Won't start after wired up

[468Blazer]

Heres what I have. 96 gmc 1500 that had 5.0/auto. swapped in 03 5.3/auto.
With nelson wiring/pcm hooked up get nothing with the key. If I put power to starter solenoid it will crank but won't start. It is getting fuel because I smell plenty.

Park/neutral safety switch wire isn't hooked up currently. Also the dash isn't showing any position for P R N D 3 2 1.

If I hook the red wire from nelson fuel pump relay wiring to gray wire on fuel pump it still wouldn't start. Fuel pump kicks on whether the red wire is hooked up or not.

Purple wire in nelson harness goes to solenoid. Do we keep the wire to the small terminal on solenoid along with this wire?

Any help would be appreciated.

[RedHeartbeat]

use the purple wire that was on the original harness to fire the solenoid. Make sure your pink wires are hot with key on and red wire is hot always. Double check your grounds for continuity, you may need a ground from the engine to the chassis if your battery isn't grounded to the engine block. Grounds from the Nelson harness should be grounded to the engine block.

[LSXmyford]

He has a ground wire directly from the battery to the cylinder head.



Your saying the red wire off the fuel pump relay, should be hot, connected directly to battery?


Should there be a ground to the solenoid? He has one hot wire, then he connected the purple wire from the nelson harness to the solenoid, there was a wire on the small terminal already, should he remove that?


And your saying the neutral safety switch only needs to see 12v?

Your saying dont use the nelson solenoid wire, use the OE one?


Sorry bout the rambling questions, I was there with him and my solution was kerosene.



thanks

[RedHeartbeat]

I can't remember the wiring of the nelson harness right off the top of my head but the red wires going to the PCM should have 12v all the time, the pink wires going to the pcm should be switched 12v. The red wire on the fuel pump relay probably should be 12v always, also. Didn't they send a wiring schematic or instructions with the harness?

[farmtruc]

As long as you have ground, power, ignition, and fuel pump working, you should be able to start the engine (whether you hot wire the starter or not)

Let us know, we'll be here,
allen

[LSXmyford]

They sent instructions for the LS1 electric fan install.

The other info was very vague, the answer may have been there but I didnt see it.

[Wtfan18]

i spent hours trying to find out why mine wouldnt crank.... check your starter relay(should be gray i believe and there should be a purple, black, pink and orange i think?) in the fuse box in the engine bay and the little black wire that goes into it is a ground. mine wasnt grounded. as soon as i grounded it it fired... i must have unhooked it somewhere and not re connected it... took me 2 days to figure that out...also as greg said USE THE FACTORY STARTER SOLENOID WIRE unless you already cut it or something... its much easier.

[LSXmyford]

Yeah, we cut it to use as the wire for the nelson harness solenoid wire....


hes gonna reconnect it see if it will fire.


Why would the transmission position not be illuminated in the gauge panel, any thoughts on that?

[LS1GMCTruck]

Ground the battery to the block, Battery to chassis, block to the chassis, power center to the block, etc. Grounds are critical to all LS engine functions. Solid blacks are battery grounds, black w/white tracers are GM chassis grounds. Nuetral safety switch wire to transmission is not needed to run.

[468Blazer]

thanks guys. I'll double check and triple check all my grounds.

I know several other people have had issues with the dash indicator not showing which gear, has anyone came up with a solution? I've tried the old gear selector with no change.