Have you ever been awakened by someone “laying” on the horn? Have you ever realized that that you were that idiot? Nothing has turned frustration to embarrassment so quickly—and I wasn’t even in the car.
Apparently, there was some short in the horn electronics, which was causing the horn to sound indefinitely. In the interest in mitigating the noise pollution & trying to return to what I could of my remaining sleep time, I just unplugged the damn thing—I’ll deal with it in the morning, or so I thought.
It’s been about a year since this incident, and today I decided to resolve it. In the intervening time, I have gathered from my participation in the DieselEscortOwners yahoo group, that this is a rather commonplace issue cropping up in cars of this make and vintage.
Issue
Apparently open–cell foam doesn’t tend to hold up well to 24 years of oxidization—go figure. This decay, causes the contacts that actuate the horn to make less than planned contact. I’ve noticed other issues associated with this, such as the Speed Control switching system failing to work at random times.
How it Works
When I press on the horn pad, the mailable cover presses against the electrically-connected copper spring plate. This plate compresses the foam beneath it, until some point of the plate comes into contact with the high points on the copper base plate, which is also electrically-connected. When contact is made, the circuit is closed, which actuates the horn relay, establishing current in the circuitry to the horn.
Repair
I went to the local rubber hose supply store and picked up some ¼”–thick by ¼”–wide sticky-backed open-celled foam stripping. I got 4′ for $1 and ended up using less than half of it.
1. Unscrew the two horn pad screws with a #2 (+) screwdriver. I used a flexible bit extension for easier access.
2. Disconnect the two wires that energize the two plates on the back of the pad. The terminals were two different sizes.
3. (if you have Speed/Cruise Control) Remove the four screws that retain the speed control switches.
4. Gently peel back the plastic cover to separate the two copper plates. This will require breaking the seal, where it is glued to the base-plate.
5. pop out the three white plastic fasteners that hold the two copper plates together.
6. Peel/rub off the old foam from both plates, being careful not to bend the spring-plate. Use rubbing alcohol to remove excess glue residue.
7. Cut your foam stripping into pieces, appropriate for filling in the low spots.
8. Reassemble and test.
Hopefully this can save you some embarrassment with your roommates!
Tags: auto repair, ernie