84 to 86 Duke retrofit

[dguy]

Where to start?

We purchased the parts car mentioned here.  That thread also explains why we're performing this upgrade in the first place, if you care to read far enough along. 

First things first.  As we had no clue when the donor engine was last run, I decided to bench test it.  Naturally a bunch of components were... tired after sitting for a year or more.

• nearly-seized starter motor, with a cracked mounting ear;
• mouse-eaten spark plug wires (I'm serious!);
• disgusting cap/rotor, weak pick-up coil;
• gummed up TBI & fuel pressure regulator;
• rotten coupler between fuel pump & output line;
• muffler full of sound deadener.

...and it works!  It still needs small handful of little things looked after before installing it, but I was impressed once it fired up.  No unusual mechanical noises, and smooth as glass when running.

Note to prospective followers of my bench testing method--a $20 box fan from CTC does not move enough air over the radiator to keep the engine at a decent running temperature for more than about 15 minutes.   

[dguy]

The real work started yesterday.  To complete the illusion, why not exchange that puny little washer bottle and the funny-looking jack for those from the '86 as well?

[fiero308]

ok, I can't resist....
I see the 'box' with "LT" on it.........
Don
are you putting in a chev 'crate' (sorry  ) engine!?!?!??!?
wow; I'm impressed.

LOL
nice to make some progress while the weather holds.
good for you

[dguy]

Fitting the 86+ washer fluid bottle is as simple as grinding off the lower mounting stud which was supporting the 84/85 bottle.  Cover the bare metal with paint, seam sealer, etc. once you're satisfied with the stud-ectomy.  Make sure that it's flush with the wheel well, and burr free.  A few thousand kilometers later & a few rough edges could rub a hole through the "new" bottle.

[dguy]

I see the 'box' with "LT" on it.........
Don
are you putting in a chev 'crate' (sorry  ) engine!?!?!??!?

Boo hiss.    LT-5 is the fifth crate we have that's full of lighting & electrical components.  We may actually have exceeded the volume of Gary's parts collection at this point.   


Here's the support for the 85+ spare tire jack, which is going to spend some time in the de-ruster before it gets attached to the car.

[dguy]

Wiper motors...

You probably don't have to do this if you're in the technological dark ages and don't have intermittent wipers to deal with, as all 84's had non-delay wiper motors on the "outside."  The 84's which had the delay wiper option have a timing module burried in the interior wiring harness; 85+ models with delay wipers used a different wiper motor with a timing module which was part of the motor.

The pic below shows the (84's) non-delay wiper motor above, and the (85+) delay wiper motor below.

[dguy]

Switching the wiper motors is as simple as removing the cowling, unbolting everything...

[dguy]

...and then putting it all back together with the new motor in place of the old.  Nothing to worry about with the wiring--the pigtails for the delay vs. non-delay wiper motors are identical.

[dguy]

Remove the interior.  All of it.  Unless of course you opt not to install the 3rd brake light, then you can leave the headliner board in place.  In any case you'll likely find that it's much easier to do what you need to do if you don't have to work around trim panels, carpet, etc...

[dguy]

In the interest of not upsetting the Ministry of Transportation, and not relying upon memory when it comes to renewing licence plate permits and declaring the correct mileage, we move the odometer from the 84 instrument cluster to the 86 instrument cluster.

Note that this is a very complicated procedure, and should not be attempted without an assistant.

[dguy]

Try to pretend that you're surprised when you find that one or more of the floor pan "drain plugs" have rotted away.     At least the damage was limited to the plug this time, instead of taking part of the floor with it.

[dguy]

Hole?  What hole?

[dguy]

Now the fun begins. 

I decided to tackle the small, "intermediate" portions of the interior wiring before doing the main harness.  First to go was the wiring for the 84-85 door ajar switches, and the courtsey light pin switches.

The 84-85 cars have pin switches above the striker bolt which operate the "ajar" light.

[dguy]

86+ have the ajar switch inside the door, attached to the latch.  The black two-wire connector shown on the left connects to a corresponding pigtail which comes in from the switch inside the door.

I'll take apart the doors to install & connect the ajar switches later.

[dguy]

If the victim car has different accessories than the donor car, be prepared to spend some time unwrapping 20-year-old electrical tape so that you can separate circuits which were run in the same loom.

For example, our victim has power windows & mirrors, the donor had power nothing.  The lines for the RH power window were taped up in the same loom as the ajar switch/courtsey light switch lines...  old electrical tape is very sticky, trust me.  Rather than follow in GM's footsteps, I used zip ties to reconstruct the looms.

Below is a progress shot: the three white & one black/orange wires on the left are the original ajar/courtsey switch wires, the taped up loom on the right is the "new" ajar/courtsey switch harness, and the pink/blue wires running left-to-right above are the lines for the RH power window.

Near the top left, you'll see a white box with a boatload of wires going in to it.  Unless you have hands the size of a 10-year-old, or a handy 10-year-old slave, you'll love to hate this thing.  It's basically a junction box which connects a number of the accessories to the main wiring harness, conveniently placed in a nice, easy-to-reach location.  Not.   

When dealing with this junction box, I strongly recommend only unplugging the circuit(s) you're working with at the time.  Given its location & visibility, you don't want to lose track of which connector goes where!  While the connectors do appear to be keyed, I'm not brave enough to unplug all of them at once and determine whether or not each keying is unique.