Hot orange wire on headlight switch connector

[Bubbasblazer]

I have a 84 k10, that I have had for 18yrs. When I bought it as a teenager it needed some love. The wiring I never got to really look at. I knew it was wonky in some places. A few months ago I noticed I had no dash lights. Popped and replaced the switch, thinking the switch caused the melted plug. The orange wire is still stinging hot. I did have a bad ground on a tail light socket I replaced and looking back I think,it may have lead to the hot orange wire. Now that the plug is melted I'm wondering if the compromised connection may be the cause now. One thing ever since I bought the truck still confuses me is that the dash lights dont dim its either all or nothing. Could this be related to the whole mess? I'm mechanically inclined, but when electric is involved I'm not a whole lot of good. Anyone have any suggestions? Thanks in advance

[bd]

Welcome to the site.

Which plug is melted?  Which orange wire is too hot to the touch - all the time or only when the running lamps are switched on?  Are any other wires hot?  Are you using incandescent or LED bulbs in the instrument cluster?  What does "all or nothing" mean - does the dimmer rheostat have any effect on cluster illumination?

[Bubbasblazer]

Thanks for the welcome. Its the infamous orange wire on the headlight switch. The wire is only hot when the lights are on. Everything is standard bulbs no led. The rhiastat has no affect on the dash lights, they will go out when turned all the way down however, there is no in between. Full bright or nothing.

[bd]

The orange wire is fused B+ and should be 12 volts at all times.  Use the 1983 Wiring Manual and "Diagnosing dash lights that don't work" to check the wire connections to the headlamp switch.  Someone may have altered the wire locations on the headlamp switch.  If the headlamp connector is melted, replace it and clean the wire terminals before reinserting the original wires into the new connector.  [The 1984 wiring manual is missing from our library, but there is no appreciable difference with 1983 models.]  There is no such thing as a rhiastat - it is rheostat.

[Bubbasblazer]

Thanks for the link dude, ill definitely be putting it to use.

[hatzie]

Here's the 1984 wiring manual...  http://www.mediafire.com/download/9ih3gy2t94wadpt/X8430_1984_GMC_CK_Light_Duty_Trucks_Wiring_Manual.pdf

[Bubbasblazer]

Finally had time,to look at this thing, between working 50+hrs a week and getting stock car ready for racing. The pair of orange wires have constant power, and get terribly hot when the switch is on. Followed the 1 orange wire,back behind the fuse box and followed the other to the CTSY light below the dash. The white wire from the switch heads that way as well. On the headlight switch both the Orange and white wires have power. I know the white should be a ground, but not sure why it has power too. Everything up to this point seems to be factory, I just have to follow them from there and hopefully come across something. If I don't see anything funky, I'm thinking ill pull each bulb and see how the temp. of the wire is affected maybe find a bad ground somewhere.  Thanks for download ill check,it out

[bd]

Recheck the orange lead running between the headlamp switch to the courtesy lamp.  If the orange wire is hot to the touch at the courtesy lamp check the socket and bulb.  Otherwise, follow the orange wire back toward the headlamp switch with your hand.  At the point it feels hot you will probably discover a short or a wire chafed to ground.

The white wire will check "hot" until the headlamp switch is rotated fully CCW to energize the dome lamp.  Fused B+ feeds the dome lamp directly - the headlamp switch is installed in the ground side of the dome lamp.