84 to 86 Duke retrofit

[dguy]

Removing the air deflector from the back of the driver's side vent will give you a bit more room to work with.

[dguy]

Remember that fun little junction box (a.k.a. C200)?  Time to play with it again.   

You'll find two 10-gauge wires from the main harness connected to it.  One is pink and is in the top-most position near the rear of the block, the other is orange/black, and is in the top-most position at the far front of the block.  You may need a small screwdriver or similar tool to press the clip which releases the connectors, and a drink or two.

[dguy]

C100 (the pass-through for the front-end wiring) is the same style of beast as C500.

Undo the 1/4" bolt that you can see from the front compartment, and the two halves of the connector will separate.  Now remove the two 7mm bolts from the passenger compartment side, and it's free!

[dguy]

Remove all of the interior pieces which you so carefully and thoughtlessly placed on the decklid the day before, and open it.  Just like C100, undo the 1/4" bolt to separate the two halves of C500.

[dguy]

On the engine compartment side of the main harness pass-through, you'll find a plastic clip which helps to keep it in place.  You may not be able to see it, but it's there, and looks just like the one on the inside of the car for the ECM harness.  Slide it toward the driver's side to remove.  Now grasp the pass-through with thumb & forefinger, and give it a pinch while pushing it through in to the passenger compartment.

[dguy]

C500 is held in place by a plastic carrier which is fastened to the firewall with a single bolt below it.  If you don't remove the carrier, it won't fit through the hole in the firewall!  Pinch the two ears that you see at the non-wire end while sliding the back & the front away from each other.

[dguy]

By now you should have most of the main harness on the floor near the pedals, and the rest of it on the passenger side floor.

While it may not look like it, you do not have to disassemble the remainder of the HVAC ducting in order to remove the harness!

Pull as much of the harness as you can through to the driver's side, coming to an abrupt stop when the firewall pass-through gets stuck between the heater box and the dash support.  Now slide the harness toward the front of the car...  there is a larger space next to the front bulkhead which is difficult to see, but with some patience both the pass-through and C500 can be slid through it.

Now go have a beer 'cause you're half-way there.   

Installing the 86 harness is the reverse of removing the 84 harness.  That's it, that's all.  I'm not going to say anything more about it unless someone asks a question, 'cause there really isn't anything more to it.   

[dguy]

The jack support bracket, re-finished & installed.  Some strange part of me wants to clean-up & paint the rest of the front compartment now.   

[dguy]

...and now a washer fluid resevoir which would make Tim-the-Toolman proud.  Silly thing will take close to 4L of windshield juice when empty.

That's all for now.  Elapsed time to date is just under 16 hrs.

[2ML67]

If you look up under heater box on driver's side you will find a small portion can be removed by unscrewing one 7 mm screw. Remove this small piece and you have easier access to the area to remove wiring. This is also useful to remove when ever changing throttle cables. Dan

[dguy]

If you look up under heater box on driver's side you will find a small portion can be removed by unscrewing one 7 mm screw. Remove this small piece and you have easier access to the area to remove wiring. This is also useful to remove when ever changing throttle cables.

Do you mean this one, or is there another which I didn't notice?

[dguy]

Now is the time BTW, to test what you can before re-installing the interior and making everything harder to get at.  Interior and front-end accessories are easy... install the appropriate fuses, connect a battery to the spade terminal of C500 which normally receives battery power, any necessary switches, and go nuts.

Testing of any of the rear accessories may be partially done by probing the terminals of C500 with a voltmeter, test lamp, etc.

Naturally I have a few bugs to kill before going much further.  The first of which, were always-on courtsey lights.  Simple enough--the driver's door wasn't pressing the switch plunger far enough to break contact when the door was closed.

If you're using OEM pin switches but the rubber "accordion" has long since vanished, you may need to place a 1-1.5mm washer behind the switch before screwing it in place.  This should push the switch's plunger out far enough to make contact with the door, but not so far that anything is mashed unnecessarily when the door is closed.

[dguy]

If the donor car didn't have a remote decklid release, but you want one on the victim car, you have to find the pigtail for the decklid release relay.  It's probably taped up to the part of the harness which connects to the ignition switch.  If you can't find it "at a glance," lower the column again and take a look.

The wiring diagrams I have show that for manual cars (which the donor was in this case) you're looking for a pigtail with grey/black, black/white, and tan/white wires; automagics have a yellow wire in place of the tan/white apparently.

Then you get to the harness I have, which has a yellow/black wire instead of the yellow or grey/black.   

[dguy]

The remainder is easy...  find a spare horn relay that you have kicking about, plug it in to the socket, and mount the thing somewhere handy.  I chose to drill a couple of holes in one of the instrument pod supports & zip-tie it.

[dguy]

Part of the wiper motor upgrade which I forgot to mention, is that you have to replace the wiper switch which hides inside the column.  While the plug from the 84 wiper switch will fit the socket in the 86 harness, they are not electrically compatible!

There's a good reference for a steering column teardown here.  Note that while the article describes working on a column which has been removed from the car, you don't have to do this if all you're interested in is changing the wiper switch.