back up light question

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trudysduster

trudysduster

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I have been wrapping up the wiring on this 73 Dart Sport and I don't have back up lights. If I jump the switch on the tranny , they work. I put a 2 prong switch in after the 4 speed and replaced the 3 prong from the automatic. I put a new back up light switch in and it just don't seem to be making a connection when the shifter goes in reverse. Like I said, when the shifter is in reverse, if I jump the 2 wires on the switch, they work. Is there a different back up switch I need or what is going on. It is like when you put it in reverse, It doesn't push the plunger in enough to make contact. what am I missing here. I know someone has had this problem before.
 
trudysduster said:
I have been wrapping up the wiring on this 73 Dart Sport and I don't have back up lights. If I jump the switch on the tranny , they work. I put a 2 prong switch in after the 4 speed and replaced the 3 prong from the automatic. I put a new back up light switch in and it just don't seem to be making a connection when the shifter goes in reverse. Like I said, when the shifter is in reverse, if I jump the 2 wires on the switch, they work. Is there a different back up switch I need or what is going on. It is like when you put it in reverse, It doesn't push the plunger in enough to make contact. what am I missing here. I know someone has had this problem before.
Click to expand...

I am not sure about the use case, but in general with a switch, if jumping it works, you are essentially bypassing the switch. So either the switch part is bad (new parts can be DOA) or as you mentioned there may be an alignment issue. Can you manually depress the plunger to check if that activates the lights?
 
Do you have the switch on the clutch pedal asm?

Check the NSS w/an ohmmeter w/the wires disconnected. Shift into reverse and you should read 0 ohms. If not, faulty NSS.
 
I will check that. I may have an adjustment problem where the lever isn't going far enough to make good contact. I am going to check that also. The switch is in the back of the tranny, not on the clutch pedal.Thanks
 
Just pulled the new switch out and checked it. It is good. I hooked the 2 wires to it and pushed the plunger in and I had back up lights. I hooked the old switch to it and done the same thing and had back up lights. I noticed that the old switch had a slightly bigger ball plunger on it than the new switch. I put the old switch in the tranny and still no lights. I don't know what it is in the tranny that activates the switch for the back up lights but apparently it isn't doing the job.
 
EDIT............I was posting as you are. Sounds like something in the gearbox. Is there not an aluminum? gasket (only been about 20 years ago!!) on the switch? Maybe a thinner gasket?


Bill I'd pull the shifter rod off at the gearbox and manually put the reverse lever into gear and see if that works. This has just about got to be either a bad connection right in the switch connector, a bad switch, or something going on in the gearbox.

You should be able to put it into gear and measure continuity across the switch.
 
I had a similar problem with mine. There's a sort of cam shaped piece on the reverse lever internal to the trans that is what contacts the ball in the switch. On mine, if I kept pressure on the lever while in reverse it would just barely keep the lights on, but if you put it in reverse and take your hand off it would cut the lights. Unfortunately, there was no real adjustment on the trans interally, and tweaking the linkage didn't seem to help me much. Your mileage may vary with adjusting it. The only other idea I could think of would be putting some weld or epoxy on the cam inside the trans to build it up a little bit so it engages the ball further into the switch.
 
Here is a pic of that cam lever map63 mentioned. It may be worn. Disregard the red arrow.
 

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Put the switch back in and pulled the rod off and manually put the lever in reverse and still no light. I know the switch works because I manually activated the switch and had lights. I called the tranny show that worked on it and he told me that he didn't mess with the reverse lever when he put the kit in it but when I got it running to bring it up and he would put it on the lift and check it out. I am thinking something it worn in there just enough to not make contact. I was thinking about putting something on the plunger of the switch to build that up enough to see if that wouldn't do the trick. I don't see any red arrow in the pic but I am assuming that lever in the pic comes over and hits the switch that goes in the threaded hole there. I don't know what to put on that switch that would stay on it. Maybe JB Weld.
 
Can a tab be welded on that reverse lever? Just a thought. Or you can drill and tap it and insert a small plug. I know I may sound like an idiot but just throwing ideas out there. Lol.
 
Is there a gasket on the switch? How thick? Try leaving it off? I would NOT use any JB anywhere in that gearbox
 
Don't know what else to tell ya

Do without?

Separate toggle switch?

Separate switch on the linkage?

At this point if you really want this to work, seems to me tearing the gearbox down, and that is no guarantee

I guess you could drain the box, remove the side cover and see if the lever has full movement
 
You said the old switch was slightly longer,, try it, without a gskt.. if it works,, get an "o" ring for a gskt..

Perhaps probe the hole with the switch out,, and see if you can feel the "cam' move into place.. measure and modify switch..
 
I tried the old switch with the gasket off and it still didn't work. I am going to get under there and pull the switch and see if the lever is coming close to the hole or see what I can see. Right now I am more focused on this thing running. If I don't find something obvious, it is going back to the tranny shop. I hate when this happens. something is so close but so far away. he may have to do without. Thanks
 
Worst case you could make a bracket so that the linkage itself outside the trans hits the switch as mentioned. Wouldn't be the end of the world and probably not too much work, though annoying for sure. I fixed my problem by putting a whole new tranny in, but this time with 6 gears.
 
A couple of years back, another member had similar problems. If my memory serves, he figured out his was a early model trans which required a certain / hard to find switch. Same applies to neutral safety switches in automatics. There are different lengths, metal plungers, nylon plungers, 2 wire, 3 wire. It might be that neither switch you have isn't the correct one. If I didn't know exactly what parts are in the trans,
I would Google various year models.
If push came to shove, I might find a single wire neutral safety switch that would work there and let it signal a relay to turn the reverse lamps on.
 
Take the nss and have some of the material milled off for a deeper entry into the trans. Easier than drainin it and removing the cover. May only need to take .020" off.

Or, add material to the end of the plunger for more penetration.
 

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Give brewers a call. If anyone knows the correct answer to your four speed problem, and about different switches, it is them.
 
Why don't you just pull the switch out and measure for the depth you need?
 
d55dave said:
Give brewers a call. If anyone knows the correct answer to your four speed problem, and about different switches, it is them.
Click to expand...

I looked at Brewer's website. They show one switch, 64 and later
 
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