78 Turn Signal Help

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perky

Member
Joined
Mar 17, 2023
Posts
33
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129
Location
Eastern Washington
First Name
Perky
Truck Year
1978
Truck Model
C20
Engine Size
V8
Was out for a morning run, came back to the truck, started out, and signaled left, nothing. No hazards, right, or left signal. Got home and swapped fuse. Good momentarily, pulled into garage and then my mind got the better of means I had to retest. Lethargic clicking on one side, fast like a bulb was out on the other, then slowed and popped fuse. New one, taped bare ends of the bad rednecked trailer wiring at the socket (was disconnected for months) in an attempt to keep the 4 wires from grounding on each other, and tried again. Slow clicking to an eventual solid green, then another fuse out. Any suggestions? Sold the BM-trouble-you so we're down the 3 cars with 4 drivers, so turn signals would be nice.
 

dsteelejr

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May 25, 2020
Posts
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216
Location
Hudson, WY
First Name
David
Truck Year
1973, 1980
Truck Model
Cheyenne super C20 camper special, Sierra K25
Engine Size
350, 454
I’m not a pro at diagnosing turn signal issues, but I would start by checking the wires under the truck going to the tail section. If there’s a bad connection or a short it’s most likely at a splice or some sort of connection, or if wire insulation scrubbed off from chaffing. I’ve seen some shoddy wiring jobs under neither squares like people using quick splices, which should be illegal, for camper shells or trailer lights and they corrode because they are not sealed connnections. Even a proper splice with a heat shrink butt connector can go bad.
 

Jgonick

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Jan 12, 2017
Posts
232
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308
Location
West Texas
First Name
Joel
Truck Year
1985
Truck Model
K10
Engine Size
350
Background information if you could provide it. Bulb type- incandescent or LEDs? Had you done anything on the truck recently? (such as changing bulb or working on anything else etc..)
 
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