Turn signal what to test next? (1 Viewer)

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Sep 20, 2019
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ST.Louis MO
I need some electrical help. 1996 80 series land cruiser. The right rear turn signal does not light the bulb. 3 different bulbs, no change. Replaced the socket assembly....still no change. The kicker......it gets power. I have a analog volt tester. It gets 12-15 volts. The power pulses in time with the "fast blink". The left rear side gets closer to 15-20 volts. Front bulb works and flashes correctly. Any thoughts on where to look next?

update: I hooked up my trailer wires, and the voltage dropped. Could this be a relay going bad, or the flasher module?
 
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It's a lightbulb. If you're getting +12 then you're missing a ground.
And you're not getting 15-20 volts anywhere in a 12 volt system. Max would be 14.4 with the alternator charging the battery as read across the battery terminals.
 

ProjectsNMotion

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Are you sure the bulbs are good? Did you test them in known good sockets to verify that they're good? Are you having any sort of fitment issues where the bulbs aren't firmly touching the socket contacts?

Cheers
 

John McVicker

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If what you say is accurate, I believe there are only 2 possibilities:

A) bad bulb
B bad ground

EDIT:
Or as @Grandlooser suggest, a bad/no connection of the bulb to the socket.
 
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Joined
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ST.Louis MO
Are you sure the bulbs are good? Did you test them in known good sockets to verify that they're good? Are you having any sort of fitment issues where the bulbs aren't firmly touching the socket contacts?

Cheers

I have used 3 bulbs that work in other sockets (of the same type). Each one does not work in the "problem" socket. I am going to buy some new ones to try though.
 
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There is another possibility:
You could have a bad, high impedance connection upstream from the bulb that limits the current but will read 12V on an open circuit. You need to measure the voltage at the bulb when the bulb is in and properly grounded. Under this scenario, the voltage at the bulb will read close to zero with a high impedance connection upstream.
 
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Edisto Island
Nope. New bulb did not fix it.
I found my problem last night. The wiring harness from the passenger rear tail light follows a crossmember near the spare tire under the vehicle. There is a two wire quick disconnect that has a green wire with a yellow stripe the is your right blinker wire. If you pull that connection apart there is probably a lot of mud and corrosion in that connector. I had to end up cutting the connector off and just using wire nuts to join the wire back together. My blinker is working great now. Man what a relief to figure that out.
 

ppc

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Wire nuts should never be used in an automobile repair. The connection should be properly soldered or crimped and then protected by heat shrink tubing or similar.
 
Joined
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ST.Louis MO
I found my problem last night. The wiring harness from the passenger rear tail light follows a crossmember near the spare tire under the vehicle. There is a two wire quick disconnect that has a green wire with a yellow stripe the is your right blinker wire. If you pull that connection apart there is probably a lot of mud and corrosion in that connector. I had to end up cutting the connector off and just using wire nuts to join the wire back together. My blinker is working great now. Man what a relief to figure that out.


Thanks for sharing. I need to check that. I know a few of those connections are sketchy
 

lumbee1

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I had a turn signal issue recently. Left turn worked fine. Right turn would light normally however left brake would pulse softly. I had switched reverse and brakes to LED but turn signals were still incandescent. While troubleshooting, both left turn would softly light right brake and right turn would softly light left brake. It was really confusing. I checked ground on both sides and everything was good. Finally I just gave up, went to Walmart and bought LED 1156 bulbs for the brakes (I wanted incandescent to keep it simple) and installed them. All of my turn signal problems went away.
 
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I found my problem last night. The wiring harness from the passenger rear tail light follows a crossmember near the spare tire under the vehicle. There is a two wire quick disconnect that has a green wire with a yellow stripe the is your right blinker wire. If you pull that connection apart there is probably a lot of mud and corrosion in that connector. I had to end up cutting the connector off and just using wire nuts to join the wire back together. My blinker is working great now. Man what a relief to figure that out.

Any chance you could share a photo? I am under my truck now with the exact same problem. I am trying to go through some crappy wire work that another guy did on this truck.
Thanks!
 
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Edisto Island
Any chance you could share a photo? I am under my truck now with the exact same problem. I am trying to go through some crappy wire work that another guy did on this truck.
Thanks!
I didn’t take a photo of the splice. I have a photo of the complete repair of the harness. It right near the spare tire.

95C1F732-ABDA-49E6-BF82-939C513A2216.jpeg


41782EC6-4EE7-4E59-95A3-25186531ACD8.jpeg
 
Joined
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ST.Louis MO
I fixed mine. Under the truck, along the back bumper, closer to the passenger side, there was a female connector with a red wire and green wire connected. It also had a random green wire there. (This is the three wires on the right in the pic) This is for trailer brakes **I think**. Mine rotted and was falling apart. There was another connector, removed in the photo, that had green with yellow stripe wire and another green with black stripe. As I was trying to separate the connector the wires pulled out and it was obvious they were corroded. After splicing the wires together the turn signal works normally.

20201111_155202.jpg
 
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Interesting; had a similar problem with the right rear tail light bulb, the Cruise control would shut off, but only when my headlights were turned on (if a bulb was in that socket), no issue if the socket was empty. Replaced the bulb twice (assuming I had a defective new bulb) and the issue went away (maybe luck?).

Makes me wonder if this is a common issue with that harness connector??
 
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ST.Louis MO
Interesting; had a similar problem with the right rear tail light bulb, the Cruise control would shut off, but only when my headlights were turned on (if a bulb was in that socket), no issue if the socket was empty. Replaced the bulb twice (assuming I had a defective new bulb) and the issue went away (maybe luck?).

Makes me wonder if this is a common issue with that harness connector??
There is a different connector on the drivers side near the rear corner. I would imagine corrosion is an issue. It was not as much inside where the male/female connection is made, but where the wires go into the connector.
 

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