1996 Tahoe no crank

[Old T]

Got a 1996 Tahoe LS 5.7 4wd. Year ago truck started having intermittent starting issues. Finally, while driving it shut off for good. Since then, Ive installed the following:
New starter, ignition switch, starter relay(under hood), crank relay(side of the dash), checked all the fuses. Turn the key and nothing happens. I can only get it to start by either jumping the starter relay or ground the 10AMP crank fuse on the side of the dash and turn the key to run; fire right up. Ive checked the ground wires for corrosion and no issues there. Any other ideas? I appreciate yall's time.

 

[Hoesgottaeat2]

Welcome to the forum.

I suggest you remove the positive battery terminal, and separate it into (2) pieces like the photo below THEN clean all metal surfaces thoroughly with a wire brush, including the battery side post.
When this terminal is compromised with corrosion, it can still power your ignition but without cranking as you describe. My '96 had the same symptoms and this fixed it.
Circle back and let us know how you make out.

 

[YukonGTmaster]

Welcome to the forum.

I suggest you remove the positive battery terminal, and separate it into (2) pieces like the photo below THEN clean all metal surfaces thoroughly with a wire brush, including the battery side post.
When this terminal is compromised with corrosion, it can still power your ignition but without cranking as you describe. My '96 had the same symptoms and this fixed it.
Circle back and let us know how you make out.

View attachment 429679

I hit mine with a mixture of baking soda and water, and a wire brush.

 

[east302]

Here’s the wiring diagram from a 98 which shows the crank fuse. And here’s the diagram from 96 which doesn’t, so you might have to verify the wire colors.


Does it start in neutral? Are your gearshift lights solid (not flickering)?

If you have voltage at the 10A crank fuse, see what you’re getting at the transmission range switch connector (and at B9 on the starter relay) while cranking. It all grounds at G105 near the harmonic balancer.

1998 diagrams:

1996 diagram:

 

[Hoesgottaeat2]

I hit mine with a mixture of baking soda and water, and a wire brush.

Here’s the wiring diagram from a 98 which shows the crank fuse. And here’s the diagram from 96 which doesn’t, so you might have to verify the wire colors.


Does it start in neutral? Are your gearshift lights solid (not flickering)?

If you have voltage at the 10A crank fuse, see what you’re getting at the transmission range switch connector (and at B9 on the starter relay) while cranking. It all grounds at G105 near the harmonic balancer.

1998 diagrams:

View attachment 429684

View attachment 429685
View attachment 429686

1996 diagram:

View attachment 429697

You guys are awesome. Just a helpful bunch of folks. Gotta love this place

 

[Old T]

Welcome to the forum.

I suggest you remove the positive battery terminal, and separate it into (2) pieces like the photo below THEN clean all metal surfaces thoroughly with a wire brush, including the battery side post.
When this terminal is compromised with corrosion, it can still power your ignition but without cranking as you describe. My '96 had the same symptoms and this fixed it.
Circle back and let us know how you make out.

View attachment 429679

Yep that was the first thing I did. I’ve gone a step further and verified the neutral safety works.

 

[Old T]

Got a 1996 Tahoe LS 5.7 4wd. Year ago truck started having intermittent starting issues. Finally, while driving it shut off for good. Since then, Ive installed the following:
New starter, ignition switch, starter relay(under hood), crank relay(side of the dash), checked all the fuses. Turn the key and nothing happens. I can only get it to start by either jumping the starter relay or ground the 10AMP crank fuse on the side of the dash and turn the key to run; fire right up. Ive checked the ground wires for corrosion and no issues there. Any other ideas? I appreciate yall's time.

Here’s the wiring diagram from a 98 which shows the crank fuse. And here’s the diagram from 96 which doesn’t, so you might have to verify the wire colors.


Does it start in neutral? Are your gearshift lights solid (not flickering)?

If you have voltage at the 10A crank fuse, see what you’re getting at the transmission range switch connector (and at B9 on the starter relay) while cranking. It all grounds at G105 near the harmonic balancer.

1998 diagrams:

View attachment 429684

View attachment 429685
View attachment 429686

1996 diagram:

View attachment 429697

Thanks for the diagrams. I’ve checked the wiring. I don’t understand how I can turn the key to run and ground the 10 amp door panel crank fuse and the truck start.

Here’s the wiring diagram from a 98 which shows the crank fuse. And here’s the diagram from 96 which doesn’t, so you might have to verify the wire colors.


Does it start in neutral? Are your gearshift lights solid (not flickering)?

If you have voltage at the 10A crank fuse, see what you’re getting at the transmission range switch connector (and at B9 on the starter relay) while cranking. It all grounds at G105 near the harmonic balancer.

1998 diagrams:

View attachment 429684

View attachment 429685
View attachment 429686

1996 diagram:

View attachment 429697

I’ve found if I turn the key to run and ground the crank fuse it will start.

 

[Old T]

Found the problem folks. After grounding the link between the neutral safety switch and relay B9, that led me to trace the ground wire down to the stud behind the crank sensor. That wire was bad loose.

 

[Old T]

Thank you all for your time helping me get to the bottom of this.

 

[exp500]

Good Job!
Please Edit your title line, add "SOLVED" as this helps find solutions for others. Thanks.

 

[east302]

Good deal, glad you got it sorted out. That grounding of the crank fuse kind of threw me as well.

 

[waveryd]

Glad you got it figured out. As stated above definitely clean and keep an eye on that positive battery cable terminal. I drove a '96 Suburban for over 20 years and 600k miles and had to deal with that cable a lot. In hindsight I should have just converted to top post and been done with it.

 

[Hoesgottaeat2]

...I drove a '96 Suburban for over 20 years and 600k miles...

This is absolutely amazing

...I should have just converted to top post and been done with it.

Wise words. I did eventually do that myself, top post...never an issue related to that afterwards.