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Turn signal switch?

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Old Jul 23, 2017 | 09:43 PM
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BTFordGuy302's Avatar
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Turn signal switch?

Hey guys, I need someone to verify something for me. My truck is a 78 f150 2wd 6cyl standard transmission. My right rear brake light/tail light is acting up. If I hit the brakes it just goes out vs getting brighter and when I use my left turn signal it goes out as well without me hitting the brakes. The right turn signal works fine. I remember in another vehicle I owned the brake lights run through the turn signal switch. Is it the same on this truck? Is there a flasher fuse that could cause this? Thanks guys
 
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Old Jul 23, 2017 | 10:02 PM
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Originally Posted by BTFordGuy302
Hey guys, I need someone to verify something for me. My truck is a 78 f150 2wd 6cyl standard transmission. My right rear brake light/tail light is acting up. If I hit the brakes it just goes out vs getting brighter and when I use my left turn signal it goes out as well without me hitting the brakes. The right turn signal works fine. I remember in another vehicle I owned the brake lights run through the turn signal switch. Is it the same on this truck? Is there a flasher fuse that could cause this? Thanks guys
There is a flasher, but I would be more apt to believe you have a short or a bad turn signal switch.
 
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Old Jul 23, 2017 | 10:05 PM
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Ok that's what I thought, because there's two flashers arnt there? One for the front, one for the back? Didnt think it would be possible for it to quit halfway lol
 
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Old Jul 24, 2017 | 09:11 AM
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Originally Posted by BTFordGuy302
Ok that's what I thought, because there's two flashers arnt there? One for the front, one for the back? Didnt think it would be possible for it to quit halfway lol
It should just have one flasher
 
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Old Jul 24, 2017 | 10:36 AM
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Grounds. Remember, turn signal circuits run to both ends of the truck... check all the grounds at both ends, and check that the sockets themselves are connecting to ground - it is not unusual to find you have just cleaned off the sheet metal and ring connector, to discover the wire to ground strip connection inside the socket is crap. Make sure these are 100% before going into switches or flashers.
 
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Old Jul 24, 2017 | 11:03 AM
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As HoustonDave stated. I would start with the grounds before purchasing new switches. I just did this and it cured most of my lighting issues such as randomly going off. I'm still working on getting my backup light to work
 
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Old Jul 24, 2017 | 11:27 AM
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Originally Posted by Mb90nash
It should just have one flasher.
There are TWO flashers.

Both flashers look identical, are round with two prongs, but the 4 way flasher is a H/D type, has a louder CLICK.

T/S flasher plugs into the back of the instrument cluster at the upper left.

4 way flasher nestles into a bracket that attaches to the backside of the dash (near the cluster) w/a screw.
 
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Old Jul 25, 2017 | 06:08 AM
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Ok sounds good, I'll check out the grounds and see what they look like and I'll check out the sockets. As for the flashers I know my 85 had two so figured this would be the same. I'll dig in and see what's going on!
 
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Old Jul 27, 2017 | 02:16 PM
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Originally Posted by NumberDummy
There are TWO flashers.

Both flashers look identical, are round with two prongs, but the 4 way flasher is a H/D type, has a louder CLICK.

T/S flasher plugs into the back of the instrument cluster at the upper left.

4 way flasher nestles into a bracket that attaches to the backside of the dash (near the cluster) w/a screw.
I meant only one for the TS, I should have worded that better...haha
 
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Old Aug 1, 2017 | 02:02 PM
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Looks like the socket, the ground side in particular is pretty corroded. It did start working better once I popped it out of the assembly. It just dims insted of going out. I'm going to replace the socket when I get a chance and see what happens!
 
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