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I have been working on a 1970 Corvette L46 that I bought.
I found that the backup lamps are always on, even after I go to another shift than the backup.
I tested continuity on the switch and it stayed closed.
I ordered a new switch and installed it. Guess what. It did the same thing.
So I bench tested the old switch and I see it go from closed to open.
I tried to adjust the switch on the car but it never helped.
I'm thinking it may be the rod from the reverse link to the switch, is not long enough.
Anyone ever run across this.
I see pictures online that show the rod with a bend on both ends.
I looked at Paragon and it appears to be just like the one on my car and has only one bend.
Which one is correct?
Don’t know if you have a manual tranny? DO NOT Bend the connecting rod. The adjustment is made on the switch bracket. Once the switch is installed on the tranny, you connect a volt meter so that it lets you know when the switch is Closed (the car must be jacked up). Next place the 4 SPEED Tranny in 1st Gear, and loosen the metal bracket on the switch (you can see the elongated holes) so that the switch is OPEN. Tighten the bracket and then shift the tranny into reverse to make sure the switch is CLOSED. This a pain in the but, because you have to get into the car while it’s jacked up to change gears. A lift would make it simple, but my car didn’t.t have a switch, Thank you BUBBA.
Thanks for responding Eliredandblack. I appreciate you comments.
Here is some additional data.
It is an 4-speed. L46's came only with 4-speeds. I should of mentioned that.
I am working on it with my lift, which really helps.
I have been working with a DVM to test the continuity.
I mentioned that I did adjust the switch to see if I could make it go open. I could not get it to do that.
The switch that I took off was an original for the car and it bench tested as ok. As did the new one I installed.
I would of expected the switch would have made the open to happen with a margin to adjust it into. That is what is throwing me off. I expected the bar to be able to make the switch open, but it is not doing that.
I will attack it again in the morning. Thanks for you comments.
Here are a couple of pictures of the backup light properly installed on a couple of C2's. Unfortunately I couldn't find any similar shots of them properly installed on C3
Thanks for the pictures.
Notice that the rod has bends on both ends. That is what I was talking about.
My car had bends on one end only. Also the ones on the Paragon also only show one bend on the rod.
You may need to purchase a new rod, with the tiny clips. Are you removing the switch connector from the harness (that come from the firewall? When you adjust the bracket, that should most definitely cause the switch to OPEN.
I removed the connection so that I could isolate the switch for my testing.
My gut is telling me that the rod is correct for my car. I just don't understand why the rod does not have enough travel to open the switch.
Clearly, I'm missing something.
Here is a picture that someone sent me. Each end of the rod is bent 90 degrees and has the tiny clip on it. Is your tranny a standard Muncie? I will assume that switch opens when you bench test it? Are the bolts correct, so they allow the bracket to move?
That one also shows two bends.
The one on my car only has one bend.
This car was well taken care of before I bought it.
The person I bought it from told me that the backup lamps did not work correctly. When I looked at the problem, I found evidence that someone had been working on it because the wires came out of the connector. I fixed that by putting new Packard 56 connectors in it. After that the lamps came on but would not turn off. That is when I disconnected the switch and started to troubleshoot the problem. After that I isolated it to the switch not opening. I thought is was bad switch and installed the new one, but it did not fix the problem. After that, I bench tested both switches only find they do work when the the switch is moved far enough.
If your car has the original transmission, and shifter, then the only possibly would be 1. Bracket, 2. Rod. I can’t explain how or why those two parts work on your transmission, but that’s really the only thing left. On my car, there have been restoration parts installed that were incorrect and in at least one case, installed backwards. Take a picture of your tranny and the switch mech, maybe someone will see what’s wrong. The rod seems to be the thing that keeps popping up. Give Paragon a call, their tech support guys are very knowledgeable and may be able to tell you which rod is correct.
Yes I have. I live about an hour north of Atlanta. I seldom go into Atlanta. Were I'm at, there are more events to go to than I can keep up with.
We are having a show in Dahlonega on the 3rd. of July. I will be judging that one.
Today I will be at the cruise-in at the Varsity at Dawsonville Crossing.
Life is good.
Backup Lamp switch
