no crank, no start (jump the solenoid wire, starts and runs fine)

[Tim Waldo]

So, 2000 RAM, 5 speed. 

I have bypassed the signal wire and jumped to 12v and engine starts, I have checked all fuses and relays (to best of my knowledge), I also jumpered the clutch safety switch which did nothing.... Wait to start light still works as expected, what would keep the 12v signal from making it to the starter? I know I can just put a push button in to bypass but I want to make sure this isn't a bigger picture issue.  This literally popped up outa no where, stopped at a store, and when I got back in it wouldn't crank, I had to roll start it, luckily was on a slight slope. Thanks in advance.

 

Tim

[Tractorman]

The photos below show the wiring circuit for the starter operation. 

 

You can quickly narrow down the problem by removing the starter relay and using a jumper wire to join terminal #30 to terminal #87 in the relay base.  Use the wiring diagram on the relay to identify terminal #30 and #87.  If the starter cranks, then you know:

 

Circuit A - There is current flowing from the driver side battery, through the 30 amp fuse in the PDC, through your temporary jumper wire, and onto the starter. 

 

Circuit B - You would need to check for current flow through the circuit that would begin at the ignition switch, an then pass through the clutch safety switch, the coil portion of the starter relay, connector C130, splice S128, connector C126, splice S168, and finally splice S109 that ends up at the negative terminal of the driver side battery. 

 

If the starter doesn't crank, then you know Circuit B is good and you will need to check Circuit A.

 

- John

 

 

Edited March 31 by Tractorman

[Tim Waldo]

So it is going to take more diagnostics on circuit B, there was no voltage through A at all.... I put in a push button to get by for now (I actually wanted a push button as an additional layer of security)  I am pretty sure the ignition switch just bit the bullet.  So by chance do you know where the bypass is for the clutch bypass is? Always a good to know.

 

THANK YOU for the schematic.

 

Tim

 

[Tractorman]

1 hour ago, Tim Waldo said:

So it is going to take more diagnostics on circuit B, there was no voltage through A at all....

 

If there is no voltage present on circuit A, then the problem is in circuit A

 

How did you arrive at "there was no voltage through A at all."?

 

In circuit A, Fuse #9 (30 amp) in the PDC is directly wired from the positive post of the driver side battery.  Are you saying there is no voltage there.  Terminal #30 on the starter relay in the PDC is wired directly from Fuse #9.  Are you saying there is no voltage there as well?

 

- John