Generation Specific => Second Generation 1970-1981 => Topic started by: Dwills on June 07, 2022, 07:12:45 PM

Title: Main Body Wiring Harness
Post by: Dwills on June 07, 2022, 07:12:45 PM
I have been working on a restoration for longer than I can remember and I am very close to finishing the floor pans and am looking at the next phase.  One of the things I am debating is replacing the main body wire harness under the dash.  This one intermediates me a bit since I do not want to trouble shoot it and think I should just replace it.  My issue is I want as close to original as I can get.  I know several companies make harnesses new (painless is one),  has anyone bought any of these and swapped them in.  Again think original, I understand updated to blade fuses and such but I would like to stay original if I can.  Car is a 77 SE.

Thanks for the info in advanced

Doug
Title: Re: Main Body Wiring Harness
Post by: quizkid32 on June 08, 2022, 04:52:06 AM
https://www.lectriclimited.com/

I have bought a few harnesses from them. They are exact to the originals, but expect a few weeks wait if the item is not in stock.
Title: Re: Main Body Wiring Harness
Post by: roadking77 on June 08, 2022, 06:40:17 AM
Unless its been super messed with I would consider leaving it. When I restored my 77 there was literally not a bolt that wasnt touched. Every wear item that could be replaced was. I figured no better time than when the car is a bare shell to put back everything new. I was going to go the new harness route but read a blip from a guy that wire itself generally just doesnt go bad. So I rolled the dice and left it alone. There was some add on stuff that was easy to trace and remove, speaker wires, replacement radio wires some old alarm stuff etc.

After the car was put back together everything worked fine electric wise with the original stuff installed back in place. Only problem I have had was the brake lights went out but that was the under dash switch.
Title: Re: Main Body Wiring Harness
Post by: rkellerjr on June 08, 2022, 01:37:13 PM
I believe M&H does factory replacements and I think they will attach factory plugs. You'll need to contact them. Last I talked with them, they were my go to instead of painless because they use factory plugs

http://www.wiringharness.com/
Title: Re: Main Body Wiring Harness
Post by: Dwills on June 09, 2022, 06:18:54 PM
Unless its been super messed with I would consider leaving it. When I restored my 77 there was literally not a bolt that wasnt touched. Every wear item that could be replaced was. I figured no better time than when the car is a bare shell to put back everything new. I was going to go the new harness route but read a blip from a guy that wire itself generally just doesnt go bad. So I rolled the dice and left it alone. There was some add on stuff that was easy to trace and remove, speaker wires, replacement radio wires some old alarm stuff etc.

After the car was put back together everything worked fine electric wise with the original stuff installed back in place. Only problem I have had was the brake lights went out but that was the under dash switch.

I appreciate your insight and I agree that wire does not go bad, I disagree in that wire insulation does go bad, and after a certain time the plastic on the connectors gets brittle and comes apart.  So while I desperatly want to not mess with it it would suck to put everything back in the interior and in another couple years have to replace the harness because insulation starts coming apart
Title: Re: Main Body Wiring Harness
Post by: Dwills on June 09, 2022, 06:20:10 PM
https://www.lectriclimited.com/

I have bought a few harnesses from them. They are exact to the originals, but expect a few weeks wait if the item is not in stock.

 I had not heard of them but will check into it, Thanks
Title: Re: Main Body Wiring Harness
Post by: Dwills on June 09, 2022, 06:21:08 PM
I believe M&H does factory replacements and I think they will attach factory plugs. You'll need to contact them. Last I talked with them, they were my go to instead of painless because they use factory plugs

http://www.wiringharness.com/

Several people on facebook have suggested them Thanks
Title: Re: Main Body Wiring Harness
Post by: Dwills on June 12, 2022, 10:17:03 AM
So those that have replaced an under dash harness, How difficult was it ?????
Title: Re: Main Body Wiring Harness
Post by: firebirdparts on June 13, 2022, 09:48:35 AM
The factory put the harness in the dash and then put the dash in the car.  To me it's easy, but I've looked at 100 of them and I like wiring anyway.  I don't ever ask "what's this plug" in a thread.
(http://www.firebirdtransamparts.com/techinfo/harness/dash1.jpg)
It's somewhat helpful to know what's an add-on, I guess, and not get confused about that.  If you ask here, the electrical forum, we'll answer.  One main issue here is that the rally gauges are not an add-on.  A car with rally gauges takes a totally different main harness.  Some of it's a little surprising.  The tach is an add-on but rear defrost isn't.
Title: Re: Main Body Wiring Harness
Post by: roadking77 on June 13, 2022, 11:22:54 AM
I agree completely about the plastic shielding. In my case I checked things over pretty good. Got lucky I suppose.
Title: Re: Main Body Wiring Harness
Post by: roadking77 on June 13, 2022, 11:23:53 AM
Theres another company called 'Ron Francis' that does wiring. I dont know if he does a kit for firebirds. I think he is local to me.
Title: Re: Main Body Wiring Harness
Post by: Dwills on June 14, 2022, 05:42:23 PM
The factory put the harness in the dash and then put the dash in the car.  To me it's easy, but I've looked at 100 of them and I like wiring anyway.  I don't ever ask "what's this plug" in a thread.
(http://www.firebirdtransamparts.com/techinfo/harness/dash1.jpg)
It's somewhat helpful to know what's an add-on, I guess, and not get confused about that.  If you ask here, the electrical forum, we'll answer.  One main issue here is that the rally gauges are not an add-on.  A car with rally gauges takes a totally different main harness.  Some of it's a little surprising.  The tach is an add-on but rear defrost isn't.

So as a product of doing this I assume there are some common points where the harnesses come together,  Do you have a list of these points or are they clearly marked in the wiring diagram?  In the back of my head i knw it but just did not think about it thanks for bringing it up.  That is one of the things I am afraid of ordering on is not getting the correct "options"  in the harness. 


Thanks again to all who have responded

Doug
Title: Re: Main Body Wiring Harness
Post by: Dwills on June 14, 2022, 05:46:29 PM
Theres another company called 'Ron Francis' that does wiring. I dont know if he does a kit for firebirds. I think he is local to me.

Thanks for the reference,  I looked him up and it looks like he does have a couple universal retro kits as well as a chevy kit but nothing pontiac and does not get in to years or options.

Thanks again for the info

Doug