Heffy Posted December 3, 2019 Share Posted December 3, 2019 Hello I must replace the main ignition module wiring harness on my 91 Reatta. I can not find a part number or a source of the part. I would appreciate some information if anyone has an idea. Thanks Link to comment Share on other sites More sharing options...
2seater Posted December 3, 2019 Share Posted December 3, 2019 Are you asking about the small harness at the pulley end of the engine that connects the cam, crank and knock sensor to the ICM? The only source I know would likely be the pick a part yard. The 1990 has the same harness and I found a similar one on the 1995 s/c engine I have (not verified it is identical), so the range of possible donors should be large. Earlier models from '89 and back have a different wiring scheme. Link to comment Share on other sites More sharing options...
Nittany Posted December 4, 2019 Share Posted December 4, 2019 (edited) Heffy, Have you reached out to some of the Reatta vendors who make parts available for our cars? If you look at the top of the page, there is a blue header that lists the Forums, the how-to guides, and a category named "More Info" . . . click on the more info and you will see Reatta Vendors among other choices. At the top is Jim Finn who provides used parts from Reatta's and he is very knowledgeable about differences that are in the 1991 model versus earlier years. He is certainly one vendor who might be able to address your questions, not to say that others are not. Edited December 4, 2019 by Nittany Typo Link to comment Share on other sites More sharing options...
Heffy Posted December 4, 2019 Topic Author Share Posted December 4, 2019 I am looking for the upper main ICM harness. Appreciate the knowledge of looking for 91 thru 95 Riviera as possible sources. I wonder if there are any other GM models with a similar harness. Also, where can I find the GM part number? Thank you all for getting back to me! Link to comment Share on other sites More sharing options...
Ronnie Posted December 4, 2019 Share Posted December 4, 2019 Are you looking for part #28? If so this might help... 1 Link to comment Share on other sites More sharing options...
2seater Posted December 5, 2019 Share Posted December 5, 2019 Most excellent post Ronnie. Having a part number allows a search over a series of years and models, all good things. 1 Link to comment Share on other sites More sharing options...
Festess Posted December 14, 2019 Share Posted December 14, 2019 On 12/3/2019 at 10:39 AM, Heffy said: Hello I must replace the main ignition module wiring harness on my 91 Reatta. I can not find a part number or a source of the part. I would appreciate some information if anyone has an idea. Thanks Link to comment Share on other sites More sharing options...
Festess Posted December 14, 2019 Share Posted December 14, 2019 AUTO ZONE TOLD ME ME THE HAD ONE FOR MY 89 REETTA FOR A 120.OO DOLLARS IF I NEEDED ONE. SOUTH BEND INDIANA . Link to comment Share on other sites More sharing options...
Heffy Posted December 14, 2019 Topic Author Share Posted December 14, 2019 I believe, from the diagram it is harness 82 that runs on the top of the engine. One part number may be 12107426 Thank you so far for the help Link to comment Share on other sites More sharing options...
2seater Posted December 14, 2019 Share Posted December 14, 2019 If you are looking for a harness that runs to or through the firewall, I am with Nittany and contact Jim Finn Link to comment Share on other sites More sharing options...
Heffy Posted December 14, 2019 Topic Author Share Posted December 14, 2019 (edited) I believe, from the diagram it is harness 82 that runs on the top of the engine. One part number may be 12107426 Thank you so far for the help Festus Thank you for your assistance. However, I believe there is a difference between the 89 set up and a 91. However, if the above GM number match's it may work I will contact them. THX Edited December 14, 2019 by Heffy add comment Link to comment Share on other sites More sharing options...
Heffy Posted December 14, 2019 Topic Author Share Posted December 14, 2019 Festus Please send address for the auto zone. It will help to contact them THX! Link to comment Share on other sites More sharing options...
Ronnie Posted December 15, 2019 Share Posted December 15, 2019 6 hours ago, Heffy said: I believe, from the diagram it is harness 82 that runs on the top of the engine. One part number may be 12107426 From this it sounds like you want the harness on top of the engine. I'm starting to get confused. Originally I thought you were wanting the harness that goes to the Ignition Module. Which harness do you need? Link to comment Share on other sites More sharing options...
2seater Posted December 15, 2019 Share Posted December 15, 2019 56 minutes ago, Ronnie said: From this it sounds like you want the harness on top of the engine. I'm starting to get confused. Originally I thought you were wanting the harness that goes to the Ignition Module. Which harness do you need? I am sort of lost also. The ICM and a few sensors connects via a short harness on the pulley end of the engine. It connects to a plug that sticks out of the harness that comes from the firewall and much of that large harness runs to lots of other items on top of the engine, IAC,TPS, MAF, injectors. If that's not true, then the wiring is completely different than a '90 Link to comment Share on other sites More sharing options...
Ronnie Posted December 15, 2019 Share Posted December 15, 2019 Maybe Heffy will clear it up for us. Link to comment Share on other sites More sharing options...
2seater Posted December 15, 2019 Share Posted December 15, 2019 1 hour ago, Ronnie said: Maybe Heffy will clear it up for us. That would be most excellent. I know I desire to be accurate regarding answers so.... With accuracy in mind, I just looked at that '95 S/C engine, the last year of the Series 1, and it sure appears to have the same sub-harness as the '90 and the connector is located behind the power steering pump. Much of the rest of the wiring on the rear was cut off since this is a junkyard engine, but the portion that runs forward of the plenum is intact and does contain connections for the injectors, tps, maf etc.. I am pretty sure there was no disconnect between the firewall and the engine or they would have unsnapped it as was done with other connectors. One thing to note is the '91 does not have EGR so that wiring may or may not be present but was added back on later models. 1 Link to comment Share on other sites More sharing options...
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