The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 02-19-2025, 11:34 PM   #1
Dodge68charger
Registered User
 
Join Date: Jul 2014
Location: Washington
Posts: 544
Trailer wiring harness help?

Id like to tow a teailer with my 69 C10 but never wired a truck wiring kit. I got some 7-way wire to splice under the dash. Do i just tap into the existing wires?
Turn/reverse/park/ etc.

Should i use a terminal strip and should anything be fused. Thanks
Attached Images
 
Dodge68charger is offline   Reply With Quote
Old Yesterday, 12:45 AM   #2
53burb
Senior Member
 
53burb's Avatar
 
Join Date: May 2004
Location: Queen Creek, AZ
Posts: 1,015
Re: Trailer wiring harness help?

typically you splice into the connections at the rear of the truck by the taillights....are you planning on using the standard 4-way plug? if so, brakes, left turn, right turn, and ground. Most people just use t-taps to splice into the connections....although, they are not the strongest.
53burb is offline   Reply With Quote
Old Yesterday, 12:54 AM   #3
Rick Bollinger
Registered User
 
Join Date: Mar 2018
Location: Colchester IL
Posts: 344
Re: Trailer wiring harness help?

If you are just pulling a flat trailer or most boats a flat four is all you need. If it is a camper with brakes and power then you do need a 7 pin. I have a 7 pin on mine and used this plug in for brake, tail and turn signal lights. with this there is no cutting just plug in at your tail light on back driver side of frame. https://www.bing.com/shop/productpag...29DD343ADD423E
If a brake controller is needed you need to run a 10 gauge wire to the back plug. Same way with a power wire to trailer for camper, 10 ga from battery, fused to the 7 pin connector. Hook up brake controller by directions with it.
Rick Bollinger is offline   Reply With Quote
Old Yesterday, 12:56 AM   #4
Dodge68charger
Registered User
 
Join Date: Jul 2014
Location: Washington
Posts: 544
Re: Trailer wiring harness help?

Going to run a 7 way plug

I need to run trailer brakes
Attached Images
 
Dodge68charger is offline   Reply With Quote
Old Yesterday, 01:12 AM   #5
Dodge68charger
Registered User
 
Join Date: Jul 2014
Location: Washington
Posts: 544
Re: Trailer wiring harness help?

Thank You
Dodge68charger is offline   Reply With Quote
Old Yesterday, 02:35 AM   #6
53burb
Senior Member
 
53burb's Avatar
 
Join Date: May 2004
Location: Queen Creek, AZ
Posts: 1,015
Re: Trailer wiring harness help?

i had the 4 way plug wrong....left/stop lights, right/stop lights, tail lights, and ground...I was looking for what Rick Bollinger posted...but didn't find it...,
53burb is offline   Reply With Quote
Old Yesterday, 03:46 AM   #7
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,700
Re: Trailer wiring harness help?

One of the wiring supplies makes an adapter that plugs in between the frame rail harness and the tail lamp harness with a flat 4 coming off of it. Plug and play. No cutting or splicing needed. https://www.amazon.com/55311-Vehicle...72995910&psc=1

Left--yellow
Right--dk Green
Brown--running/tail lamps
white--ground

Anything other than a flat 4 you can cut the pigtail to length and use those wires in your receptacle and bring wires from the front of the truck back like the trailer brake wire (12ga blue) and a 12v off of a circuit breaker (black)

Last edited by kwmech; Yesterday at 04:08 PM.
kwmech is offline   Reply With Quote
Old Yesterday, 11:18 AM   #8
Rick Bollinger
Registered User
 
Join Date: Mar 2018
Location: Colchester IL
Posts: 344
Re: Trailer wiring harness help?

53burb click on the link it takes you to one. If you want Google the part number and name to find other vendors with one. I ran wires from the adapter to my 7 way and added the brake and power wires from the front.
Rick Bollinger is offline   Reply With Quote
Old Yesterday, 11:32 AM   #9
72c20customcamper
Registered User
 
72c20customcamper's Avatar
 
Join Date: Jul 2018
Location: Catskill Mountains,NY
Posts: 8,859
Re: Trailer wiring harness help?

the only wire coming from front under the dash is the brake wire coming from the controller. And the only splice under the dash was for the brake light wire to the controller. Brake/turn and running lights are all spliced at the rear of the truck .

Newer cars and trucks everything is done under the dash but it’s just a plug and play situation as most vehicles that are rated to tow are pre wired .
__________________
Mark
72 c20 custom camper Husky edition,
66 SS396 Chevelle 1964 Hawk, 63 Avanti,62 lark
1969 AMX ,
1968 c20 stepside ,85 K20
1977 Suburban sold
68 anniversary.
72c20customcamper is offline   Reply With Quote
Old Yesterday, 11:34 AM   #10
PbFut
Senior Member
 
Join Date: Feb 2022
Location: Ca
Posts: 693
Re: Trailer wiring harness help?

The plug in adaptor at the rear is the way to go. The 4 wire ribbon already on the truck provides all the tail light function. If you need a brake signal or +12V for accessories then a separate run is needed. I would wire in a 7 pin, even if all you need is a 4 wire now. This gives you the ability to connect anything in the future. As for brake controllers, there are many. I found a Curt controller that uses a smartphone. It is a fantastic controller and very easy to adjust. Has memory for multiple trailers. Way easier to wire because to don't need to penetrate the cab.
PbFut is offline   Reply With Quote
Old Yesterday, 02:21 PM   #11
Rick Bollinger
Registered User
 
Join Date: Mar 2018
Location: Colchester IL
Posts: 344
Re: Trailer wiring harness help?

Pbfut I found one of thoes on clearance but have not tried it yet. I believe you would still have to run a power wire to the back to use it. The stock brake light wiring would not support the elect brake demand. I assume power comes from tha accessorie wire going to the 7 wire plug.
Rick Bollinger is offline   Reply With Quote
Old Yesterday, 02:53 PM   #12
PbFut
Senior Member
 
Join Date: Feb 2022
Location: Ca
Posts: 693
Re: Trailer wiring harness help?

Correct. You need a +12v. It's been a few years since I wired mine. Can't recall 100% but I beleive the unit will sleep so a full time hot will not drain battery. I run full time hot from a aux rv battery with factory relay for isolation and charging. I do not recall max 12v amps through the device for accessories. I used to haul race car many many miles.

Last edited by PbFut; Yesterday at 04:50 PM.
PbFut is offline   Reply With Quote
Old Yesterday, 11:19 PM   #13
slikside
Registered User
 
slikside's Avatar
 
Join Date: Jun 2010
Location: San Diego Co.
Posts: 1,192
Re: Trailer wiring harness help?

Subscribed.

Great info!
__________________
1972 Chevy C-10, SWB, Fleet, 350/350, PS, PB, HEI, mostly stock, Survivor.
slikside is offline   Reply With Quote
Old Today, 04:40 AM   #14
53burb
Senior Member
 
53burb's Avatar
 
Join Date: May 2004
Location: Queen Creek, AZ
Posts: 1,015
Re: Trailer wiring harness help?

Quote:
Originally Posted by Rick Bollinger View Post
53burb click on the link it takes you to one. If you want Google the part number and name to find other vendors with one. I ran wires from the adapter to my 7 way and added the brake and power wires from the front.
Thank You!!
53burb is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:48 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com