Passenger tail light out

[anthonyd]

My passenger side tail light is not working. I know it’s not bulb because I swapped it with the working drivers side bulb. Also my dash light does not work. Could it be a fuse? If so which fuse do I replace. I have new tail light gaskets and I cleaned the grounds it was working but then the car sat for a few years and now it don’t work

[zxr250cc]

Hi all,

The car sat...

Mice or clean the grounds again. Check the wiring for nibble marks. Not a joke, mice eat wire for fun. Good luck.

Cheers

[anthonyd]

Okay Maybe a mouse ate a wire. Also my speedometer is not working

[zxr250cc]

Hi all,

Is the car auto or five speed? I am guessing you have checked the speedometer cable? Is there any noise from the dash or cable when driving? It was working fine when parked for storage?

Cheers

[andyofcolumbusmerkur]

My passenger side tail light is not working. I know it’s not bulb because I swapped it with the working drivers side bulb. Also my dash light does not work. Could it be a fuse? If so which fuse do I replace. I have new tail light gaskets and I cleaned the grounds it was working but then the car sat for a few years and now it don’t work

The car sat for a few years? Like how long 5 years? I would replace all fluids. Try to remove most of the fuel with a fluid transfer pump. Then get some new fuel + dry gas run through it just driving around easy and not boosting. Replace fuel filter. Also completely go through wiring. Disconnect plug harnesses and look for any cruddy business. Remove bulbs and check for cruddy business. Look at wires for any chewing. Check grounds of course. Then full tune up. If you just fix one little issue at a time (like a focus on a taillight) you will just be chasing little issues all the time and not enjoying the car very much. These cars are 30+ years old after all.

[my8950]

Hi all,

Is the car auto or five speed? I am guessing you have checked the speedometer cable? Is there any noise from the dash or cable when driving? It was working fine when parked for storage?

Cheers

Curious what auto or manual has to do with brake lights and speedo?

[andyofcolumbusmerkur]

Maybe he has a spare T9 or Auto cable to sell.

[zxr250cc]

Hi all,

The little plastic speedometer gear in the auto fails sometimes. Might be getting hard to find by now. I fully agree about changing fluids and doing full under hood electrical check and clean all connections. Fluids are CHEAP, motors, transmissions, not so much... Rear end oil is less than two quarts of gear oil, auto trans filter change with 4-5 quarts of Valvoline MaxLife or Mobil 1 ATF, change the brake fluid, little electric stick type fluid pumps to pump fuel out of the gas tank are less than $20 (I bought one recently) and all the grounds are easily cleaned with a Scotch Brite pad and a little elbow grease. Time is all that is needed and the satisfaction of all working better when you finish is quite pleasant.

The CRC QD cleaner is excellent stuff. One of the best for that and safe for plastic.

Cheers

[Ed Lijewski]

Inspect, clean, tighten, adjust lamp module harness connections.

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YMMV

[milehighXR]

I have to look at my taillights again too. I've done all the cleaning, crimping connectors tighter, cleaning grounds, new ground wire straight from the deal with all the bulbs to the chassis, etcc... everything short of running all new wires from the front to the back.

My left turn signal flashes faster than normal, then back to normal, then faster again. Right tailight always shows out, until I fumble f--- around with it, and then it works, until I drive the car over a bump.

It's the most important thing on my list right now, but I would like to fix it.

[zxr250cc]

Hi all,

Is it possible that the filament in the bulb is broken and connecting and parting with bumps in the road making it move? I have had that happen with a motorcycle in the past. Just a thought.

Do you have the electrical troubleshooting book for an 86? (All years probably the same for this.) There is a good diagram of the ground and power layout for the rear body on pages 11, 37 and 39.

I wonder if you were at lower altitude if the bulb would work fine? Just kidding of course.

Cheers

[milehighXR]

I've tried other bulbs.

I'll have to see if I can find the "high altitude principle use" bulbs next.

I have tomorrow off, so I should be able to get a few small projects done this weekend. As long as "she who must be obeyed" doesn't give me a big honey do list.

[Ford Guy]

I have had driver's side rear taillight issues for some time (the car has over 300,000 miles on it...) and have tried cleaning connections, new bulbs, new taillight units with their integral circuitry and none of that has solved this. I think there may be multiple faults in my case, as the Information Center in the dash has long shown that it thinks the driver's side rear turn and brake lamps are burned out when they are not. In my case, all the individual lights work fine, but using turn signals and brakes, brakes and running lights, running lights and turn signals result in different things. The fact is that not only is there an open circuit somewhere, but there has to be a short or something back feeding power through the ground circuit.... Most likely corrosion under one of the fuse boxes, or information center, or a connector to the back of the car.

[andyofcolumbusmerkur]

I have had driver's side rear taillight issues for some time (the car has over 300,000 miles on it...) and have tried cleaning connections, new bulbs, new taillight units with their integral circuitry and none of that has solved this. I think there may be multiple faults in my case, as the Information Center in the dash has long shown that it thinks the driver's side rear turn and brake lamps are burned out when they are not. In my case, all the individual lights work fine, but using turn signals and brakes, brakes and running lights, running lights and turn signals result in different things. The fact is that not only is there an open circuit somewhere, but there has to be a short or something back feeding power through the ground circuit.... Most likely corrosion under one of the fuse boxes, or information center, or a connector to the back of the car.

Wow 300,000 miles that's pretty good. Old Jeeps, trailers and Merkurs seem to take up more of my time than anything else in regards to taillights. It just seems like they get cruddy and act up. Adding a ground, and using new clean silver (not brass) based bulbs installed into new bulb holders helps. I'm thinking if I switched to led it would use less power and that could also help.

[milehighXR]

I'm thinking if I switched to led it would use less power and that could also help.

Are there any LEDs that fit, and provide proper brightness for daytime use? I saw some at Autozoo today when I was disposing of waste oil, and thought about trying some, but I need to fix other things first.