Backup Lights - 5spd Issues

Bullitt

Packin' Heat
Founding Member
Jan 13, 2000
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Houston, TX
So the 5spd swap was done on my car years ago, but the lights have never worked for very long and right now aren't working at all...

I'm fairly certain the switch is hooked up correctly as I get 12V at the lights (with both lights unhooked). Now, if one light or the other is hooked up, not only does it not light up, the voltage at the other light plug goes to zero.

As far as I can tell, he's run a wire from a positive source with the ignition switch on to one side of the switch, back out to splice into the harness going to the rear of the car. Connection is good at the switch and the harness going to the rear lights is in good shape, leaving the questionable part the connection under the dash. Right???

Any thoughts? I'm not sure why it would get 12 V with no lights hooked in and then lose it all when they're plugged in. Something can't handle the amperage or a loose connection under the dash???

BTW - lights do work when directly hooked up to the car battery.

Thanks!
 
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I figured someone would chime in.

Sorry I can't be of any real help. Maybe the lights or at one of them is wired up backwards, or the bulb is no good. Did you try new bulbs? Maybe there is a breaker under the dash for the reverse lights that gets overloaded. Did you try running a length of wire directly off of a battery and see if you can make each light come on?

I am putting a T5 in my 65 and am curious how to hook up the reverse light switch. It is the unit on the side of the transmission with 2 terminals right? What should each terminal be wired to?
 
The neutral safety switch/reverse light harness should have power coming into it on one wire, this wire should go to the switch on the trans. The other terminal on the switch should lead out back to the same harness and hook to the matching wire for reverse lights.

Once this is setup properly, the system should be gone through the same way as if you had a stock transmission in there as there is no longer any difference at this point.

As to why you are seeing voltage at the lamps but when bulbs are in you get no lights I'm not sure. Check to make sure you are geting 12 volts only when you have the trans in reverse. Is it possible you are shorting out somewhere along the way ? I would trace the wiring for the reverse lights back and make sure they are coming from the right spot.

Also, if you hook the ground of the lights up to ground and power them both direct off of the battery from the same source, what happens ?
 
Isn't the back up light switch the one on the side of the T5 with the 2 terminals on it? Whats the switch on the top front of the transmission with the wiring pigtail coming off of it? I thought this one was the neutral safety switch. I wasn't going to hook that one up, since the 65 never had that as a safety feature anyway.
 
Yes, the reverse light switch is on the side of the T5 and has 2 connectors on it. The neutral safety switch pigtail also has the reverse light wires in it. On a manual car, the neutral safety wires should just be bridged back into each other. The other 2 wires connect either to the trans or the shifter to make the reverse lights work.

EDIT:
I should say that the switch has 2 terminals on it not 2 connectors.
 
The neutral safety switch/reverse light harness should have power coming into it on one wire, this wire should go to the switch on the trans. The other terminal on the switch should lead out back to the same harness and hook to the matching wire for reverse lights.

Once this is setup properly, the system should be gone through the same way as if you had a stock transmission in there as there is no longer any difference at this point.

As to why you are seeing voltage at the lamps but when bulbs are in you get no lights I'm not sure. Check to make sure you are geting 12 volts only when you have the trans in reverse. Is it possible you are shorting out somewhere along the way ? I would trace the wiring for the reverse lights back and make sure they are coming from the right spot.

Also, if you hook the ground of the lights up to ground and power them both direct off of the battery from the same source, what happens ?

The splice into the factory harness is buried in the dash which I'll dive into this weekend. This is probably where the problem is...

Applied power direct to the battery and used the harness ground and the lights come on, so that ground is good. Has to be a voltage issue...