Will not start after replacing the engine, could it be the Neutral Safety Switch?

GRANT3588

MEMBER
1990 GMC C1500
5.7L
V8
2WD
AUTOMATIC
200,000 MILES

I have the truck listed above, 1500 two-wheel drive 350 engine. I got it and then put an engine in it, and it will not start. I tried everything tested everything but I can't get spark or fuel I'm getting fuel. It's just not going through the injectors tried replacing the computer. Then I was kind of wondering if it was a neutral safety switch but I don't know where it is, haven't been able to find much information on this truck. Any help is appreciated.

Friday, June 24th, 2022 AT 6:33 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,182 POSTS

Hi,

The first thing to do is check to see if the injector A fuse and ECM ignition fuses are good. Both are located in the fuse block. (See pic 1 below) In addition to checking the fuses, make certain there is power to and from them. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If there is no power to them, go to the firewall and locate the junction block (see pic 2). Each wire from the junction is a fusible link. A fusible link functions as a fuse but looks like a regular wire.

These links are what power the fuses. Check to make sure there is overall power at the junction and then check and confirm each of the wires has power to and from them as well.

Let me know what you find.

Joe

See pics below.

Images (Click to make bigger)