stay on (for 15 min) when the car is started. Starting the car is just resetting the "door left open" timer on the relay. How can I tell it's the relay, and not a switch gone bad? Because if one of the switches were actually stuck open, the alarm would go off 30 seconds after locking the car with the alarm remote (the alarm ecu comes "first" in the circuit).

Part 2 - Because the courtesy light relay thinks that the tailgate is open, it's inhibiting the rear wiper. Interestingly, the troubleshooting guide does not consider this as a possibility when testing the rear wiper system.

[heiff]

Yes indeedy, the courtesy lamp relay is the source of much badness! I find the RR down on the bump stops the other day, and begin to panic. Eventually I have a vague memory that the evil courtesy relay was pictured in the EAS circuit diagrams. And oh yes...it can inhibit the operation of the EAS as well. So much responsibility for one relay!

For a temporary fix, I stuck a plain ol' 4-pin relay in the socket, but removed the fuse from the circuit. This seems to appease the gods that control the rear wiper and EAS.

Just as an aside, where is everybody? There always seem to be one or two people viewing this part of the forum, but there are surprisingly few new posts...

[OkieRover]

You can find everyone over on the Hellllooooooo thread or the What Men Want thread.

[Dominic]

If anyboby need the relays or rear wiper motors im parting out 4 rrc's and have small shelf of 97 & 95 D1 parts www.checkercabb.com cheers Dom

[RageRover]

Heiff, your theory was right then! Cool man! I will make sure that if mine stops working again, to check out some of the stuff you posted here.

Good job.

[heiff]

Why thank you! Haha, I was about to explode when the EAS stopped working. Considering the impact of such a lowly component (the courtesy relay, I mean), you'd think it would get a bit more real estate in the workshop & electrical troubleshooting manuals.

[RageRover]

Oh I know, I yet need to find a manual, period.....damnit.

[heiff]

Wh...what?? You, a moderator, don't have a factory workshop manual?

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