My daughter just bought an 87 jetta. The horn and back up lights don't work. I think they may both be on the same circuit. All the fuses are good. I think it may be a relay. If so, where is it located. It's German made and I can't find anything specific in a Haynes or Chilton manual.
Relay is in the relay panel under the dash near the fuses but it's the horn relay and not backup lamps.
The horn is neg.grounded/switched at the steering wheel. Remove the steering wheel and you'll see a metal ring on the back. make sure it's clean and shiny. Then, on the steering column you'll see a tiny metal tab. Make sure that's clean and shiny too and take a screwdriver and pry it out slightly. it should make contact w/the steering wheel ring. Also check the two wires in the steering wheel and make sure they are not broken.
If all that doesn't work, check the horns. Most VWs of that age have two horns...one behind the grille and one behind the fender (up under the car). They should get 12V power when the ignition is on. Pull the 12Vwire from each and measure for voltage.
If that doesn't work, check the ground wires at the horns for continuity to ground but you will have continuity only when the steering wheel button is pressed (hence the negative switching of the horns).
For the back up lamps, check bulbs and fuses. If neither is it, check the switch. Not sure where that is but on a manual transmission I think it's on the transmission itself and on an automatic I think it's under the shift lever.
"Matt B." wrote
Good information but before he does all that he should check the signal to the horns. I just replaced both horns on a Golf that the whole circuit was fine but the horns (both) just croaked with rust and corrosion. Earlier Golfs have both horns low near the wheelwell. Also, it could be a bad ground at the horns.
When I replaced the Golf horns I rewired it to have one of the horns out front of the radiator like the later Golf/Jettas (90 up?). The horn is louder like that and takes a couple of minutes of extending some wiring and soldering and shrink-tubing (soldered connections). Later vintage A2s have a different connector so if you pull replacements (if horns are bad) from an auto yard (used) snip the connectors off too, to be soldered with said shrink-tubing over joint, in the repair, if necessary.
The backup light is probably the age-old problem with A2s, being, the switch on the end of the transmission (if not the fuse) needs replacement. I think what happens with these switches is that they are not very well sealed and oil eventually seeps in the switch contacts. No matter how much contact cleaner is used they usually can't be fixed. (guessing it is a 5 speed automatic backup switches can last indefintely)
Harry
Thanks for that info guys, I'll give things a whirl.
well, I checked the fuse, the relay, all the wiring. Checked the ring under the steering wheel, and the connection with the tab. Nothing made sense. Current seemed to be travelling from one end to the other. Then, I pulled the fuse out again. It was so old and brittle that it broke apart in my hand. I've been playing off and on with this problem for the last month!! The horn works fine now, I replaced the fuse.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.