At work, need help. No start, 1 click when turn key on

[Lang]

I can jump the starter relay (solenoid) and have 12 V going to the single prong when key turned on. A little baffled on what it could be. Replaced relay (solenoid) with Motorcraft one this morning. Could the NEW relay (solenoid) be bad? Or what else should I be looking at?

 

[Vader's Fury]

Sounds like the starter failed. The click you are hearing is the solenoid engaging, but the starter motor is not turning.

This could also be caused by a bad cable connection either at the starter, or batteries. I would check them first to make sure they are clean and tight.

 

[lincolnlocker]

Sounds like the starter failed. The click you are hearing is the solenoid engaging, but the starter motor is not turning.

This could also be caused by a bad cable connection either at the starter, or batteries. I would check them first to make sure they are clean and tight.

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[Lang]

Sounds like the starter failed. The click you are hearing is the solenoid engaging, but the starter motor is not turning.



This could also be caused by a bad cable connection either at the starter, or batteries. I would check them first to make sure they are clean and tight.

So the truck will turn over when I jump the terminals, the starter motor is bad? Harness is less than a year old but I'll check that.

 

[jngreen]

So the truck will turn over when I jump the terminals, the starter motor is bad? Harness is less than a year old but I'll check that.

The truck will turn over when you bypass the relay?

 

[Vader's Fury]

If you jump the starter relay and the truck will start, you either have a bad relay, bad ground or there is no power coming from the key switch to energize the starter relay. I would check the small pin on the starter relay and see if it has power when you turn the key to start. If so, you may have a bad ground to the starter relay or just a bad relay. It is rare but I have had parts fail right out of the box before so don't rule it out just because it is a new part.

If you do not have power to the small pin then you have an issue in the wiring going from the switch to the starter relay. I have the same problem with my work truck. I just ran a new wire to a push button switch that I hid out of sight inside the truck and it works to start the truck. Added bonus is if you don't know where the button is, you will have a harder time to start the truck as turning the key does nothing now.

 

[bruce]

If you have 12v at the the exciter wires (the small posts on the solenoid) then the new solenoid is junk out of the box

 

[Lang]

Well have 12V going to the starter solenoid on the starter, sooo new starter?

 

[gottagofast]

You SAID the truck cranks when you bypass the solenoid.... That indicates that the starter is fine.

 

[Lang]

Aight need to look at a schematic tonight, doesn't make sense that key ON I have 12V across the relay in the fender well but won't start unless I jump it.

 

[gottagofast]

Yes it does... The starter is the ground path... If the solenoid was closed (ie key turned to start) you would not have voltage across it because both sides would be 12v pos.

 

[bruce]

One side of the solenoid should have 12v constantly, when you turn the key you should then have it on the other side. With the key in the cranking position and the leads on both sides of the solenoid it should read 0vdc. The leads of a dmm measure potential difference so when 12 is on both sides it should measure 0.