I need some guidance with OBS wiring

[SlowAndHighTBI]

I'm waist deep in my swap, and I have a few questions about my TBI engine harness.

I'm swapping a 2003 DBC LQ4 into my 89 k1500 5 speed. So far I have deleted A/C, evap, and cruise. From what I understand, I will not need The TBI ECM for anything. However, there are a bunch of body power wires, hvac wires and gauge wires spliced into the TBI engine harness. Do I just need to seperate these wires, and hack all of the actual engine wiring from the harness? I'm going to try to tidy up the engine bay the best I can, without removing necessary wiring.

As always, your input is appreciated.

[SlowAndHighTBI]

Just to clarify, The LQ4 harness is stand alone, and it's already done.

[bobbylog]

You can remove de TBI PCM and cut all TBI engine harness except "oil pressure sender and coolant sender" You can keep the pink or red distributor wire for 12v ignition on and cranking.All the gauge wire can be connected inside the cab in the glove box try to find your electrical diagram.

[Mickeymotormount]

I also ended up using the TBI injector + wires to supply keyed power to the PCM. Since the old PCM controls the ground to the injectors, they are always hot with the key on. Seemed like a good place to get key on 12 volts. The other keyed source for the PCM came from the old HEI ignition power wire. Works like a champ.

[kewljay223]

i didnt check the power distribution diagram before posting this and since your not having any issues i assume it might be ok, but just thinking out loud here.... since the injectors are small, im guessing they dont draw too much current so the fuse/wire is probably not that big... can it handle the load of supplying everything needed for key on power for the new fuse block??? if it just supplys power to a relay, then disreguard this but just somehting to check into...

[SlowAndHighTBI]

Thanks for the info guys. One last question. Is the single wire that plugs into the top of the tbi alternator for the volt gauge? I'll probably need that too.

[kewljay223]

the real big wire you mean that has a lug on the end and is held in place by a nut?? that goes straight to the battery. thats how the alternator charges your batt and powers the rest of the car. your volt meter im pretty sure is just connected to a ign switch positve. check your diagrams out which will tell you

just checked a few diagrams real quick. couldnt find one in your year but they seem to be the same. are you talking about the brown wire? if so then yes you are correct. that does go to your volt gauge. i was wrong about the ign positive. my apologies. heres a diagram from a 91 k1500. should answer your quesion

[SlowAndHighTBI]

Yeah, I was talking about the brown wire, I should have mentioned that. Thanks for the help, Kewljay.

[Mickeymotormount]

I believe that is for the battery light. At least that's what it's for on my 93. Not sure what your guage cluster has for lights.

[kewljay223]

I believe that is for the battery light. At least that's what it's for on my 93. Not sure what your guage cluster has for lights.

yup. good call mickey. i was right the first time. always go with your gut!!! i just looked at my gauge cluster diagram again and there is a battery indicator light and a volt gauge. the gauge is like i said, hooked to ignition power. the brown wire you are referring to goes to the light bulb in the dash like mikey pointed out. idk how i missed that. probably because ive worked 14hr shifts the past few days...lol

but to be honest, idk what that lamp indicates. only thing i cant think is low battery. i just dont get how it works tho. as you can see in the diagram the other side of the light goes to switched positive. what does the brown hook to inside the alternator? i assume it has to be a ground of some sort...? but when does the ground actually make a connection to power the lamp? when the alt fails? anybody know how this works?