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Reverse light switch problems

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Old 11-21-2009, 08:05 PM
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WyattsRide
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Default Reverse light switch problems

I'm having problems with my reverse lights on my 1985 5-speed.

At first they didn't light at all in reverse. I jumped the wires at the switch by the transmission and they stayed on. I figured it was the switch.

I have a new switch installed and plugged in the wires. Now, the reverse lights stay on ALL the time. I made sure to use the existing pin (follower?). What possibly could be wrong now?

I do have the WSMs on Jim's CD. I'm trying to find this info there too.

Thanks for any help or suggestions
Old 11-21-2009, 08:33 PM
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Alan
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The switch isn't installed right... seems most likely.

Pull off one of the switch terminals - if the light goes out - then that must be it - essentially a mechanical issue.

Alan
Old 11-21-2009, 08:57 PM
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GregBBRD
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Dave Anderson just had this problem with a brand new switch also. The pin was activating the switch, which means that the actual "switching part" of the new switch sits too close to the pin. Is yours a factory switch or a reproduction?

Try turning the switch a half turn out from the transmission, until the lights go out. You can then either put another washer of that thickness under the switch...or grind that much off of the pin.
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Old 11-22-2009, 12:41 AM
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WyattsRide
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Originally Posted by GregBBRD
Dave Anderson just had this problem with a brand new switch also. The pin was activating the switch, which means that the actual "switching part" of the new switch sits too close to the pin. Is yours a factory switch or a reproduction?

Try turning the switch a half turn out from the transmission, until the lights go out. You can then either put another washer of that thickness under the switch...or grind that much off of the pin.
The switch I replaced I'm pretty sure was original. The new switch is from 928 Specialist so I'm not sure if it's a factory or repro.
When I took out the old switch it looked like there may have been a washer around the pin against the switch. I was just worried about the pin though. I put the pin in the new switch and installed it. I thought about that washer later but I couldn't find it on the old switch. I thought I might have imagined it or it was just a ring of transmission fluid on the switch. Could it have been a washer?
Old 11-22-2009, 10:05 AM
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the washer is probably called a sealing washer and it is made of aluminum or copper to seal the oil from leaking out of the trans, try following GB`s advice
Old 11-22-2009, 07:35 PM
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Originally Posted by GregBBRD
Dave Anderson just had this problem with a brand new switch also. The pin was activating the switch, which means that the actual "switching part" of the new switch sits too close to the pin. Is yours a factory switch or a reproduction?

Try turning the switch a half turn out from the transmission, until the lights go out. You can then either put another washer of that thickness under the switch...or grind that much off of the pin.

I followed this suggestion and it worked perfectly!!! I added another washer on the outside of the threads so it couldn't screw in all the way. Thanks sooo much gb!!
Old 11-24-2009, 03:47 PM
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6mil928
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Mine have been out since I bought my 81. It's on my short list of projects this winter.
Old 04-29-2019, 09:45 PM
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merchauser
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my reverse lights work properly, but when I put shifter in R, dash lights dim and I get a .5V decrease on my multimeter. (looks worse with dash volt gauge)
I plugged in my handy circuit tester into fuse # 40 (7.5 amp) and it shows a 3.4 amp draw. Osram web site for 7506 show bulbs are 21W and 1.9 amps.
without the fuse in the CE there is no dimming of lights and no power draw. fuse # 40 is also for mirrors, and RDK which I have bypassed.
?????
Old 04-30-2019, 03:01 PM
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Wisconsin Joe
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I'll guess you have a poor connection somewhere that is creating significant resistance. The current 'pushes through' and generates considerable heat when doing so.

If you are familiar with the way that a bad connection can melt a fuse without blowing it, this would be similar. But it could be anywhere along the circuit (bulb holder and grounds would be the first place I would check).
Old 05-06-2019, 01:36 PM
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merchauser
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SOLVED: I pulled apart the connection, for the reverse light switch, located in the spare tire well and gave it a good hit of deoxit.
no more voltage drop when putting shifter in reverse.



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