2005 TJ Starts Occasionally

[macleanflood]

You're troubleshooting the ASD relay at this point and that system...make sure you've swapped the horn relay with that one to rule it out as being bad.

If you switch the ignition to run and jumper the big lug on the starter to the small one does it start?

Check your fuel pressure!

-Mac

 

[CharlesHS]

Thanks everyone for the responses. I feel pretty stupid. I climbed under the Jeep today and the three-wire connector located directly under the starter, does not go to the starter; the correct single wire connector was above the starter and could not be seen.

So I tested the wire at the starter, and I only get 12v at the starter every 5-10 times I turn the key.

I took the ignition apart and the actuator pin looks fine. When I turn the ignition with a screwdriver, it still only starts every 5-10 tries. I did notice that if the fuel pump doesn't run when the key is turned to the run position, then the starter doesn't crank. If the fuel pump runs when the starter is turned to the run position, then the starter will crank. Is there a way to test the ignition switch?

I swapped multiple relays with the starter relay and one relay allowed the starter to crank every 2-3 times but it still didn't start every time. Another relay didn't allow the starter to crank ever. So I don't know if all my relays are bad and some are worse than others or what is going on. Any ideas?

You can measure Ohms resistance of the internal coil windings of the relay (pins 85&86); the maximum Ohms should be approximately 70.
IF the Ohms across the windings are much more the relay may or may not engage properly.
I would also check the relay pins and socket clips for oxidation which hinders voltage transfer.

 

[bjamesvw]

You can measure Ohms resistance of the internal coil windings of the relay (pins 85&86); the maximum Ohms should be approximately 70.
IF the Ohms across the windings are much more the relay may or may not engage properly.
I would also check the relay pins and socket clips for oxidation which hinders voltage transfer.

I'm reading 70.0 ohms across the coil windings of the relay, but does that mean the relay always works? I guess I could bench test the relay with 12v and see if it works every time.

The relay pins look good. I can't see the socket clips because they are inset into plastic. I did spray the relay plug inset holes with electronics cleaner and that didn't seem to make a difference.

I think I may just buy a new ignition switch and relay and hope that fixes the problem. If I have a spare relay, that's not the worst.

 

[TJ Jim]

Thought you already changed the ignition switch?

 

[bjamesvw]

Thought you already changed the ignition switch?

I thought I changed it about two years ago, but what else could the problem be? The problem is somewhere between the ignition switch and the starter.

If I knew what the pins of the ignition switch did, I could test it, but I can't find those details.

 

[CharlesHS]

I thought I changed it about two years ago, but what else could the problem be? The problem is somewhere between the ignition switch and the starter.

If I knew what the pins of the ignition switch did, I could test it, but I can't find those details.

Since you haven't previously replaced the ignition switch this was your problem all along.
Hope this wiring schematic helps further troubleshooting.

 

[bjamesvw]

Since you haven't previously replaced the ignition switch this was your problem all along.
Hope this wiring schematic helps further troubleshooting.

View attachment 669391

Thanks for the diagram. If I'm reading the wiring diagram correctly, the PK/OR and PK/LG should have 12v in the start position. Am I correct?

Then I can test the ignition switch and know if that's the problem without buying a new one.

I feel like the ignition switch has to be the problem because the fuel pump and starter both work or both don't work. What else would control both the fuel pump and starter at the same time?