On battery hookup truck cranks no key in?

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RamDiver

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The fault = the starter motor is receiving 12 volts at the solenoid wire

Trace the small wire from the starter (solenoid wire) either by color or physically following it back to the starter relay and determine why is has 12 volts constantly. This line should only have 12 volts when the key switch is in the start position.

The key switch start position should be triggering the start relay to close and supply 12 volts to the small wire (solenoid wire) on the starter.

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lance1586

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The fault = the starter motor is receiving 12 volts at the solenoid wire

Trace the small wire from the starter (solenoid wire) either by color or physically following it back to the starter relay and determine why is has 12 volts constantly. This line should only have 12 volts when the key switch is in the start position.

The key switch start position should be triggering the start relay to close and supply 12 volts to the small wire (solenoid wire) on the starter.

.
 
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lance1586

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I’m tracking you and agree. So, the bro wire I’m holding was plugged into the EGR sore which is right next to the SOL spade this bro wire runs directly from the battery and doesn’t look factory appears added on. If I unhook this hot I get nothing no “auto start” but no start off key. If I plug that bro wire into the Batt terminals top right same no auto steer but no key action. That bro wire is feeding everything but not switchable?
 
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lance1586

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And there are only two wires to the starter and neither appears to be defective or grounding out anywhere?
 
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lance1586

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I know which wire is the ignition but can’t figure out why it’s getting constant power. Well, I do know it’s that brown wire running directly from the battery to the relay. That’s the way it was and don’t know what changed. They did that for a reason?
 
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lance1586

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And there are only two wires to the starter and neither appears to be defective or grounding out anywhere?
Yes only two wires to the starter and both wires appear fine I haven’t unwrapped the entire length and got inside the “bundle” but this was all working before it sat for a year?
 

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There are 2 wires on the starter motor. The large wires should be directly connected to the battery, see the drawing in the earlier post.

The second smaller wire (solenoid wire) on the starter motor should be connected to the starter relay on the fender. If wired correctly, I would expect the small wire on the starter (solenoid wire) should be connected to the SOL terminal on the starter relay on the fender.

The brown wire you're holding in the picture, if it's connected directly to the battery, I'd say it belongs on the BATT terminal on the starter relay.

Now, you just need the ignition wire to energize the starter relay. You should be able to measure 12 volts on the ignition wire when the key switch is in the start position only.

The EGR terminal is not just beside the SOL terminal, as you said, they're bridged together. If you apply 12 volts to the EGR/SOL terminal, that will engage the starter solenoid and the starter will crank the engine.

You're getting closer. Where is the ignition wire from the key switch?
.
 
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lance1586

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So I ditched that block and just put new spades so you could see where they’re running. Moved the suspect bro wore to the batt terminals and it doesn’t auto start but nothing off the key either?
 
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lance1586

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So I ditched that block and just put new spades so you could see where they’re running. Moved the suspect bro wore to the batt terminals and it doesn’t auto start but nothing off the key either?
 

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lance1586

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Low left orange wire is going to I ignition terminal where it was.
 
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lance1586

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I’m not leaving it like this I’ll reuse that block when I finally figure it out.
 

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OK, if you've decided the orange wire is from the ignition key switch, it should have 12 volts when the key is moved to the start position. If you don't have an assistant, pull the orange wire off the starter relay and jamb the positive multimeter test probe into the lug, and negative into a ground somewhere.

Rest the multimeter against the windshield so you can see it from behind the wheel, set it to DC volts, and start jiggling the key switch around while in the start position. Don't forget to step on the brake pedal while starting.

You may have to physically trace the path of that orange wire back to the ignition key cylinder.


starter relay w starter motor.jpg


This drawing shows a schematic for the starter relay.

starter relay drawing.jpg

When the ignition switch is moved to the start position, the ST terminal receives 12 volts which then is applied to the relay coil, energizing the relay and closing the switch. This in turn sends the 12 volts from the battery connection to the SOL terminal of the starter relay which is connected to the starter solenoid (small wire on the starter). With 12 volts on the starter solenoid, the starter motor is engaged and cranks the engine.

If the orange wire is the ignition wire, it should have 12 volts when the key is in the start position. Inline with that ignition wire, there could be a neutral safety switch that has failed open or there could be a safety interlock such as the requirement to step on the brake before starting.

So, when you're testing for the 12 volts on the ignition wire during key switch start, be sure to step on the brake while you're looking for the 12 volts.

.
 
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lance1586

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The ignition wire is lower left I got home late and haven’t had time to check to see if that wire has 12 volts to it. When I hook the bro wire with white stripe to the Batt terminal (either one) I get nothing no “auto start” but nothing on the key either. I can’t for the life of me understand how this was working as it was wired before? I didn’t start monkeying around with the relay wiring until
 

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lance1586

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I did remove the neutral safety switch wire and hooked a wire to its post on the relay and grounded it and no change. I’ll check voltage to the ignition wire in the am. Btw it’s a manual so no need to step on the brake.
 
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lance1586

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With key on (not to start I’m by myself) no power to ignition or any other post except the batt post which is being fed directly from the battery.
 
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lance1586

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Checked this am and no power to the ignition wire with key on. Didn’t check when I crank position but I’d say no or it would crank;)
 

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OK, full stop, and let's step back and verify something that's critical.

Please post the make and model number of the start relay mounted on the fender. We need to confirm that we have this relay wired correctly.

And would it be possible to trace the small wire on the starter motor back to the relay?

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lance1586

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Thought I had posted but I did check KO ignition wire no power. I didn’t check it when turned to crank position I’ll just have to stab my 12v probe in there and watch it from the cab.
 
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lance1586

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Sorry for double post this forum isn’t optimal on my mobile device so apologize for the duplicate pics and posts. I will get the specs on that relay tomorrow am I had the same thought it seems like the Ignition post should be stand alone and this one is tied into the EGR I should’ve kept the only one but tossed it bc the new one plugged in as the old one did and I thought I was good to go. I do remember at the parts store they had brought in 3 different relays first one was a ford style one the other two appeared identical and I chose the less expensive of the two.
 
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