Hi folks

My reverse lights won't come on anymore. (i noticed my PDC wasn't working, and when i went to see why, determined my reverse lights weren't either, so they're clearly tied together - duh)

The fuse (F13, 5a) blows instantly on going into reverse. the lights do not even flicker. I have a dead short somewhere. I disconnected both tail light connectors and the fuse still blew, then i checked continuity on the tail light connector (wires side) and there was a dead short (duh)

I have a mini coop convertible. 5 speed stick tranny, aug 2004 build for sept 2004 delivery

I have the bentley manual, but it is very unhelpful with connection names and wiring diagrams, esp. for this part.
Can anyone help me by telling me the following:
1) likely reasons for a dead short, likely locations to look first
2) where the wires are routed for the reverse lights. It seems the wires go along the sides of the car for both? I am having a hard time finding them in testable locations.
3)Are there any connectors i can disconnect so i can start narrowing down the location of this short? Right now, all i know is that it is somewhere in between the tail light and the front of the car. not very helpful!

The bentley manual suggests that there is a switch on my transmission for when the car is in reverse. Power goes into this switch, and the switch goes straight to the brake lights (though it must split off somewhere to power the PDC). Is this true - that the computer never gets involved in the reverse light?

thanks!

I'm very good at troubleshooting, but if i don't have any test points, i'm lost.

 

Reverse switch is under the air box on top of trans IIRC...I'd start there and isolate the circuit. Power goes through the switch, so if the short is the switch(or after) then when unplugged, it won't blow the fuse anymore.

 

I was hoping to check that area last for two reasons:
1) i wasn't digging around in there when the problem started
2) it is a lot more work than checking everywhere else, if i know which other connectors it runs through, i can isolate and check them first, possibly making it unnecessary to dig around under the hood..

Does anyone know where the reverse light wires run, and more importantly, where the connectors for it are, so i can disconnect them and test each side separately?

thanks!

 

Your going to have more work tracing down individual wires than isolating the front half of the circuit from the back....There are 2 bolts holding the air box in and the connector is right up top that is spring loaded. Connector has 2 wires in it. Fuse 13 supplies power to the switch, switch closes and sends current to the backup lights in each taillight and also to the pdc. I don't know which side of the car that the wires run through, but I'd suspect the pass side since the pdc is there as well. If it were me though, I'd still try and isolate the circuit, by seperation and disconnecting components(taillights, pdc, switch)

 

To answer one of your questions...I'd start with the PDC, if I had to take a guess as to which component was causing a problem. Seen a few before that have had issues with shorted PDC sensors. It is located behind the Passenger side quarter panel trim.

 

I've already fully disconnected the PDC and both tail lights - the fuse still blows when going into reverse.

I was working on the driver's side sill area just before the problem - so i am guessing my short is there. I want to isolate that particular area first, so i'm looking for a connector before it, on the way to the tranny.

 

The wire color after the reverse switch is Blue with a yellow tracer, there is a multi wire splice on the drivers side along the rocker panel. THere is one connector under the hood(the round black one near the air box. No other connectors in the schematic, except for at the switch, taillights and PDC. Looks like you might be in for some wire tracing after all. What I've done in this case is to seperate the wires at the splice and measure resistance to ground on each one.