Starter wire question

[98tahoe4dr]

Here’s the connector C1 view for a 98 (as is the diagram). Purple is the feed from the fuse (circuit 806) and purple/white (1035) is to the relay. The wiring diagram looks to be showing the wrong color for 1035.

Does the Ignition (40A) fuse pop as soon as you put it in or just when you turn the key?

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The relay grounds at G105 by the crank sensor.

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Only when I turn the key to start. That's why I think it's the starter "trigger" wire causing the fuse to blow. I've got excellent frame, engine block and body grounds.

 

[98tahoe4dr]

Did the fuse blowing start before or after you worked on it?
It's not two purple wires. It's a solid purple. The other is purple, green, blue, any color with white, black , any stripe is a different wire/ circuit.
Use the actual GM wire diagram. Haynes, Chilton others are incomplete or too generic.

Before. That's why I posted a picture of the neutral safety switch connector... there is 2 purples.. one solid one striped.

 

[east302]

Only when I turn the key to start. That's why I think it's the starter "trigger" wire causing the fuse to blow. I've got excellent frame, engine block and body grounds.

Makes sense. Here are a couple of ideas for you…

Ignition A fuse keeps popping on crank

97 k1500 ecsb z71 5.7 60e Had a lot of issues recently with starting. Mainly eating starters for stupid reasons. Finally got a brand new one instead of crappy remans, new power with from battery to starter, new ad244 alternator and charge wire as well. Drove for a month happily after all...

www.gmt400.com

 

[Road Trip]

Does the Ignition (40A) fuse pop as soon as you put it in or just when you turn the key?

Only when I turn the key to start. That's why I think it's the starter "trigger" wire causing the fuse to blow. I've got excellent frame, engine block and body grounds

Did the fuse blowing start before or after you worked on it?

Before.

Hello 98tahoe4dr,

The above Q & A is very good, and really tightens up the problem description, for given the fanout
from this 40A fuse the circuit choices I initially saw in the wiring diagrams were:

* Hot At All Times
* Hot in Accessory only
* Hot in Run and Start
* Hot in Start Only

So that's solid troubleshooting progress. Your problem description allows us to ignore a whole lot of real estate in the
wiring harness. And since you are able to force the error at will, further troubleshooting will be clear & unambiguous.

But as you have mentioned, blowing 40A fuses every single time you want to test the circuit is a potential budget buster.

And I face a similar issue in one of my other hobbies. (One of the things I do for pleasure is repair/optimize old high-power audio amps.)
Of course, after doing invasive surgery on an amp with 36 250W TO-3 output devices, just plugging it in to full line voltage
and flipping the switch really runs the risk of living through a Wile E. Coyote moment. :0)

Therefore, one of the first things I invested in was a large previously-enjoyed Variac (driven by a little old lady on Sundays while working
on the church PA) so that I can test/verify my handiwork by powering up the patient slowly and with great care. (See attached.)

Q: What does this have to do with you?

A: Others have already suggested this, but I wanted to highlight it just in case you missed it. Temporarily substitute a
single headlight in place of the 40A fuse. This will throttle/limit the max amperage drawn by the circuit (even with a dead short somewhere)
to ~5 amps and also giving you a go/no-go visual indication whether or not you have successfully cleared the dead short condition:

Best of all, instead of the fuselike one-time use scenario, the headlight will last hundreds or even thousands of hours while performing
this current-limiter/virtual fuse function, affording the luxury of time to savor the hunt for the dead short:

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In other words, you are going to disconnect the (smaller) purple cranking wire connected to your starter solenoid,
so in theory with this load removed from a healthy circuit you should draw no appreciable amps/power from this 12v
path when you turn the key to the START position.

IF this circuit still has a short, then the headlamp will light up brightly. You will focus on this circuit until you can
crank the key to the START position and the head lamp remains out. IF your starter solenoid is not a dead short
itself, then you should have regained control over this circuit.

Does this make sense? This all works because the current flow in a series circuit is the same across all components.
So instead of testing with max current until the fuse opens, we are now testing the entire circuit with 5 amps worth
of current. (Should be fine, just don't leave the circuit under test left powered up while unattended.)

I'm going to go poke around the 'Hot in Start only' circuit and see if we can dig up some additional info
for your troubleshooting session.

Don't give up. And when you find the root cause of the dead short make sure and take some clear
photos for others to learn from.

Best of luck in tracking this down --

 

[98tahoe4dr]

I believe it to be the trigger wire, i went to a post recommended above. The guy said using a test light on the positive terminal for the battery put it to the relay slot. Well i got a bright light.. telling me it is definitely a bare wire issue. I ran a new wire from the fuse box for the starter trigger wire(purple). I am going to pick up a relay and some fuses I will let y'all know what happens.

 

[98tahoe4dr]

I believe it to be the trigger wire, i went to a post recommended above. The guy said using a test light on the positive terminal for the battery put it to the relay slot. Well i got a bright light.. telling me it is definitely a bare wire issue. I ran a new wire from the fuse box for the starter trigger wire(purple). I am going to pick up a relay and some fuses I will let y'all know what happens.

My repair worked. I had to run a new trigger wire for the starter.

 

[GoToGuy]

It's not a trigger wire. Electricity, its the power wire.
Why did you change the neutral safety switch?
What number slot did use in the relay bypass test ? One goes to ground= test light, lights up. The other runs to starter = starter turns.

 

[98tahoe4dr]

It's not a trigger wire. Electricity, its the power wire.
Why did you change the neutral safety switch?
What number slot did use in the relay bypass test ? One goes to ground= test light, lights up. The other runs to starter = starter turns.

Ok here we go, so when my issue started I got on just answer (I know now that's a waste of time and money) but he had me trace the relay wires. Each wire at all ends and it started with the neutral safety switch. He stated it tells the ignition what gear the vehicle is in.. (the PRND321 worked but it was so dim I just went off clicks) after tracing all these wires the guy ghosted me. I changed the switch, still didn't start. I came here, I searched the forums for a possible answer to my problem. Most of you guys lead me back to a post after reading it 5 times. I read a part where the guy mentioned hooking a test light to the positive and touching the connectors. Well I disconnected the "power" wire to the starter and covered the end with electric tape, making it an open circuit. I touched the spot where the relay tells the starter to come on and it lit up bright which told me the "power" wire was grounding out somewhere because if it wasn't then the light wouldn't come on. So after all the bs I went thru I bought me a roll of wire, some butt connectors, and ring terminals.. ran a wire from the fuse box (purple wire) across the firewall, dropped it down and hooked it to the starter with a ring terminal. All good now, I turned it on and off about 10 times last night to just verify...

 

[98tahoe4dr]

Ok here we go, so when my issue started I got on just answer (I know now that's a waste of time and money) but he had me trace the ignition wires. **Typo my bad

 

[GoToGuy]