Back up Lights won't work along with hazard lights

[sgreiner1011]

Hi All, I posted this at Viper Alley too. Im new to this forum and just bought a 1994 Viper RT10. I tried to get it inspected and the back up lights won't work. This is weird, but I am getting 12V when I put it into reverse on both sockets. BUT, when I put one light bulb in, I measure the other socket and I get 0V. I tested the light bulbs, they are fine. I dont understand whats going on here. It couldnt be the backup switch since I do get the required 12V at the sockets, could it? As I was troubleshooting the back up lights, the hazard lights worked for a while, but now they wont come on at all. All the leads for the hazard lights are tied to ground now. There is something really messed up between the hazard lights and back up lights.

Does anybody have a schematic of the electrical system for 1994 Viper RT10's?

Please help as I have only 1 more day to get it inspected. This really is ******* me off.

 

[Motivated]

I too have no reverse lights or parking lights on my 97 gts, wonder if they share the same circuit. would like to see a schematic if one is out there. I have checked the fuses and bulbs too many times to count and they are good

 

[viper067]

I had the same problem, also on a '94 .... Viper Tech replaced the backup switch and it has worked fine since

 

[crazyspeed]

+1 on the back-up switch. It is possible that the switch on the trans is the trigger for the ground circuit ( anyone know?) ....so even if you have power at the bulbs.....?.....hence....

 

[Bill Pemberton Woodhouse]

Not uncommon. Call Mark Jorgensen at Woodhouse as we just fixed one of these last week.

402-677-2935
800-889-1893
[email protected]

 

[Roffle Waffle]

same problem with backup lights here

 

[sgreiner1011]

I ran a positive wire and used the same ground and the light worked. There is something really screwed up here. Still dont know whats wrong with the hazards.

I am getting a service manual that should be here tomorrow for a 94 RT-10. I'll post some scans of schematics of what you guys want after I fix my car.

Thanks for the help.

 

[Viper Wizard]

Simple system....on or off. Basic check: Key on, not running, bend a paper clip in a "U" shape, unplug the back-up light switch, take the paper clip and stick it in the two female terminals on the back-up light switch connector....go look to see if the they are on or off? Post your answer!

Tech Line: 914-763-3136

 

[sgreiner1011]

I will be checking that switch when I get the chance. Just havent gotten the chance yet. I doubt its the switch, but maybe it is. That wouldnt explain why the hazard lights arent working, would it?

 

[CWhiteRun]

Get a multimeter and test your fuses to make sure that you are seeing a 12V signal on both legs of the fuse. Don't use a test light as it'll light up on a weak signal that'll make you think the fuse is good, but in actuality it's not allowing enough voltage to pass through it. I'll get a scan of that circuit from my 2002 FSM....can't be TOO different from a first gen.

 

[sgreiner1011]

Thanks for the input. Yeah I tested everything. 12V at the fuse, the socket, tested the lights, etc, all are fine. I finally got the time to jack it up and get underneath to test the tranny reverse switch. Its bad, at least it looks like it. I shorted the leads and the reverse lights came on. However, I may have to bend the leads so its a better fit. Maybe one of the wire leads isnt touching the switch leads (loose). But anyway I am making progress. It still doesnt make sense that I am getting 12V at the socket when the the shifter is in reverse if the switch is bad. Unless the switch developed a high resistance while going bad and its so high that the light bulb doesnt get hardly any current so it won't light up. Just a theory for right now.

Now I have to troubleshoot my hazard lights, they stopped working when I was trying to troubleshoot the reverse lights.

If I would have to take the switch off, would there be tranny fluid that comes out? I have worked on cars that it does and doesnt.

 

[Madduc]

No fluid will come out if you change the reverse switch. But to test the way The Wizard suggested you only need to disconnect it.

 

[CWhiteRun]

Don't think so on the fluid, but I know it does need to be tightened to 20 ft./lbs.

 

[sgreiner1011]

Well, I got the switch out and tested it, it is open. So its bad. I also did the paper clip thing. So I went to consumer auto parts and ordered one. Jeez, it'll take 3 to 4 days. I guess this is what I should expect, having a rarer car. I will post my final results when I get the back up light switch in. The hazard lights I have on another post, fixed those too.

 

[Steve-Indy]

Feel for Ya , Man....I would politely suggest keeping a fire extinguisher on board...no joke!!

 

[sgreiner1011]

YES! Fire extinguisher, GOOD IDEA!!!!

 

[sgreiner1011]

Well, I got the new switch in and it works very well. I am going to get it inspected tomorrow. So it turns out that it was the back up light switch on the tranny that was grounding out onto the transmission every time it was supposed to turn the lights on. This is why I was receiving 12V at the light sockets at the back (It was "technically" still connected to the battery) When I put it into reverse, the lights would not come on because there was less resistance through the transmission/frame to the battery, than resistance of the light bulbs to the battery. So current, taking the path of least resistance, wont go through the bulbs to light them up. In the next couple of days, I'll get some schematics together to put on here to "give back" what I got from this forum. Thats what we are supposed to do on these forums, right? LOL, talk to ya later

 

[RTTTTed]

2000 ACR. Got my back-up switch today. Going to fix it tomorrow. chuck was correct with his paperclip test - that's what I did to mine week before last - Lights on!

As far as 'rare', a 6 speed manual trans isn't rare. Probably same switch used on vettes, Mustangs, Camaros Challengers etc. It's our system that makes the parts a waiting game. In the old days a backup light switch would be the same one used on automatics and standards. The parts would probably be used for ten years of more. But ... now everything needs to be changed evey couple years, different models are coming with different parts. Specialization or Government regs cause there to be sooooooo many parts and part numbers that no warehouse can hold all the different parts anymore. Many parts are stored in large warehouses in different parts of the country. Parts are also very expensive so it's too much investment to stockpile all parts until someone needs them so many items are warehosed by the manurfacturer.

Ted

Ted

 

[Roffle Waffle]

Ted Ted, where can I find this reverse switch in the car?

 

[RTTTTed]

The backup light switch is screwed into the passenger side of the transmision. Remove the cover plate under the car and the transmission switch is about the middle of the trans. 7/8" box end is what I used to unscrew and tighten the new one.

Ted

 

[Roffle Waffle]

thanks I'll look for it