No Flashers, No Blinkers and Backup lights stuck on!

[Derrick]

75 vette with auto trans with all the problem above.

Initially the blinkers started acting up every once in a while, then totally quit....then the flashers started acting up (when on they would blink fast...then slow down....then speed up a whole bunch), then they quit working all together.

I checked the fuses under the dash and they are good and replaced the flasher and blinker relay (passenger side under the glove pocket, and in the rear passenger compartment).

Also does anyone know what the other relay looking contraption is next to the flasher in the rear passenger compartment?

 

[Bolisk]

With regards to the backup lights stuck on. I don't have an automatic trans. . .so I dont' know if it's similar or not, but with the manual trans, there is a rod that connects a shifter linkage to the backup light switch. This rod is held in place with two very small "c" type clips. . .that rust out and fall off after a while. It's possilbe that the rod disconnects when shifting from reverse to a forward gear and left the reverse lights toggeled to on. At the very least, you could probably crawl under the car and flip the switch to off, until you have time to fix it.

 

[Curtis]

i think your reverse light switch is on the bottom of the shifter itself, but all this sounds to me like you have some wires melting together and shorting out somewhere. Look closely for hot wires in the area of exhaust and starter and possibly under the dash in the pedal support area.

 

[Derrick]

Thanks for the input guys. I found the neutral safety/backup light switch at the base of the shifter. I can see there is a little pin on the shifter that moves a sliding piece in the switch. I've got a new one on order.

I found that the rectangular relay looking thing in the rear passenger compartment is actually part of the factory security system.....according to some researched posts on this forum.

I did a thorough inspection of the rear tail light wiring and found that "bubby" had made some wire splices without the use of plastic electrical connectors so I fixed those problems up. I plan to look at the engine bay wiring harness next.....still no blinkers or emergency flashers.ad

Again, thanks for the input. I replaced the turn signal switch in the steering column about a month ago. Do you guys think I could have shorted it out again or is it just some melted wires somewhere else or possibly a ground issue?

 

[lone73]

... I replaced the turn signal switch in the steering column about a month ago. Do you guys think I could have shorted it out again or is it just some melted wires somewhere else or possibly a ground issue?

Could be all of the above. I worked as a repair technician (electronics tech) in the semiconductor manufacturing industry for 18 years, fixing the automated machines that are used to make wafers. I was working with a group of techs here in Austin. Whenever something mysterious started happening with one of the machines the first thing everyone would ask is - what was done to it last and when? About 75 percent of the time that was where we needed to fix something.

As an aside, when I first took my dash panel out, the one behind the steering wheel, I found several wires that had melted together that lay atop the speedo and tach. You might want to check there too.

good luck with it

 

[Derrick]

I checked everywhere in the engine bay yesterday and I didn't find any problems. However, I found that if I unplugged the neutral safety switch then the blinkers worked fine. Then a couple minutes later the emergency flashers worked fine. I then plugged the neutral safety switch again and the blinkers and flashers stopped working. I tried 3 or 4 iterations of this with the same results.

Maybe the safety switch is the root cause and its tripping a circuit breaker....which would explain why it takes a minute or so for the emergency flashers to start working after it's unplugged (needs time to de-energize.)

Do you guys know if the neutral safety switch has anything to do with the "fasten seat belt" light? That's also stuck on when I turn the car on and put it in any gear.

 

[Derrick]

UPDATE:

Installed a new neutral safety switch today and the backup lights, blinkers and flashers all work fine now!

However...new problem came up after installing the switch. My tach, oil pressure gauge and temp gauge only work when the car is in reverse.

Does anyone have a good instrument cluster wiring diagram? I have a chilton's book but there's no diagram for the cluster.;help

 

[wishuwerehere82]

It sounds like a ground problem.
I would start at the backup light ground and work forward. Somewhere there's power being diverted from its intended path.
Follow the black wires from the lamp connectors to the frame grounds and clean them up.

 

[Derrick]

Thanks for the response. I checked and cleaned all the grounds. I found a nice wiring diagram on the net and found that someone, for whatever reason, had spliced one of the connectors on the interior harness incorrectly causing my short. All my gauges, blinkers and flashers now work!