Starter trigger wire question [SOLVED]

[THEREAL5double0]

Hey everyone, new to the forum here.
I searched for my question and did not find it, so apologies if this needs to be moved to a different section.

2012 PPV Tahoe (5.3L LY5/6L80)

I’m getting no signal on the starter trigger wire when attempting to start. Starter relay is passing signal to the 40amp fuse. Fuse is blown.
I’m thinking a short to ground between the fuse and the starter solenoid.

What I need to know is:
1. what color wire goes from the 40amp starter fuse to the starter solenoid?

2. Does it go directly to the starter solenoid or, does it go back to the transmission IMS before it goes to the starter solenoid?

3. What wire colors? (Seems to be purple to the connector at the starter solenoid). Research online has not been helpful so far.

Some background:
I just swapped in a rebuilt LY5 5.3l.
The shop crane load leveler did press against the wiring loom on the cowl during the process, so I’m thinking if that purple wire runs across there, it might have been damaged and is now shorting.

Again, Key start position does activate the relay and passes voltage to the 40 amp fuse. I created a jumper in place of the fuse and it arced so, I’m thinking we have a short between there and the starter solenoid.

Thanks in advance for any assistance.

 

[mikez71]

Purple, direct from fuse to starter. Not sure the routing.

 

[THEREAL5double0]

Thanks. I’ll trace and report my findings. I also ran a test light across the spades where the starter fuse would go and it lit up but didn’t trigger the starter. That tells me the cold side spade is possibly going to ground somewhere. Or, the solenoid is possibly shorted to ground and no good. I’ll disconnect the purple wire from the starter and jump the fuse terminals with the test light and see if it lights up. If it lights up, that will indicate a short to ground. I’ll also do a continuity test end to end on the purple wire and see what the meter tells me.

 

[Fless]

Wiring diagrams on www.charm.li.

 

[THEREAL5double0]

Wiring diagrams on www.charm.li.

Perfect, thanks!
Found it.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

It seems like you are going down the right track with your troubleshooting.

Did you rule out the starter itself, or something within it, being the source of your issue? If you take a test wire, connect it to the battery + terminal, and then touch the starter trigger, at the starter with the other side, does the starter operate?

 

[THEREAL5double0]

Thanks. I replaced the trigger wire and now get a light on my tester when key to start position. Still no response from the starter. I noticed the pigtail showed signs of heat so I am thinking either solenoid or starter motor went bad and blew the fuse/ heated the pigtail. Now that the trigger wire is new from the fuse box output and testing good, I ordered a complete replacement starter and should have it installed by Monday evening at the latest. I’ll update once complete.

 

[THEREAL5double0]

My GM trucks, since pics were requested.
‘08 Z71 crew, ‘12 Tahoe PPV and ‘91 GMC 6.2 diesel Suburban SLX

View attachment 469562

 

[THEREAL5double0]

Update: installed new starter and issue resolved. Thanks everyone.

 

[Joseph Garcia]

Thank you for posting and title tagging your solution to your issue. Our collective knowledge base has been increased.

 

[Fless]

Wonder if the new trigger wire doesn't need to be there now?

 

[THEREAL5double0]

The trigger wire was bad as well.