skinny z

I'm reworking the wiring harness (finally) and have long since swapped to a non AC heater box. The wiring side of things is easy, it's the routing that I'm curious about.
Does anyone have any pictures of how the loom is routed in and around the heater box?
I have the main engine harness to deal with, (with power from the starter terminal and other accessory circuits) which ties into the wiring that's to and from the battery as well as drivers side electrics and C100, and also the harness that's dedicated to the blower controls. At least I think there's a separate harness for that.
Any pictures would be appreciated. I'd also like to see the routing in and around the brake booster and firewall bulkhead connector (C100).

Drew

iTrader: (58)

It's somewhat important to note that different years are wired and routed differently. You'll want to use a very similar car as a guide.

For example, early TPI cars have the injectors in one loom, and the alternator wiring in another. Early cars have the fog light wiring on it's own or wrapped with the cruise control wiring, while later cars have the fog lights wired into the headlight harness. Then there are all the details that changed over the years, different fuel systems, etc.

If you have access to a GM Service Manual for your car, there are general diagrams in the electrical section that show where various harnesses route approximately, along with specific diagrams of various parts that show the general wiring routing.

Mark_ZZ3

It would be a nice sticky to have each year photographed. I was trying to sort out my 1989 ... had to look at a few pics to figure it out ... still not 100% but close.

Mark.

skinny z

I'm not trying to be all that specific. It's really just the harness the supplies the non AC blower that I'm looking for. Having swapped out my AC many years ago I'm a a bit of a loss as to what the factory had in mind.
My GM service manual (1987 Shop/Service manual right from GM) has a few very nice illustrations of some of the harness' in the vehicle. Unfortunately, they don't cover the engine compartment with as much detail. And what there is, covers the AC application only.
So...still looking for pictures.

skinny z

That would be handy.

paulo57509

I've looked through my copy of the '86 Assembly Manual and thy really don't show the harness routing, etc. for just a C40/C41 car. The engine harness drawings just end in a connector labeled "To AC Harness".

There's no drawing for the AC harness. Also, the engine harnesses differ between LB8, LB9, LG4, Iron Duke, etc.

It appears that the engine harnesses end in two connectors for the HVAC; the AC harness and a Power Feed connector. I think you can make your own harness using these two connectors (provided they're still there).

FWIW, I've attached drawings for the LB8 and LB9. There's no right side engine harness drawing for the LG4.

skinny z

Thanks for that Paulo. However it looks to be the AC version where I'm after the non AC installation. I was interested to seen how the factory routed the loom through the engine bay.
As it is, I've completed the wiring and I'm sure it's no where near what the factory intended however the installation is tidy and I suspect functional.
I'll post pics of my handiwork when I'm back in my shop in the next couple of weeks.
Thanks for the input everyone.

paulo57509

You're very welcome.

FWIW, RPO C40/C41 are heater only options.

skinny z

My mistake Paulo.
I saw the AC connector in the harness wiring and made a hasty assumption. Those illustrations ARE what I'm looking for. Those drawings and the one that shows the blower motor harness. It's a separate chunk of wiring that passes through the firewall from the interior (behind the right side cylinder head) and makes it's way over to the resistor bank for the blower motor. I can't tell from the drawing if it's in there or not. It's definitely not part of the V8 harness drawing.
From the looks of things, my routing is a little cleaner than the factory's. I've kept the loom below the heater box and eliminated the connector that's pinned to to the top of the firewall.
Thanks again.