Dash swap wiring help/info needed

[baggedlongbed]

I have a 98 C1500 RCLB that I'm swapping the dash out on and have run into some issues . The donor parts all came from a 96 Tahoe 4dr . I have the entire dash with harness and what I think is the harness that runs along the firewall . Its obviously a good bit different from the one I'm removing. Does anyone know what that harness is refer to as or have a diagram for it ? I have a air bag module under the drivers seat but the donor harness doesn't seem to have a plug to go to it and there's a few other things that are different. Hopefully someone maybe has done this swap before and can help me out .

 

[east302]

Whenever I’ve done mine, I just swapped my old harness into the donor dash. It’s all just clipped in one way or the other once you take the a/c duct off. Could you not do that?

To (sort of) answer your question, I think GM called it a crossbody harness. There is a sticky on this site for the factory manuals though I’m not sure that a 96 is specifically covered. An alternative would be a subscription to alldatadiy which would have the diagrams for a 96.

 

[baggedlongbed]

My truck was in a flood 9yrs ago so all the factory wiring has to go . Thats why I bought everything from the donor. I figured it'd just swap all over no big deal other than theres obviously more length and a bunch of things that a 4dr Tahoe has that a regular cab work truck doesnt lol . I will check the thread for the manuals and see if I can find anything. I just want to make sure I have everything I need and connect everything cause after I get the dash painted its not coming out again lol.

 

[Bill C]

one of the issues you will find is the wiring from the engine harness that go into the cab below the ac reciever dryer will have substantially different wiring and connectors between years. and if one truck had the c60 system with airbags. and the other had airebags, c68, power windows, etc youll run into a lot of subtle differences. I picked up a 2000 k3500 for the l29 7.4 to swap into my 97 c1500. the differences are enough it is actually going to be simpler for me to just remove all the 97 wiring and use the 00 k3500 wiring. luckily i removed every harness, and sub harness, dash cluster, hvac controls, blend door motors.. literally everything from the 2000, so when im done it will just be a 2000 when a scanner is plugged in, or if troubleshooting any electrical. the over 8600 gvwr heavy duty k3500 doesnt have airbags.

 

[baggedlongbed]

one of the issues you will find is the wiring from the engine harness that go into the cab below the ac reciever dryer will have substantially different wiring and connectors between years. and if one truck had the c60 system with airbags. and the other had airebags, c68, power windows, etc youll run into a lot of subtle differences. I picked up a 2000 k3500 for the l29 7.4 to swap into my 97 c1500. the differences are enough it is actually going to be simpler for me to just remove all the 97 wiring and use the 00 k3500 wiring. luckily i removed every harness, and sub harness, dash cluster, hvac controls, blend door motors.. literally everything from the 2000, so when im done it will just be a 2000 when a scanner is plugged in, or if troubleshooting any electrical. the over 8600 gvwr heavy duty k3500 doesnt have airbags.

I think I have everything . I have the complete dash with attached harness,HVAC box ,inner door panels with power windows and locks, door panels and steering column from the donor Tahoe. Unfortunately I wasn't the one who removed it all so I'm not 100% sure where all the wiring needs to go . I figure it'll all plug in to itself since its all from the same truck . I'm not worried about the airbags cause I plan on eliminating the drivers and the tahoe dash doesn't have the passenger one. My old harness was very simple and has a bunch of grounds on the passenger side that the new one doesn't have. I also have the engine harness from the donor vehicle which I don't know if I'm going to use cause I'm also LS swapping the truck so I might use a stand alone or something. I'll figure that out when I get to that point. I just need to figure out the dash wiring right now

 

[Caman96]

I think I have everything . I have the complete dash with attached harness,HVAC box ,inner door panels with power windows and locks, door panels and steering column from the donor Tahoe. Unfortunately I wasn't the one who removed it all so I'm not 100% sure where all the wiring needs to go . I figure it'll all plug in to itself since its all from the same truck . I'm not worried about the airbags cause I plan on eliminating the drivers and the tahoe dash doesn't have the passenger one. My old harness was very simple and has a bunch of grounds on the passenger side that the new one doesn't have. I also have the engine harness from the donor vehicle which I don't know if I'm going to use cause I'm also LS swapping the truck so I might use a stand alone or something. I'll figure that out when I get to that point. I just need to figure out the dash wiring right now

Wish I could help, but soon you’ll be the expert.

 

[baggedlongbed]

Wish I could help, but soon you’ll be the expert.

You aint kidding lol . This is one major project and the dash is only the start. I still have everything else to replace

 

[Bill C]

I think I have everything . I have the complete dash with attached harness,HVAC box ,inner door panels with power windows and locks, door panels and steering column from the donor Tahoe. Unfortunately I wasn't the one who removed it all so I'm not 100% sure where all the wiring needs to go . I figure it'll all plug in to itself since its all from the same truck . I'm not worried about the airbags cause I plan on eliminating the drivers and the tahoe dash doesn't have the passenger one. My old harness was very simple and has a bunch of grounds on the passenger side that the new one doesn't have. I also have the engine harness from the donor vehicle which I don't know if I'm going to use cause I'm also LS swapping the truck so I might use a stand alone or something. I'll figure that out when I get to that point. I just need to figure out the dash wiring right now

i was initially going to do a holley efi turbo small block in the 97. half way through collecting parts i got a killer deal on the complete 2000 k3500. it forced me to reconsider. both trucks are manual windows single cab c68 hvac system. i started gutting the 97 main harness and was going to make the 7.4 main harness stand alone. but after studying wiring diagrams. it really is a lot less work to just swap the entire harness. in your situation the suburban usually had 4 power locks, windows, a rear lift gate, as well as rear auxillary hvac. its doable, but complicates the swap substantially. i cant stress this enough.. get the FACTORY SERVICE MANUAL wiring diagram book for the swap & donor vehicle. it will save you a lot of time. you can get them from bischko on ebay in cd rom pdf format, they are searchable. you can open both files at the same time. look for common ground points, connectors etc. it just makes it easier to blend the two harnesses together. i used their manual when i did the holley efi swap in my 91 corvette, and everything in the dash works with the exception of the fuel economy and range features. out of the 15 or so efi swaps i have seen on these cars none of them have been able to keep as many dash features as i did. the factory manual made it possible for me. youll spend 58 bucks per vehicle for the manual. but if you plan to keep it youll want both sets of repair manuals for future reference.. trust me on this!

 

[baggedlongbed]

i was initially going to do a holley efi turbo small block in the 97. half way through collecting parts i got a killer deal on the complete 2000 k3500. it forced me to reconsider. both trucks are manual windows single cab c68 hvac system. i started gutting the 97 main harness and was going to make the 7.4 main harness stand alone. but after studying wiring diagrams. it really is a lot less work to just swap the entire harness. in your situation the suburban usually had 4 power locks, windows, a rear lift gate, as well as rear auxillary hvac. its doable, but complicates the swap substantially. i cant stress this enough.. get the FACTORY SERVICE MANUAL wiring diagram book for the swap & donor vehicle. it will save you a lot of time. you can get them from bischko on ebay in cd rom pdf format, they are searchable. you can open both files at the same time. look for common ground points, connectors etc. it just makes it easier to blend the two harnesses together. i used their manual when i did the holley efi swap in my 91 corvette, and everything in the dash works with the exception of the fuel economy and range features. out of the 15 or so efi swaps i have seen on these cars none of them have been able to keep as many dash features as i did. the factory manual made it possible for me. youll spend 58 bucks per vehicle for the manual. but if you plan to keep it youll want both sets of repair manuals for future reference.. trust me on this!

Unfortunately Im not able to reuse any of the original stuff from my truck so Im hoping to just use everything as close to as is as possible from the donor. I will definitely check out those manuals on ebay. I can see the value in having them. Im not really looking to add anything new besides the factory power windows and locks. As long as I have the basic heat and AC functions along with working gauges Im good. I was looking at the wiring last night and kinda think I know how it all goes and was able to google some parts to find out what they are which helped make sense of it a bit more. I did notice the bulkhead connector for I guess the HVAC stuff on the passenger side is different than the original one so it doesnt connect to the engine harness but I know I have the donor engine harness so Im not super worried . If I could figure out what the harness along the firewall behind the dash is called Id just see if I could get another one to match my factory one Id just swap the dash harness out since I have a replacement that matches my factory one. Then the wiring would be more simplified.

 

[Bill C]

youll find that one harness the issue. the different yhears, and cab configuration substantially change it. get both year manuals. do not get the haynes or chiltons. it has to be gm factorry service manual. it will tell you the different configurations. not trying to nitpick you, just saying its not as cut and dry as you think. some of the early year stuff had power and ground leads going to the passenger side firewall connector that later years did not. it literally changes all of the wiring. it looks subtle on the surface, but its not, it changes the cross chassis harness, and a lot of little things. and if one vehicle was c60/c59 and the other was c68 with auxillary you just opened a huge can of worms. trust me on this. get both manuals and study them before you start cutting wires brother. id hate to see you turn the donor harness into scrap by being overzealous.

I did notice the bulkhead connector for I guess the HVAC stuff on the passenger side is different than the original one so it doesnt connect to the engine harness but I know I have the donor engine harness so Im not super worried . If I could figure out what the harness along the firewall behind the dash is called Id just see if I could get another one to match my factory one Id just swap the dash harness out since I have a replacement that matches my factory one. Then the wiring would be more simplified.