I bought an 87 5.7 tune port auto and the wiring harness was all cut up both under the hood and dash, would any 86-89 tune port harness work? Also, the numbers on the ECM are worn off, how do I track that down?
Thanks
Spence

 

The ecm service is a 1227165
I think you are limited to 86-87 harness since the alternator is on the passenger side.
Harness lengths are slightly different from birds to camaro.

 

Best to stick with 87 harnesses for the ENGINE, preferably from a Camaro. 88+ harnesses are very different and 86 down used large 'coil in cap' Distributor and the older style Alternator.

86 & 87 ECM ( "TPI") harnesses should be VERY similar ( if not the same )
** Make sure the ECM harness you get is for made for an AUTOMATIC if you have an 700R4 !! )

The DASH wiring harness would be best matched to an 86-87 Camaro,....... 85 & 88 ( + 89?) will work with some minor changes.

 

 

 

There are wires cut all over this harness under the hood and under the dash, it is crazy. Since the middle part of the dash was broken, I decided to remove it today to easily install the new harness. I am not sure why the cut the hell out of everything but man, lots of work!

Thank you for the responses btw, very helpful!
Spence

 

That's a basket case. You could a) try to fix what's there, b) find exact donor parts, c) toss nearly everything and use a complete set of donor parts from another car. None of the above is really cheap or easy. If you are comfortable with auto wiring, you can probably fix what's there, but most people will be further ahead with a donor car

 

I am actually ok either way, I have the FSM and the electrical supplemental manual but my issue is most of the plugs are missing. I am probably gonna splice were I can from a donor harness. There looks like under the dash some type of alarm was installed. Lots of stuff cut, lots of wires chewed on too. If this car didn’t have such good RPO codes and body, I would probably have parted it out.



Other than this dent on the quarter, the car is super straight

 

Mouser carries most of the terminals and connectors. Can find better than stock grade automotive wire in GM colors on Ebay. The worst part of sourcing all the bits is the fouled up catalogs. Packard Electrical being absorbed into Delphi, Delphi's divorce from GM, rebranding as Aptiv, etc has made the catalogs and Mouser links into a mess of "Page not found" errors and other dead ends.

 

The plug up on the driver’s side firewall is chewed up but at least traceable. There are about 10 wires cut off at the battery. That’s my biggest concern.

I have a wiring harness off of an 86 Hyrock with a carb but I’m not sure that would work for the plugs down by the battery I doubt it.

 

The wire colors should help narrow it down. If you're not sure, just ask

 

Will this work to include the cpu?

Mass air TPI wiring harness, ecu hypertech prom for a 87 305, harness is from a 87 iroc..

I have a 350 TPI 87 Iroc

thanks

 

You will need to get the appropriate memcal or have yours reprogrammed if you have a 350.
some of the Hypertechs can be reprogrammed if it has a black goo on a circuit board on the back half of the memcal its not reprogrammable.

 

Ok that’s good to know, maybe I’ll tell him to keep the prom since mine is probably fine. The harness is my concern and so if that works then I’m happy!

so far I have found from an 87 iroc
- full under dash harness: $30
- full engine harness (with that other prom): $150
- full headlight harness: $30

i am thinking I might be heading in the right direction. Anyone free next week for a wiring party? 🙂

 

Sounds like a good plan. You might have to replace some of the old connectors on the harness. Delphi or packard on eBay or mouser.com is where they can be found. Ofthen the fuel pump pigtail is frayed and converting to 89 up relay and plug is a good idea.

 

Thanks for those tips. I did not know about the 89 connector so that I’ll definitely do.

i plan to start at the plug on the drivers side firewall and disconnect old connect new as I work around to the battery. Then I do the same inside starting with that corresponding omg on the inside of the fire wall.

any other upgrades I should do be for I put the dash back in?

 

I think the fuel pump relay would be the only mod I would do.
the same pigtail or connector was used for 90-92 fan relay.
call efi connection for a pigtail or they sell the connector and terminals a better cleaner way to go.
the cavity’s and relay are labeled iirc should just have to match the letters and wire locations.
you can also do this for the maf relays but they tend to be good and don’t have much issues.

 

I will be replacing steering column, middle dash, and new harness this Saturday hopefully.. Harness I won for 20 bucks off of ebay. Column I have on parts car, and middle dash is 100 delivered. I have one of those on my parts car but I would rather spend a 100 on one that is already out than pull another one of those SOBs! I'll have about 130 in all of those parts. FSM was a good buy too.

 

New harness is in. Looks good with the exception of what I believe are the radio wires.

 

I battled the elements today in PA and got the old harness out. It was quite a rats nest! I didn’t realize how busted up the steering column was too. Not sure if I should repair or replace it.

 

I put my engine in and took the trans out then put the trans back in but no power the battery is charged but no power even with the door open the light would cone indent know if I put a wire in the wrong place I dont remember were all the ground wires were and were they went please help if any one has a pic were the ground wires go will helping have a85fire bird trans am with a 305

 

Just a quick question, will an 1985 TPI 350 Auto IROC engine harness work on my 1987 TPI 350 Auto IROC?
thanks!
Spence

 

A 85 harness can be made to work after repinning for the 165 ecm and adding a relay.
Better off finding a 86-87 harness.

 

+1

For plug-&-play; you'd have to use the 85 TPI ECM if you intend to run the 85 TPI ECM harness.

For the record,..... no GM 350 TPI in Thirdgens till 87. ( That 85 TPI harness is either from a 305 Thirdgen or a Corvette. )