78pacer

I replaced the back-up switch on my '95 last fall. Yeah, it was a PITA, but well worth the effort....esp with a tinted rear glass. I got the switch thru Ecklers and used a big-assed 7/8" box wrench to crack it loose. Then it easily unscrewed by hand. It's not a difficult fix by any means and yes...very common on our cars.
Good luck.
Mike

Dave C

I have the same problem in my 86 (4+3) - is the switch in the same approximate location? I'll start by checking the fuse and the bulbs...

Thanks
Dave C
86L 4+3 Coupe (49k miles)

CDN/AZ LT4

Not sure about the '86's...I had the exhaust out anyway and I undid the slave cylinder to get better access to the back up light switch. Got a replacement from Mid America for $36.99 plus shipping. Good luck with yours. Peter

asjwalsh

I posted this in 'general discussion' but it quickly got lost so just added it to this thread..hope that's not against any forum rules

OK, so here's my story... First I have not added to a previous thread about BU lights because I did that a few weeks ago and got a snotty warning from a mod that it is against the rules to dredge an old (over 45 days) thread up. Quite why is beyond me, if it is brought up to bring new light to an old problem. If it is to advertise or rehash an issue then maybe I can see the reason, but I digress.

So I bought the 94 Admiral Blue coupe a month ago. I felt confident that I had checked as much as I could before parting with my cash, but nevertheless overlooked the back up lights. One side note is that in the glove box the previous owner had left a weird looking thing in a plastic bag. The dealer had no idea what it was, but I put it in my garage for safe-keeping, along with a million other useless gadgets that we all cannot throw away.

Well my daughter informed me the other day that the back-up lights were not working so I started researching the issue. Plenty of old threads here informed me if it wasn't the bulbs or fuse it was most likely the switch. More research revealed the identity of that odd item now somewhere in my garage. A new back up switch that the previous owner hadn't got around to replacing, worth anywhere from $80-$130!! Phew! I found it and started to work out how to get it in. According to other threads you can get it in without removing the exhaust pipes or the clutch actuator. So off comes the front spoiler, up the too steep ramps it goes, and under the car I dive.

Upon identifying old switch I discover it is finger loose! Weird...I guess previous owner had started to change it but ran out of time. So with the tips of two fingers I undo the switch 1 degree at a time until it finally falls out. Yes! This will be easier than I thought. Grab new switch, and that is when I realise it is impossible to hold it and twist it into the gearbox case. IMPOSSIBLE!!!! So I have to take the clutch actuator off. Grab a wrench and the top nut comes off too easily. That is when I notice that the bottom nut is rounded off.....Try as I might, I cannot free it. Did I mention I started this job at 0650, the wife is due home at 1100, and is expecting a lunch date. It's now 0830 and I have just worked out why the previous owner never put the switch in; he couldn't manage it. Bummer.

Not only that, but I just realised that I have a car I cannot drive anywhere without losing gearbox oil. Nightmare. If it had been about 1700 it would have been beer time. Instead, I sat dejectedly wondering what I could do. And that is when I came up with an ingenious solution. Taking a 3/4" wrench, some duct tape and a huge dose of patience I spent the next hour carefully balancing the switch in front of the hole by resting it on the wrench, then using my finger tips to just make the screw rotate a few degrees. I must have done it 100 times, easily, only for it to fall onto my face, but suddenly, 101st try, the threads engaged, I lowered the wrench and the switch was still attached. More finger tip twitching and good grief, I HAD IT!!! Grab the 7/8" wrench and tighten it up. The act of replacing the wiring was a doddle by comparison.

Finally, ignition on, walk to the back of the car with baited breath, and lo and behold, four white lights.

The car was back together, the garage looked as though nothing had happened, I am out of my yard work clothes freshly showered. The wife comes home, looking tired and says "do you mind if we skip lunch, I'm a little tired. By the way, have you done the laundry?"

Anyway, that's my story, just wanted to share it with y'all

Dave C

THAT'S A GREAT STORY - ONE WE CAN ALL RELATE TO - AND VERY WELL WRITTEN, BY THE WAY!

Thanks for sharing!

Dave C
86L 4+3 Coupe

RUU

Remind me never to check my back-up lights...

asjwalsh

Thanks guys. The lights actually come in quite handy at times!

Big Craig

The shop let my 91 6sp car pass inspection last time with these lights out, but I'm not sure they'll let it go by again ... besides, the back up lights should work. Is it going to be possible on ramps? Anyone have pics of the area I should be looking at?

cvette98pacecar

Installing a Avic Z140BH with a backup camera, Does the reverse light switch wiring go into the CCM or does the fuse power the switch than directly go to the reverse lights?

MatthewMiller

Raising this thread up from the grave because I too have a 1996 LT4 (ZF6 trans) with no backup lamps functioning - neither the actual backup lamps by the license plate nor the quarter panel lights. The bulbs seem fine (they have continuity through them and the filaments are intact), and the fuse tests out good. The bulb sockets don't appear to have power going to them with the key on and the shifter in reverse.

I recently did a clutch job and checked the switch on the trans while it was out of the car. When I moved the shifter into Reverse, the switch had good continuity through it. When I moved the shifter to Neutral or any forward gear, the switch had no continuity. Also, the fuse has 12V when the shifter is in Reverse and only a few mV when the shifter is in any other position. So doesn't that mean that the switch is functioning properly?

Anybody have any thoughts as to where to look next?

sailorsteve

For the bulbs to light, you need grounding as well as power supply. Since none of them work, look for a problem common to all of them. I would suspect a grounding issue, often arising at the ground attachment point, see G 401 on the diagram.

Use your continuity tester to see if the ground contacts in the bulb sockets are in fact grounded.

If this tests ok, use the tester between the fuse and the sockets to see if the circuit is intact. Prime suspects if it isn't would be the connectors, again see diagram.