73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Electrical => Topic started by: 85chevyk10 on August 20, 2016, 08:54:33 pm

Title: Headlight switch wiring
Post by: 85chevyk10 on August 20, 2016, 08:54:33 pm
I am thing to wire my 85 K10 with an "EZ" wiring harness (which has turned into a PITA with the lack of diagrams and info sent with the harness) Here are the wires with their corresponding labels and colors I have left in the cab:

Headlight power - red
Dimmer power - light blue
Left tail park - brown
Left front park - brown
Left backup - light green
Backup power - light green

Does anyone know how to wire these to the headlight switch?

http://i1378.photobucket.com/albums/ah115/K10Chevy85/New%20Wiring%20Harness/image_zpsiqpqkemg.jpeg
Title: Re: Headlight switch wiring
Post by: hatzie on August 21, 2016, 09:47:23 am
The pinout is in the 1985 GM Light Truck wiring diagrams.
You can extract the old harness terminals from the 2977645 headlamp switch plug and install said plug on your new harness with new terminals.  The terminals are Delphi Packard 56 terminals.  If you threw out your old harness...  the Delphi Packard 2977645 connector may not be obsolete yet.  It was used on Ford and GM light switches.
Title: Re: Headlight switch wiring
Post by: LTZ C20 on August 21, 2016, 10:38:09 am
Hatzie, I messaged you about a week ago.
Title: Re: Headlight switch wiring
Post by: hatzie on August 21, 2016, 02:15:32 pm
Hatzie, I messaged you about a week ago.
Your box was full.  Couldn't send a reply.

Sent from my SM-P605V using Tapatalk

Title: Re: Headlight switch wiring
Post by: LTZ C20 on August 21, 2016, 02:31:53 pm
Hatzie, I messaged you about a week ago.
Your box was full.  Couldn't send a reply.

Sent from my SM-P605V using Tapatalk
My bad. Fixed.
Title: Re: Headlight switch wiring
Post by: 85chevyk10 on August 21, 2016, 07:36:51 pm
The pinout is in the 1985 GM Light Truck wiring diagrams.
You can extract the old harness terminals from the 2977645 headlamp switch plug and install said plug on your new harness with new terminals.  The terminals are Delphi Packard 56 terminals.  If you threw out your old harness...  the Delphi Packard 2977645 connector may not be obsolete yet.  It was used on Ford and GM light switches.

I have the old and new pigtails for the light switch. I also have the original wiring schematics. The problem is that I do not know which wires from the EZ wiring harness correspond to the gm light switch
Title: Re: Headlight switch wiring
Post by: hatzie on August 22, 2016, 03:06:41 am


I am thing to wire my 85 K10 with an "EZ" wiring harness (which has turned into a PITA with the lack of diagrams and info sent with the harness) Here are the wires with their corresponding labels and colors I have left in the cab:

Headlight power - red
Dimmer power - light blue
Left tail park - brown
Left front park - brown
Left backup - light green
Backup power - light green

Does anyone know how to wire these to the headlight switch?

http://i1378.photobucket.com/albums/ah115/K10Chevy85/New%20Wiring%20Harness/image_zpsiqpqkemg.jpeg

GM circuit numbers in the plug are shown on page 1A of the 1985 GM wiring diagrams.

Feeds
Headlamp power is circuit 2
Instrument Dimmer power is ckt 44
Park lamps power is circuit 40
Chassis ground is ckt 150

Outputs
Ckt 9 park lamps power out
Ckt 10 headlamps power out to dimmer sw
Ckt 156 dome/courtesy ground out... wye into the door switch wires

The backup lamp switch can be found at the bottom of the column (auto & Saginaw 3 on the tree) or transmission switch (other manuals). Liberate the plug from the old harness.




Sent from my SM-P605V using Tapatalk