02 SC2 Intermittent reverse lights

[mistahsnowman]

Hi all--

I have a 2002 SC2 5-speed with ~72k miles on it. Over the past few months, the reverse lights have been coming on less and less frequently (while in reverse). I suspected the reverse switch might have been going bad (had a similar problem with my Ford Ranger a couple years back).

I found where the switch lives on top of the tranny, pulled it, and jumped the wires. When jumped, the reverse lights reliably come on and stay on. So this should pinpoint the switch as the problem.

I bought a new switch and put it in yesterday. No change. Reverse lights don't always come on. This makes me wonder if the shift linkage for reverse needs to be adjusted. Is this possible? The car shifts beautifully otherwise.

Any other ideas I'm missing? Any help would be greatly appreciated!

[Waiex191]

I've been down that same path. There is not really any adjustment in the shift linkage. My thought was wear in the shift tower on the transmission. I swapped to another junkyard part but still no luck.

[mattwithcats]

Pull the fuse in the fusebox, clean the prongs, reinsert.

Also, clean the grounds in the trunk..

Chasing the same thing myself...

[billr]

"My thought was wear in the shift tower on the transmission. I swapped to another junkyard part but still no luck.
..."

That make sense to me. Be brave and trim off the underside of the hex "head" on the switch, so it can seat a bit deeper in the tower. Ideally, an old sensor should be cut open so we can see how much can be trimmed, but just .010-.020" should make it operational again and probably there is at least that much extra material there. Just don't tighten the switch into the trans fiercely, not much more than finger-tight should be sufficient.

I f anybody wants to give this a try, but can't trim the switch, I'll do it free. Send PM (and then a switch).

[Waiex191]

Originally Posted by billr

Be brave and trim off the underside of the hex "head" on the switch, so it can seat a bit deeper in the tower.

I had the same thought. Chuck it up in the lathe and turn it down a bit. I do have access to a lathe, I'll give it a try one of these days.

[mattwithcats]

My switch is working fine, problem is in the fuse box...

Power goes to fuse box, through fuse, then to switch, then back to fusebox, then to reverse lights...

When power goes back to fuse box, it disappears...

I bet this is similar to the F5 issue, too much current is being drawn by the backup lights...

[Waiex191]

My fuses are good. Just like the OP, if I short the two wires together at the switch my lights come on.

[mistahsnowman]

Thanks for all the replies. I imagine you guys suggesting shift tower wear are correct. That makes the most sense to me. I'll have to see if I can pull some metal off the switch and see if that fixes the problem.

[billr]

How does that switch seal to the trans case, is there a flat gasket/washer on the underside of the hex? If so, I would take that gasket out and re-install the switch using just RTV sealant on the threads.

[mistahsnowman]

billr - that thought crossed my mind too, but there is no gasket, washer, nothing. The switch butts directly onto the transmission. I've attached a picture of the switch for reference.

[Waiex191]

My Saturn is parked and I'm trying to focus on other projects. Still it would be fun to chuck up my spare switch in the lathe and turn it down.

[billr]

Yeah, I figured that "remove the gasket" bit was too obvious a fix for somebody not to have already tried; but wanted to be sure. I was wrong about Waiex191 being on the "east coast" too...

Waiex191, any chance you can bump-up the priority on trying a trimmed switch? The OP and I are eager to find out if that works.

[Waiex191]

Originally Posted by billr

Waiex191, any chance you can bump-up the priority on trying a trimmed switch? The OP and I are eager to find out if that works.

I am really trying to finish the airplane and I've taken the insurance off my SC2, since I'm working from home. So probably not, but if I need to run to the EAA hangar to use the lathe I'll bring the switch.

I was from the East coast but escaped in 2005. I don't miss Connecticut but I do miss New Hampshire and Vermont. Used to ski a lot.

[billr]

OK, I understand. I think the OP will probably send a switch to me. For some reason, I was thinking you are in MA, close enough to the OP (in NH) that shipping charges could be avoided.

[Signmaster]

I went through this with my '95. The original lasted 23 years, the replacement lasted less than a year.

I didn't troubleshoot the original, and the replacement worked. When it failed I would get just a flash of light and then it would go out. Suspecting tranny seating issues like others here, I took the switch out to confirm. Regardless of how little or how much I pressed the ball down, just a flash. Jumping the wires showed full power to the lights.

Crap switches. Replaced it and the second new one is working for now.

YMMV, but rather than trim the switch just take it out to check it.

[mattwithcats]

Rock Auto

AC Delco D2209C

https://www.rockauto.com/en/catalog/...mp+switch,4240

[Waiex191]

I bought the Standard Motor Products switch and no joy. Signmaster's idea of crap switches has a lot of merit. I should have grabbed on at the junkyard.

[billr]

My guess is that the root problem is a bad design, not defective switches. It looks to me like the switches have little over-travel, so there is very little tolerance for wear of the switch plunger tip or whatever it contacts in the trans. If the trans part wears, even a "perfect" (zero deviation from print) switch may not work.

If I get one to trim, I will carefully measure the plunger travel needed for operation, over-travel available, and hysteresis to reset.

[Signmaster]

Originally Posted by billr

My guess is that the root problem is a bad design, not defective switches. It looks to me like the switches have little over-travel, so there is very little tolerance for wear of the switch plunger tip or whatever it contacts in the trans. If the trans part wears, even a "perfect" (zero deviation from print) switch may not work.

If I get one to trim, I will carefully measure the plunger travel needed for operation, over-travel available, and hysteresis to reset.

If I have it labeled correctly, the stocker might have been saved by trimming and seemed to be based on a wear issue. But with the housing being metal and it being a cheap part, I just replaced it.

I chucked the quick to fail switch, and the replacement that worked was a BWD part from Advance Auto.

[Waiex191]

I needed to use the lathe today, and was going to take the switch over. I had the original in the center console. Before I did anything, I checked the switch - I only got continuity once. That was with the ball jammed way down to the limit of its travel. So I chucked it in the trash and decided it was the switch. Likely my new one is NG also.