Mysterious wiring

[Matt Wood]

Hi Guys, i have stumbled across some really mysterious wiring under the dash, after removing the CB wiring that looked like it had been there from new i noticed a connector... this brown connector was in behind the driver side vent and seems to go up the a pillar? i could be wrong as its so tight to see in there... does anyone know what it is for??



While looking at this connector i noticed some electrical tape, i touched it and it simply fell off, this is what was underneath... this one seems to go into the big loom and then i have no idea where it goes from there, any ideas?

[Gary Lewis]

Matt - You don't have a signature so I don't know what year your truck is, but since the one wire color I can determine from your pic is red/yellow hash I know it is not an '86 as those trucks don't have hash or dots on their wires.  So I'll use the 1985 EVTM.

And searching it I find that a r/y hash wire is used on the carb circuits, like throttle kicker module, throttle position solenoid, etc as you can see in the schematic below.

But not all trucks got those systems, so that may just be a standard connector.  However, I can't tell which one that is w/o knowing what the other wire colors are.  Can you tell me?

As for the twisted-together wires, if they are brown they are for the exterior lights.

[Matt Wood]

thanks for the help here Gary, i think you are right, the connector is to do with the carb circuit and the bare wire i do believe is part of the interior lighting system.

[Gary Lewis]

Welcome.  Happy to help.