87 wiring - The 1947 - Present Chevrolet & GMC Truck Message Board Network

xs-style · 09-05-2019, 05:10 PM

Does anyone know of any suppliers that sell factory replacement harnesses for everything from the fire wall forward on an 87?

**MikeB** · 09-06-2019, 03:51 PM

American Autowire sells a stock replacement engine harness. I'm not sure if that gets you the lighting harness. Give them a call, they are very helpful and their products are first rate. They are Number 1 or 2 on my all-time favorite vendor list.

https://www.americanautowire.com/shop/factory-fit/

Nachos82 · 09-12-2019, 12:30 PM

I got a factory style firewall forward light harness from gmachinz on here. All the wire/sockets look like/are the factory style.

I would hit him up and see if he can make what you are looking for.

**hatzie** · 09-14-2019, 11:30 AM

There are several harnesses and parts of harnesses that terminate at the firewall in the engine bay.
By 1987 they were complex enough that the one-size-fits-all harnesses weren't really useful. IMHO

Forward lamps and horn.
Engine sensors and ignition.
Alternator.
Heat/AC.
Main power.
Fuel and fuel level.
NL2 dual tanks if equipped.
Transmission TCC and or kickdown.
Rear lamps.
Wipers.
If I'm repairing a rear lamp harness I add a 12ga Blue Trailer brake and 12ga Orange trailer battery wires to the four lamp wires and I upgrade the earlier molded connector to the square 2x2 four position Weatherpak that GM used on the 1984 and newer trucks.

How bad is the original harness? Wire jacket cracks and such?

I usually separate the sub-harness in need of TLC from the chassis and lay it out on a sheet of plywood on sawhorses
Once it's laid out I replace the damaged wire or damaged terminal with a new wire and terminals. Do this one at a time with the same or adjusted length of new SXL wire & brand new Delphi (Aptiv Automotive now) terminals.
I replace the wire covering with new pieces where needed. The tape is harness tape not electrical tape. Black split poly loom is easily available from NAPA in shorter lengths along with 100' and 250' spools. I try to be fairly careful of the wiring clips and poly loom Tees and such as I don't have a decent supplier for small quantities, less than 5,000 or 10,000 order size, of these.
I try to re-use the original Delphi connector shells wherever possible.

There are several Delphi wiring booklets that I scanned in the manuals post.

09-05-2019, 05:10 PM	#1
xs-style Registered User Join Date: Mar 2008 Location: Lawndale, NC Posts: 658	87 wiring Does anyone know of any suppliers that sell factory replacement harnesses for everything from the fire wall forward on an 87? __________________ 1978 Scottsdale - celebrating 10 years of teaching me profanity 1990 Silverado - bought in Nov. 2016 and it's already catching up - Sold 1987 k5 blazer - sold... :\ seed money for the 81 1981 k20 4x4 - 5.3 swap in progress Events attended: Spring GOG 2011 Dale JR car show Summer 2012 Gathering at Tommys pickup parts

09-06-2019, 03:51 PM	#2
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,597	Re: 87 wiring American Autowire sells a stock replacement engine harness. I'm not sure if that gets you the lighting harness. Give them a call, they are very helpful and their products are first rate. They are Number 1 or 2 on my all-time favorite vendor list. https://www.americanautowire.com/shop/factory-fit/ __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

09-12-2019, 12:30 PM	#3
Nachos82 Registered User Join Date: Feb 2007 Location: Central Florida Posts: 166	Re: 87 wiring I got a factory style firewall forward light harness from gmachinz on here. All the wire/sockets look like/are the factory style. I would hit him up and see if he can make what you are looking for.

09-14-2019, 11:30 AM	#4
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: 87 wiring There are several harnesses and parts of harnesses that terminate at the firewall in the engine bay. By 1987 they were complex enough that the one-size-fits-all harnesses weren't really useful. IMHO Forward lamps and horn. Engine sensors and ignition. Alternator. Heat/AC. Main power. Fuel and fuel level. NL2 dual tanks if equipped. Transmission TCC and or kickdown. Rear lamps. Wipers. If I'm repairing a rear lamp harness I add a 12ga Blue Trailer brake and 12ga Orange trailer battery wires to the four lamp wires and I upgrade the earlier molded connector to the square 2x2 four position Weatherpak that GM used on the 1984 and newer trucks. How bad is the original harness? Wire jacket cracks and such? I usually separate the sub-harness in need of TLC from the chassis and lay it out on a sheet of plywood on sawhorses Once it's laid out I replace the damaged wire or damaged terminal with a new wire and terminals. Do this one at a time with the same or adjusted length of new SXL wire & brand new Delphi (Aptiv Automotive now) terminals. I replace the wire covering with new pieces where needed. The tape is harness tape not electrical tape. Black split poly loom is easily available from NAPA in shorter lengths along with 100' and 250' spools. I try to be fairly careful of the wiring clips and poly loom Tees and such as I don't have a decent supplier for small quantities, less than 5,000 or 10,000 order size, of these. I try to re-use the original Delphi connector shells wherever possible. There are several Delphi wiring booklets that I scanned in the manuals post. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

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