NBS cluster with LS swap?

[AK49BWL]

definitely don't use the NBS box, that thing is impossible to customize. At least the OBS box, you can add your own terminals and wires into for more fuses and relays. Or do like I did and get yourself a GEP 96-position box for MetriPack 280 terminals and have full customizability + waterproofing with ISO280 relays and the same MicroFuses the 95+ OBS trucks already use.

 

[slow_c1500]

Ok, I just got a few more small questions.

Do I use the LS alternator and the corresponding plug from the LS harness? Or do i use the OBS alternator (with an aftermarket bracket) and splice in the alternator plug from the OBS harness into the LS harness?

If I am reusing the trans from the OBS, do I use the trans-related plugs from the OBS harness and splice them into the LS harness? And if I used the trans that came with the LS, would I just leave the trans-related plugs as is?

 

[AK49BWL]

I'm only guessing based on your sig that you're swapping a 96... Cuz if so, the alternators are the same, using the same plug and mounting. Transmission wiring pin-out should be the same too, given that the swapped in harness was using the same type of transmission. Say, if you were going from a 4L60E truck to a 4L80E harness, you'd have to use the 60E's wiring harness and splice connections, but the later 4L60E should plug right in to your existing 60E harness. And vice versa.

Things get a lot more convoluted if you're swapping the truck in your avatar (88-89).... I don't think it's been mentioned in this thread what you currently have that you're swapping the LS into. I kind of get stuck in this assumption that I'm working with a 96+ truck sometimes lol.

 

[slow_c1500]

I'm only guessing based on your sig that you're swapping a 96... Cuz if so, the alternators are the same, using the same plug and mounting. Transmission wiring pin-out should be the same too, given that the swapped in harness was using the same type of transmission. Say, if you were going from a 4L60E truck to a 4L80E harness, you'd have to use the 60E's wiring harness and splice connections, but the later 4L60E should plug right in to your existing 60E harness. And vice versa.

Things get a lot more convoluted if you're swapping the truck in your avatar (88-89).... I don't think it's been mentioned in this thread what you currently have that you're swapping the LS into. I kind of get stuck in this assumption that I'm working with a 96+ truck sometimes lol.

your right, trucks a 96 but I swapped the front end and mirrors from an 89. So on the LS harness, I can leave the trans and alternator plugs alone then? I guess that simplifies the process even more, less stuff I gotta tie in from the OBS harness

 

[AK49BWL]

Very nice, yeah mine's a 97 with 88 headlights as well, but you look at the interior and you'd think it's a 94 lol.

But yes, your trans and alt plugs can stay.

 

[slow_c1500]

After looking at some other LS swaps, it looks like, if you want to keep AC, you would need the bracket that puts the AC compressor where the alternator was, and then a bracket to move the alternator the left side. So it may be necessary to extend the alternator wires since they have to reach further? But to my understanding the plug itself is fine, and either alternator works?

 

[AK49BWL]

Yes either alternator works fine. They're virtually identical, but if you happen to get one out of a Suburban, you might get a higher-output alt. But it's still the same footprint and connectors. I can't say much about moving the A/C stuff.

 

[slow_c1500]

Ok, after getting some answers here and looking at the pinouts Ive gotten most of my questions answered besides one.

If i want EVAP to still work, do I need to keep the fuel level and fuel pressure sensors from the LS harness, and somehow integrate them into the OBS tank? Or is only the EVAP purge solenoid necessary, and i can just run a line from the OBS canister to the LS solenoid?

I looked at the pinouts and the EVAP purge solenoid is the only EVAP-related connection that is common between the 2 harnesses. There is one additional EVAP connection for each harness that are different colors and numbers. The LS has EVAP canister vent valve control, and the OBS has EVAP canister purge diagnostic vacuum switch signal. I am guessing those 2 serve different purposes and can't be mated together.

 

[slow_c1500]

Again sorry for the rapid fire of questions but do I need to change any wiring/pins with the OBD2 connector?

 

[AK49BWL]

Shouldn't need to. That connector's pin-out pretty much stayed the same all the way up to even current years... They just added more to it. But for just an LS swap you shouldn't have to worry about it.