96 vortec 5.7 won't start

IdahoCallaway · February 26, 2015

I have a 96 gmc k1500 with a 5.7 and a 5 speed manual, the truck won't start!! It first started stalling once in a while and then it started right back up after it stalled, then it started doing it more and more, now its completely dead, the motor with turn, I believe its something Electrical because when I put the key in and turn the key to the ON position none of the gauges light up, no read on the oil pressure, no voltage is read, no fuel level is read... no normal lights come on in the gauges, the only that comes on is the radio..... Fuel pump is new and so is fuel filter, New Spark Plugs, Battery is good, alternator is good and so is the ICM(ignition control module), no fuses are blown either.... When i use my electrial tester on the fuses there is no power getting to 3 fuses all others light right up, the 3 fuses are IGN-I, ECM-I, and ENG-I..... randomly all the gauges will work and i can hear the fuel pump come on and it will run just fine, no problems, but then it will die 10 or seconds after that and won't work for multiple days..... I'm thinking its a bad computer, is there anyway i can test it?

00Silverado4x4 · February 26, 2015

First thing I'd check is all electrical connections, especially battery cables to and from battery. You may have one loose or corroded.

IdahoCallaway · February 26, 2015

First thing I'd check is all electrical connections, especially battery cables to and from battery. You may have one loose or corroded.

I tried that, took positive and negative cables off and inspected them closely and they look good, no rubbing at all on the them....thinking maybe just bad fuses, might try and swap them out and see what happens

00Silverado4x4 · February 26, 2015

What about the other end of the battery cables, block ground and starter? Were they good too?

IdahoCallaway · February 26, 2015

Ya no problems at all, little grim on them but I wipe them all clean, still didn't affect anything.... One thing that did happen the other day is when j was messin with the crankshaft pos sensor, everything came on for a couple seconds while it was unplugged once... Idk if it was just random or if it is the cps... When I run a tester to the plug in I get no power to it

00Silverado4x4 · February 26, 2015

If no power to TPS then I'd start with fixing that and then move on to the no start. I have a feeling, if you solve the TPS power problem your no start is going to be fixed as well.

1997SierraSLT · February 26, 2015

This may be a stretch, but how about the neutral safety switch located on the steering column.

seansharley · February 26, 2015

Sounds like the ignition switch

los33 · February 26, 2015

I work on many trucks like this but mainly bagged.

Things to check:

1. Is the battery good?

2. Are any of the battery cables fried or fuses fried to ignition and battery?

3. Ignition switch has gone out

4. Is alternator working or connected right? Battery may have some charge, but not much.

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IdahoCallaway · February 27, 2015

Sounds like the ignition switch

Its not the ignition switch because I bought a new one and still nothing.

IdahoCallaway · February 27, 2015

I work on many trucks like this but mainly bagged.

Things to check:

1. Is the battery good?

2. Are any of the battery cables fried or fuses fried to ignition and battery?

3. Ignition switch has gone out

4. Is alternator working or connected right? Battery may have some charge, but not much.

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Yes, battery is good, checked all battery cables alright and they are all good and no fuses are blown, ignition switch is fine because i put new one in and nothing changed. And yes the alternator passed all tests at Autozone..... The truck turns over normal but just missing the ignition contact

This may be a stretch, but how about the neutral safety switch located on the steering column.

Is this the little white switch on top of the steering column or is it the black box on the bottom?

seansharley · February 27, 2015

Its not the ignition switch because I bought a new one and still nothing.

No gauges, lights when you cycle the key is usually ignition related, especially if its intermittent with cycling the key. You may have a bad connection, wire, or ignition control module.

los33 · February 27, 2015

Is this the little white switch on top of the steering column or is it the black box on the bottom?

Usually the black box on the left of the steering column under the truck

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IdahoCallaway · February 27, 2015

Usually the black box on the left of the steering column under the truck

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Okay I will look at it tomorrow and put the tester on it and see if i get anything, i believe its somewhere between the ignition switch and the fuse box

No gauges, lights when you cycle the key is usually ignition related, especially if its intermittent with cycling the key. You may have a bad connection, wire, or ignition control module.

Ya im with ya im 100% thinking its ignition related... the icm passed the test 5 times at autozone, and the new ignition switch didn't change anything so i returned it... i was thinking it was the crankshaft pos sensor but i wouldn't think that would affect gauges and what not...

seansharley · February 27, 2015

I would try one from GM, what are they, 39-40$? Its very common for what you're describing, or a cracked wire, bad connector. Maybe start by wiggling all connections with someone monitoring the lights/gauges in the dash. There is a fuel pump relay, oil pressure sensor also, but they wouldn't effect the lights, and gauges, i don't believe anyway.