'93 Burb harness/ECM removal - Warn me...

[newyorkin]

I'm going to the wrecker in a few days to pull the harness and ECM from a '93 Suburban to use on my '93 Caprice motor. I'm going to convert my '85 K20 to the TBI motor.

I looked at it today, and the way the bulkhead is mounted under the AC dryer looks like a hassle to get to. I can't damage anything on the truck as I pull it apart, or I have to buy what I damage.
This yard is giving me the harness and ecm for $100 if I pull it myself. I want to be able to get this thing apart fast, since I'll pretty much be on my lunch break.

So any warnings? Snags I'm going to hit?

 

[dyeager535]

Is there no way you can get one from an earlier TBI truck?

I can't imagine if the truck is fairly complete, that an hour is going to be enough time to deal with getting all the wiring out in good shape, and no point in doing the work if you end up cutting stuff to get it out.

Assuming you are taking the whole fuse panel on the inside, since that will be tied into the ECM, there is going to be a lot of work tearing the interior apart. If you can, and go back and re-evaluate what you are getting into, make sure you can really get everything out in an hour.

I'd leave myself more time than that for even a 1981-87(91) C/K/R/V if I wanted it out in good shape, plus won't hurt to label things as you pull them, unless you've got the GM manual for a '93, as there are going to be all sorts of connectors you won't be using and will have to figure out which wires do what and so on...

 

[newyorkin]

OH, right, I forgot about the fuse block... I had planned on the aldl connector, so I knew I had to cross the dash for that, but I didn't know the fuse block was tied to it also.

The engine is out of the truck already, so it's 90% hanging.
I may just be buying the whole thing from a member here instead. I have some financial waters to navigate around my wife, then I'll know which way I'm going.

Thanks Dorian.


There may be one available somewhere from an earlier truck. The one I may be buying from the member is from an '89 I think.

 

[dyeager535]

IMO you are just better off buying something complete from one of these trucks. I would expect the newer trucks (like the '93) to not nearly be as monkeyed with wiring-wise, which is a huge plus in my book, but still, the older setups can be found unmolested, luckily people either are scared to touch it and leave it alone, or they cut it out and put a carb in.

My TPI setup was from an '88 Camaro, and the wiring differences were immense due to the different application, even though the fuse panel and what not would have been quite similar.

It is a cleaner install swapping the fuse panel as well, since you don't have to worry about independently fusing everything like the two injector leads, ECM, etc., GM has done that for you already.

 

[newyorkin]

Yeah, getting the block sounds cleaner, too. From what I saw, there's going to be a TON of stuff on the harness that I just won't use. I don't care if I cut and tape it off, or even just tape it off. Cosmetics are not an issue to me with this truck...

I considered TPI, but it looks like more time than I want to spend on it. In the end, I may sell this thing the day I get the title, so I don't want to go crazy. $100 and a little elbow grease is worth it to me, but $100, a dozen and a half "aw crap"'s, and something fairly unfamiliar to me (TPI) is not worth it...

I was also looking into swapping a carb intake onto the '93 motor and just moving the carb over, but the more I drive it, the more I remember how much I hate carbs on a 4-wheeled vehicle...

 

[Russell]

I can throw in a positive reply for you.

The wiring in my old 77 stepside came directly from an 89 2wd 1/2 ton truck. Removing it was a breeze, only wires that gave me some trouble was the AC stuff and the fuel pump wiring.

I didn't use the factory bulkhead connector and just ran all the wiring through the same grommet as the heater box wiring goes through. Removing the wires from the connector was a HUGE pain in the butt though, as all the wires are hot-glued in. I cannot think of a single reason why you couldn't use the connector though, unless you are scared to cut big holes in your truck like I am.

Under the dash there is a connector that runs off to the driver's side of the truck with the ALDL wiring, power feeds, park / neutral signal etc. I just made up that part of the harness on my own with connectors from the junkyard and new spools of wire rather than trying to tear the dash of the donor truck up.

In my 77, I didn't have to cut any wires less a couple AC wires, and the fuel pump wire that ran to the pump itself.

There are wiring diagrams at www.chevythunder.com -- Just look for the 7747 ECM.

This is all assuming that the 93 still has a 700r4 though, if it has an electronically shifted transmission, I can't say for sure that the wiring will work for you.