Electrical Starter Question

[1990fredi]

I purchased a 1990 K1500 Sierra, test drove it a few times, everything seemed good, got home and sat over the day, later that afternoon I needed to jump it to get it in the driveway. after that I tried to put the charger on it and it was erroring out so I tried to jump it again and every time I hooked any amount of power to the truck the Starter motor just runs, constantly. now for the part I don't understand. the positive line that goes to the starter, makes the starter run, but also the positive line that goes to the alternator and then to the fuse box which should go through the ignition, that also makes the start motor run.

how can that be and what do I need to do to fix it? I thought the ignition might be bad but when I remove the wire out of the ignition, it still runs, so I am going to try to replace the starter but not sure what else to try.

where do I start, it was just fine, then the day I buy the truck, this happens.

 

[Scooterwrench]

I purchased a 1990 K1500 Sierra, test drove it a few times, everything seemed good, got home and sat over the day, later that afternoon I needed to jump it to get it in the driveway. after that I tried to put the charger on it and it was erroring out so I tried to jump it again and every time I hooked any amount of power to the truck the Starter motor just runs, constantly. now for the part I don't understand. the positive line that goes to the starter, makes the starter run, but also the positive line that goes to the alternator and then to the fuse box which should go through the ignition, that also makes the start motor run.

how can that be and what do I need to do to fix it? I thought the ignition might be bad but when I remove the wire out of the ignition, it still runs, so I am going to try to replace the starter but not sure what else to try.

where do I start, it was just fine, then the day I buy the truck, this happens.

Sounds like the starter solenoid is bad. There is a disc in there that connects the battery to the starter motor,I think yours has come loose from the plunger rod and maybe welded to the battery/motor contacts.
New starter should fix it.

 

[1990fredi]

sounds good, I'll try that.

 

[evilunclegrimace]

OR the starter main lug is twisted around and is touching the the solenoid stud that the iginition controls.

 

[Scooterwrench]

OR the starter main lug is twisted around and is touching the the solenoid stud that the iginition controls.

Wouldn't that energize the solenoid winding and pull the drive out and engage the starter to the flywheel?

 

[SEEDSOWER]

I purchased a 1990 K1500 Sierra, test drove it a few times, everything seemed good, got home and sat over the day, later that afternoon I needed to jump it to get it in the driveway. after that I tried to put the charger on it and it was erroring out so I tried to jump it again and every time I hooked any amount of power to the truck the Starter motor just runs, constantly. now for the part I don't understand. the positive line that goes to the starter, makes the starter run, but also the positive line that goes to the alternator and then to the fuse box which should go through the ignition, that also makes the start motor run.

how can that be and what do I need to do to fix it? I thought the ignition might be bad but when I remove the wire out of the ignition, it still runs, so I am going to try to replace the starter but not sure what else to try.

where do I start, it was just fine, then the day I buy the truck, this happens.

THE STARTER RELAY UNDER THE HOOD CAN STICK KEEPING THE STARTER RUNNING. I THINK THE HORN RELAYS ARE THE SAME, SWAMP THEM TO SEE IF THE STICKING CHANGES.

 

[Lipstickonapig]

THE STARTER RELAY UNDER THE HOOD CAN STICK KEEPING THE STARTER RUNNING. I THINK THE HORN RELAYS ARE THE SAME, SWAMP THEM TO SEE IF THE STICKING CHANGES.

I thought 1990s didn't have a starter relay.

I'm having a prob with '92 k1500.

1992 K1500 manual transmission.







New starter installed.







New clutch safety switch.







New battery.







Runs when jumping starter directly.







Original problem: no start, no click, no power to solenoid.

I'm confused on wiring. There is no starter relay for this model.

I Have the big, maybe 2 guage pos wire from bat to large starter terminal. Then I have a 10ga from s terminal also to battery because that's how the old one that function was wired.

Is there a fusible link for ignition switch? The fusible links look good but haven't tested them.

I don't believe I have the two wires that attached to the starter crossed or touching as they're both well insulated.

As soon as I ground the battery, the vehicle wants to start no key in the ignition and in gear.

The newly installed clutch safety switch does not fully depress with the clutch at rest. I need to find a way to shim that closer to the clutch pedal lever to make sure that switch is fully engaged.

I don't understand why the old starter worked with this wiring in the new one doesn't unless I'm short circuiting somewhere.

 

[Lipstickonapig]

Again, no idea why the old starter was wired this way and worked well until didn't. I found a wiring diagram and looks like the 10 gauge wire should be from the s terminal to a fusible link.

 

[Scooterwrench]

I thought 1990s didn't have a starter relay.

I'm having a prob with '92 k1500.

1992 K1500 manual transmission.







New starter installed.







New clutch safety switch.







New battery.







Runs when jumping starter directly.







Original problem: no start, no click, no power to solenoid.

I'm confused on wiring.

Yup!

Then I have a 10ga from s terminal also to battery because that's how the old one that function was wired.

There's where you're confused. The solenoid wire off the ign/clutch switch should be a heavy(10 gauge?)purple wire that is only hot when you turn the ignition switch to start while mashing the clutch.

As soon as I ground the battery, the vehicle wants to start no key in the ignition and in gear.

That's because you have a constant hot wire going to the solenoid S terminal. Find that purple wire and hook it to the solenoid S terminal

 

[Lipstickonapig]

This figure was in the same manual. So confusing.