Sunday, July 15, 2007

Backup Lights -- 1/2 way there

As part of doing the tail lights, I needed to fix the backup lights. They were not functioning. I took the console out, which exposed the B&M shifter. It does appear to be a B&M Megashifter, but my model looks a bit different. The installation completely hacked up the B&M base, presumably to force it into the console. The installation just is a plain boot, and the shifter indicator sits inside the console so that it isn't visible. It actually looks fairly clean, you just have to pay attention to what gear you have it in.

In the picture above you can see the shifter cable running up from below (red) and the now exposed shifter indicator (red peg above the black plastic indicator slide). There should be a reverse (backup) indicator switch and neutral safety switch which, when wired properly, will prevent the car from being started unless the car is in Park or Neutral, as starting car in another gear usually results in an unexpected, unpleasant experience. This shifter doesn't appear to ever be wired for lights and the "box" of spare parts did not have any switches included. A quick look on the web and I found both switches at Summit racing (really the same switch is used for either backup or neutral safety.) I ordered two last week so they would be here when I got back from my week vacation.

I took the picture above while testing the circuit with the switch inserted. But before I get ahead of myself, I had to trace the backup light wire in the wiring harness that runs along the driver's side of inside the body just along the trunk line and under the back seat, so once again the back seat gets pulled.

Ok, now, which one? Ah, a nice wiring diagram can come in handy. I have seen several for sale on ebay (colored schematics, plastic laminated) for about $12. They look pretty nice -- but I found the 68 Le Mans Service Manuals and Fischer Body Manuals online at Ron's Pontiac Page. These normally go for about $30 or so for a reprint, photocopy or CD. They don't appear to be copyrighted, so hey, more power to Ron! Anyway, a quick inspection shows that its the dreaded light-green wire that's the target. To test the backup lights, I cut the light green wire as it came out of the fuse box (make sure ignition key is off, it is hot!) and cut into the light green wire under the seat -- wired the switch in -- and what do you know, both reverse lights work when the switch is tripped.

That's pretty much all I got done for the day -- after running a wire under the carpet from the backseat to the shifter area, splicing it to the harness wire under the back seat and buttoned up the carpet -- I called it the day. Still need to mount the switch. I will mount both reverse and neutral safety switches. I'm still just trying to get it inspected, so I'll just wire up the neutral safety switches and run them under the carpet up to the dash and leave them for now.

One final comment is I have an intermittent short between the brakes and the dashboard flasher lights. It is currently not failing; so I'll have to wait until it happens again to diagnose that issue. Anyway -- 1/2 a step closer.