Tow package - white wire

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JAvy

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Hi all,

'98 Silverado with factory tow package. Wiring up a 7/4 pin Hopkins receptacle. Very straight forward, uses a T to splice into the factory 4 pin taillight harness, and then separate wires for the +12v, brake controller, reverse lights and ground.

The harness coming back on the driver's side frame rail has:

Blue: terminates under hood, will connect to brake controller

Orange: terminates under hood, will go to 30A 12v aux post

Light green, dark green, brown and yellow: go to 4 pin taillight harness connector.

White wire: I assumed this was ground. I wired only the 4 pin side up for now and tested the lights. As soon as I hit the brake it blows the STOP/HAZ fuse and I lose everything. Is the white wire actually for the reverse lights? When I disconnected it from ground everything worked as it should, but I can't seem to get a positive voltage indication on it when the truck is in reverse. I followed it up to the engine bay but can't find where it terminates.


Thanks!!
 

454cid

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I think white is positive on our trucks. I haven't wired up a connector in probably over 10 years, Though. I do remember finding out that there isn't really a solid standard for the wire colors.
 

Nad_Yvalhosert

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Truck side reverse is a dark green. Not to be confused with light green, being right turn/brake. Black is ground. Never seen a white. Perhaps someone spliced in a different color?
 

grampadirt

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The white wire is ground,it goes to the frame rail behind the bumper.Peel back the black wrapping tape and follow it.Both of my Suburbans are like that,I would assume trucks are the same.That white wire should terminate at the frame.
 

JAvy

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The white wire is ground,it goes to the frame rail behind the bumper.Peel back the black wrapping tape and follow it.Both of my Suburbans are like that,I would assume trucks are the same.That white wire should terminate at the frame.

That's what I figured, but when I connect it to ground it blows the STOP/HAZ fuse when I hit the brake. Weird. I'll do some more testing and report back.
 

Chewy11B

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So your 7 and 4 should be grounded using the white wire.

Brown is tail
Dark green right turn/stop
Yellow left turn/stop
Orange 12v feed to 7 way
Blue brake signal feed
Light green is reverse
White is ground

Did you connect a brake controller??
 

JAvy

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So your 7 and 4 should be grounded using the white wire.

Brown is tail
Dark green right turn/stop
Yellow left turn/stop
Orange 12v feed to 7 way
Blue brake signal feed
Light green is reverse
White is ground

Did you connect a brake controller??

I haven't connected the brake controller yet, that's what I meant when I said I've only connected the 4 pin side of the plug so far, and it works fine.

I will get around to the remaining wires for the 7 pin side soon
 

Chewy11B

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Ok so in the flat 4 you hooked up, on the trailer wiring side, should be white, brown, green, and yellow?
 
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