OBD2 swap in older car

[3100 MPFI]

I think I like wiring more than just about anything else. That seems to be the thing that requires the most thinking.

At any given time, I have 5 different service manuals spread out trying to solve some of the more interesting issues.

I have a 1988, 1989, 1993, 1994 and 1996 service manual trying to figure out what wire goes where, how does it work, how is it ran, and what does it do.

I have seen some stuff that made me flat out LAUGH. Like the wiring for the HORNS in the 1996. From interior to drivers side exterior to interior, to passenger side exterior, across the front and right back to the drivers side.

The good news is, with as much reading as I have done with this, I have reached the point where I can just hear a connector or passthrough name/number, and know right where it is, and what it is for. At least, in the W-bodies, that is.

[CobraCDR]

Tat you must realy love that gold car to go through ALL this trouble. I commend you, that is a lot of fuggin work to do. I hate wiring but you love it I Guess! Good job.

[3100 MPFI]

Got an update for all of those keeping an eye on this.

First of all, the last couple of days I have been helping a friend out with some stuff. Saturday, I went to a TOOL AUCTION and got some new things to help me in my quest.

This is the stuff I picked up at the auction.

First of all, I got an old stacking toolbox. It looks bad, but it is really in good shape. It is mostly just sun faded, and it is missing one handle, and does not have any keys, but that is nothing major to deal with.



I needed a new soldering iron, and ended up getting 2 of them. This is an OLD one, and I have not yet tried it out.





This was a BRAND NEW soldering iron that was still in the plastic wrap. I have never heard of this brand before, but after only 2 wires, I think this is the BEST solding iron I have EVER used. And I got it for only $20.00





And one of the things that sold me is that it will get so hot that the tips will turn RED HOT.



Next, I needed to finish bolting in the front drivers seat, so I had to use a makeshift power supply to move it back.



The makeshift power supply was a TIRE INFLATOR that has a 12 volt cigarette lighter port. I just jammed a wire in there, and grounded the unit to the car, and that gave me the needed power to move the seat back to bolt it in, then forward to tighten down the rear bolts, then back again into place.

Not pretty, but it works.



The next thing I did was remove the old front light wiring harness from my 1996 Grand Prix MKE parts car. I needed to get them out to compare some stuff, and to also get the rear air vent duct for the PCM box.





Getting that harness out let me figure out how to do the rewire to my stock harness. This is the forward light harness with the plug wires swapped out, and ready to go back in.



And here it is reinstalled in the car.



The last thing I did was work on getting the PCM box back in place and everything fitting in there properly.

Here is where I had to cut out some of the stock setup fender material so that the backing plate would sit all the way in place.



Next, I ran the 2 air ducts, and connected them



Finally, the backing plate was in place



And finally everything all the way back in with the exception of the cross car brace. I have not put that in yet seeing I have to remove all of this when I put the engine in.



And lastly, I finished wiring in the drivers side electrical center. I had to do some work for the FOG LIGHT RELAY seeing the harness I bought was from a REGAL, so it does not have the wiring for the foglights. I also rewired the horns.



I made some changes to the way the wires wree ran. I need to start writing down the specifics in case I ever need to remember some of this later on.

[3100 MPFI]

Since I posted this, I found my 1991 ElDorado book, and it covers the Autodimming wire, I was going to take the overhead console out because I have 1 of those wires spliced into the HOT IN RUN that is up there.

Now that I have the caddy book, I don't need too. I had the pinouts for the mirror.

[CobraCDR]

Tat just grab one blue wire and probe with one end of the meter, then go up to the harness where the mirror is and use the other probe and pick one of the pins. Use the continuity check function and when it beeps you know which wire is which. That might be easier than tearing the overhead console out. Those things are a pita.

Ken

[3100 MPFI]

Finally reached the point where the car could be moved into a better place to work on it.

I can't work on the cars at my house. The landlord will not let me. I have to do everything down at my parents house. Today, I went down there and cleaned up her carport (my sister-in-law has a lot of crap under there and it was in my way). I finally got the car up under there (had to push it). Now that it is under there, I can get started on the GOOD stuff.

This is where the car had been sitting. As you can see, it was there for a LONG time.



Here it is under my moms carport. All of that crap along the drivers side is my sister-in-laws crap. She does not have room for it at her house, and she does not want to pay for a storage building, so my mom got stuck with it.





Now that the car is under the carport, I need to do some more wiring. I have a few things to figure out, and now that it is under here, I can jack the car up to get under it. Here is what I am starting out with. The main part of the OBD2 conversion has been done. I am now just working on the stuff that is different between the 1988 front light wiring harness, the 1994 dash harness, and the 1996 engine harness.



The first main modification I have made is to remove the studs circled in red, Those are what hold the old ECM in place, and the wiring harnesses and stuff. I have to use the newer coolant recovery tank, so I had to remove these for it to sit in place properly.



That is about it for now. Tomorrow, I hope to get the engine wiring finished, and can start on getting the transmission back out of it. I have to swap out the bracket (the 1996 bracket is different than the 1988 one). I also MIGHT have to drop the subframe, but if I can get away with NOT doing that, I don't really want too. It is 40% chance of rain tomorrow and suppose to stay that way throughout the week, and weekend. At least now the car is covered.

[3100 MPFI]

I ALMOST have the interior finished now. I got the dash pad back in, but I still have some finish work to do, as well as a LOT of cleaning.



Of what I still have to do:

I need to solder in those 2 blue wires. They are for the AUTO-DIMMING mirror. I am not sure which one is which, so I need to pull the overhead console to trace them. That is why I didn't do them already.



I also have to finish up the underside of the passenger side of the dash. That GRAY wire, and the RED wire, those are for the heated mirror, and will actually be hooked together. I was originally going to do the power supply wire outside of the convenience center, but I decided last minute to do it on the inside of the convenience center. I also need to do that one connector. That is the connector for the lights under the hood, and stuff. I have to figure out some things first.



This is the underside of the drivers side of the dash. I THINK I have it almost done. I think all that I need to do is the connector for the trunk release, the ALDL connector, and the STEERING WHEEL controls.



This is just a shot of how the car was when I left it. I think with the stuff I just mentioned, I also need to put in the drivers seat, but it is POWER, and I don't have a battery in the car right now.



Notice, the dash is FLAT. No warpage here, yo!

[3100 MPFI]

Even though the weather was bad (had a coldfront come in, and it was raining), I did manage to get some things done. I got over there and pulled the steering column and theft deterrent module out of my 1995 Cutlass Supreme to use in my 1988 Cutlass Supreme.

First of all, I finally had someone in the car with me doing all of the praying. That gave me more time to work on the car with him doing all of that heavy praying for me:




I got most of the stuff on the underside finished. All I need to do now is solder in the ALDL connector as well as the power trunk release button. I also have to do some ground wires. I don't like where they were, so I am going to move them:



I installed the 1995 steering column. There is only ONE issue with it, but is really minor. The TILT STEERING LEVER is different. When the steeringwheel is down, it ALMOST touches the air vent:



The radio is in, as well as the steering column and steering wheel:



I refinished one of my older secret mods. I installed a LIGHT inside the center console that comes on when you open the lid. That REALLY came in handy at night:

Here you can see the on/off button on top by the hinge, and the hole for the light itself:



This is the light that I used:



And here it is fully installed in the car:






As promised, here are the comparison pics of the BUICK REGAL top console piece, and the Cutlass Supreme top console piece.

Side by side:



bottoms:



tops:



For shits-n-giggles, I decided to do a little work with the dremmel.

First, I cut off the extension part for the Regal storage bin:



After a little smoothing, and sanding (still need to do some more), I tried it out:



ehh. Why not?




It's kinda growing on me..... Like MOLD:






Sorry I didn't get any pics further away. It was raining Cats and Hippo's and I didn't want to open up the door just to take some pics.

[3100 MPFI]

Thanks Kenny.

[CobraCDR]

Looks nice tat glad to see work is progressing on the gold car.

[3100 MPFI]

nahh. It is a labor of LOVE!!!!!

[JMo60]

wow that is one major undertaking.. looks like a PITA

[3100 MPFI]

I am only on the forums at night. Sometimes, family keeps me too busy to do anything. I also get distracted when I want to do something different (like the short shifter).

In the end, I think all of this is going to be worth it.

[IsaacHayes]

Neat. Keep at it. Less time on the forum more work! haha

[3100 MPFI]

Got a LOT done today. I had a day where I was left alone, (thanks to turning my cellphone off), and I was able to bust ass. I even got one of my SECRET PROJECTS done, and am showing the results here for the first time ever.

Here are the pics.

I got the covers back on the rear speakers. I need to replace the matrial. It has faded from a nice BLACK to a light gray. Damn Texas sun.


This is close to what I started with this morning. The carrier was down on the floor. In that pic, there was only 1 bolt holding the whole carrier up. That new harness was so much thicker that it was a harder fight to get it in place, but I finally won.


This is the AMP, FOGLIGHTS, and TRUNK RELEASE wires. I still need to solder in the trunk release but I have something special in mind for that. You can also see the stock amp tucked in behind everything.


This is the digital climate control wiring, as well as the radio wiring.


CLUSTER, and HUD wiring.


DIC, and HUD wiring (HUD is the LIGHT GRAY wires going onto the floor). The wires that are just hanging there, those are for things that I might want to add in later. Like the BTSI, and the E/M, and stuff for the center console, like SGS.


The headlight connector:


This is the mess under the passenger side that I had to go through. As of now, the only wires I have left to solder under there is the wires for the HEATED MIRRORS.


See the metal box with the green thing in there? That is the PASSKEY2 module for the 1994. It is tucked way up under there on the left side of the brake pedal support. I think that was one of the more PITA things to do.


instrument cluster back in place, as well as the HUD bracket.


a PERFECT top to my center console, as well as a good drink holder. Talk about RARE!!!!!


The underside of the drivers side. I still need to do the ALDL connector (which I LOST). I also need to get a steering column. Tomorrow, I will get that in, as well as the brake booster so that I can get the underside totally sealed up.


The milege on the cluster. 328676. That is original to the BODY.





Finally onto the juicy stuff. This is the beginning of my SECRET PROJECT, as well as some of the wrap up on the interior. Here is a good INTERIOR SHOT as the car was today when I left it.



One of my biggest complaints was about how tall the shifter is in the Cutlass Supreme. It is not as bad as the Grand Prix (which are really the same height, but the Grand Prix console sits lower). When I was removing the interior, I acidentally pulled an extension cord across the shifter, and it broke the plastic pushrod off, so I decided to shorten it some. I also decided to use my spare leather CORVETTE shifter knob. It looks REALLY GOOD in there.

Here is a side by side comparison of the stock shifter, and my new short one.


and a front and back compare. The short one is in the front, and the normal one is in the rear.


And here is some closeups of it installed in the car.

PARK:




OVERDRIVE:


and FIRST:


If I didn't know any better, I would swear that I PLANNED it this way.