Convert 85 turbo z t2 glhs style wiring to 89 t2 shelby daytona wiring

I have a 85 turbo z that the wiring was modified to run off a 86/87 glhs style lm and pm set up. I have a full body running 89 shelby with a 2.2t2 and 5spd trans. Only things i can really tell that are different from interior wise is the 85 is power and the 89 is manual windows, locks and seats. If there a way to modify the 85 wiring to run the 89 electronics and still keep my power interior?

things to know about your wireing

84 is unique
85 and 86 are basically the exact same thing .. EXCEPT they used a bunch of new style connectors throughout the car starting in 86-89

so the wireing in both cars will be much the same from the dash back except the 85 stuff likely will have issues pluging into the 89

in most or all cases of the interior/body wireing from the dash back you should only need to splice on the FEW different connectors

unfortunately you may not have the connectors you need to splice on in the 89 (you may)

the door wireing is one harness - it runs from the driver's door across under the bottom edge of the windshield behind the dash , DIRECTLY to the opposite side of the car and into the pass side door

the door harness plugs into the dash harness at both sides of the dash

there is a 25 way connector at each end of the dash and a few connectors inside each kick panel
- this is where the body wireing plugs into the dash wireing

plugs for the cluster and mesage centers will be different on the 89 dash harness

tail lamps , fuel pump and power seat should be connected at the driver's end of the dash

console I believe is connected at the pass side of the dash - I forget what else may be pluged in on that side working off the top of my head , sorry

It was wired to run an 88 dash and speedo sensor on the trans, not the cable driven 85 dash. The 85 has been running the t2 all along but i think there may be more options open to me going 89 electronics. Do the bulkhead connectors have a different number of cavities 85 to 89?

you would have to check the bulkhead connector in the 85 - it may only still be a 40 way connector

also the bulkhead connectors under the 89 dash are reversed compared to the 85-7's

also as the bulkhead connector got reversed and moved under the dash the stoplamp connector got moved
it runs through the bulkhead connector "forwards" to the brake pedel
so .. the brakelamp switch connector is actually on the engin compartment harness in the 89 rather than on the dash harness in the 85-7

that should eliminate some confusion when looking at the pin outs for the 85 and 9 bulkhead connectors

(an 86 would for sure have a 50 way bulkhead but I'm not sure about the 85's)

I found everything electrical got much better after 85 so using as much 86-9 stuff is a good bet

Sounds like a huge headache to do this when i have a car wired to run already and probably just needs a new calibration. I dunno it would be great if it was easy

If i took it all out, i mean everything, could i completely run the 89 harness if i cut a hole in the 85s firewall to get the 89 harness to mount exactly as it sits in the 89 shell i feel it would be easier than mateing the harnesses. Id probably have to change the headlight and taillight witing to suit the 85 and other minor things.

that would be the best way

the hole in the firewall - if you measure the male half of the 50 way bulkhead connector , diagonally corner to corner , you will get the size the hole for the gromit needs to be

the changes in the connectors that would need delt with would be a few in each kick panel for the rear wireing

also so you know , the gromit in the front of the doors for the wireing going into the doors is larger in 84/5 than the 86-9 cars - so you're better to splice on the correct connectors rather than swap the door wireing harness
- or you would have to swap the 85 door gromits onto a newer door harness and plug that in

I've done this swap. The way I approached it was to laid out the 89 front engine compartment harness on a bench, remove the split loom and remove the circuits that I wasn't going to use from it like lightning. Next I removed all of the split loom from the engine compartment wiring (harness still in place) and remove the engine management wiring but left a few feet of wires coming out of the bulkhead. You also need to remove the vacuum solenoids, MAP sensor, starter, radiator fan, and A/C clutch relays from the car. Next start installing the 89 wiring. Connect everything to the engine and peripherals first, with the 89 solenoid's and relays plugged in attaching it to the 86 harness. There's only a handful full of wires from the 89 harness that connects to the 86 bulkhead wires and mostly it's color for color. You also need to supply unswitch power to the SMEC and ASD relay power from the fuseable link that once used to power the old PM/LM setup
The 89 combination oil pressure sender won't work with your 85 dash gauge so you need to keep your 85 switch and sender. I did this swap 8 over years ago and I'm sure I've left a ton of stuff. I remember the wiring in those harness was a lot longer than they needed to be. So you can shorten them up.

Its an 85 so not sure if that makes a difference Marc far as the harness 85 to 86 them to 89 like you did

Should be the same. If you decide to go through with the swap I be willing to give you my phone number and I can take you through it each step of the way.