Thanks for reading this.

I have a 1998 Ford F150 Standard Cab, 4x4, Manual Transmission, 4.2L V6 engine. Roughly 92k miles on the truck.

My truck started up fine this morning, but after arrive at work I went to go pick up a pack of cigarettes.

The Truck turns on all lights when the key is turned to the "ON" Position, and operates as normal.
When you turn the key to start the engine all I get is a "Click-Thump".



What I have checked & replaced so far:

• I have checked the (new) Battery and it has proper Voltage and remains at 100% and doesn't drop below ~13 Volts when turning the key. So no dead cell
• I have checked the starter relay above the battery and attempted to bypass it with the clutch engaged, no joy.
• I have replaced the starter, and the same issue persist. (Wires all installed correctly)
• I have checked the starter relay fuses in the interior fuse box near the steering column. No blown fuses.

Notes:

• The truck will run if you push start it and dump the clutch. No unusual sounds when running. No current drop, or battery issues when anything puts a heavy load on the battery (lights, etc.)
• Hooked a Jumper Box up to the battery to see if possible dead cell, no fix.
• Had the original starter tested, and it took 3 tries in the testing machine to get it to fail, but it eventually did.
• After replacing the starter with a new starter, the new one failed
• Had a diagnostic done on the Battery, starter, & alternator. The Battery maintains voltage, Alternator functions, and the diagnostic machine came back with a starter failure.
• When I removed the original starter the gear that the solenoid pushes into the fly wheel had a slight chip/wear & tear on two of the teeth, but I have been told this is normal after 100k miles or so.

My suspicions:

• Defective starter from AutoZone
• A faulty anti-theft system not allowing the fuel pump to engage at start
• A false positive for a defective starter from AutoZone, and the real issue lies in the flywheel being stuck.

Please help. I am out of is places to troubleshoot. short of replacing everything from the battery, wires, fuses, starter, & flywheel.

Thank you so much in advanced for any help.

-Sam

 

Nope. Fuel pump isn't controlled by PATS, only the injectors are disabled in a PATS event. If the THEFT light isn't fast-flashing during a starting attempt, PATS is happy.

Well, the flywheel really can't get "stuck" but something connected to it might be. Perhaps the clutch isn't releasing, perhaps one of the accessories on the serpentine belt is jammed. However, if the kick start works correctly, neither of those sound very likely unless it's intermittent. You can remove the serpentine belt an see if cranks or not, that's fairly easy. On the clutch side, if you can easily roll the truck with the transmission in neutral, that would tend to rule that out.

Have you checked the voltage at the main starter power terminal to see if you still have (nearly) full battery voltage at that terminal during cranking? You might have a cable that's dropping voltage under heavy load and the starter is starved for power.

 

I was unable to check it yesterday as it started down pouring and still hasn't stopped. I moved it to a dry shop and will check the voltage at the power terminal. I believe the required voltage for the starter to run is around 10.5-11 Volts. I am going to replace the starter with a new one & check the voltage at the starter power terminal before the swap. I'll also double check the ground while I am in that area.

If I get a bad read, it is most likely a cable issue (I know these can rust out), and i'll have to replace the cable.

I have looked around online for the cable for prices and I can only find a select few. Does anyone have any part recommendations?

Note: It does start right up when I push start/dump the clutch, and continues to run perfectly (for at least 15 miles from the breakdown location to the dry shop). I did hear a new squeak in the Fan belt, but was able to get it to go away with a wire brush/soap.

Did test this after reading this. The truck rolls extremely easy in neutral, and shifts just fine after it has been push started.



Thank you very much for the assistance.

 

Can I run jumper cables from the batter directly to the starter to see if it is a cable issue before I begin trying to diagnose exactly which cable is wrong? Just to see if it is a cable/connection issue?

Thanks for any input.

 

I wouldn't use the jumper cable as it would likely be carrying almost the full current draw of the starter motor if you do have a bad cable or connection unless you have very heavy gauge jumper cables.

Just do a voltage drop test (under load) on the whole positive segment of the circuit and that will tell you where any defect would be should there be one.

Battery negative post to engine block.
Battery positive post to starter relay input
Starter relay input to starter relay output
Starter relay output to starter motor input

 

I just removed the starter and took it up to AutoZone and had them do a test on the starter and it passed their test 5 different times with no failures. So I guess that leaves the cables being bad.

I'll run the test on the cables that you described above and see if I can get a good read under load (attempted start).

They told me that just doing a surface test of the voltage on the batter is not sufficient to determine if the battery has a 100% charge. They said I can bring the battery in for free and have them do a deep cell charge for free. I figure it can't hurt so I am going to disconnect the battery and have them charge it before the test so I can be sure that it is the cables and not the power source.

If you have any additional input as for troubleshooting it would be much appreciated. God bless.

 

These are the steps I took to fix this issue:

1. Removed the old Starter that failed the bench test & Replaced with a New Starter (Problem Persisted)
2. Checked all connections to make sure nothing was missed, or unsecure. Cleaned all connections (Battery terminals, grounds, everything) -- Problem Persisted
3. Removed the New Starter & Took it to be bench tested by AutoZone, and it passed
4. Reinstalled New Starter. -- No Joy. Would Not start
5. I then checked the wiring via the instructions posted above (thank you). I found that I had a bad power connection from the relay to the starter. The connection was extremely corroded so I took a stainless Steel brush to it until it shined.
6. I then reinstalled the power supply & she started right up.

I think I had a combination of problems. Those being: A bad starter & Bad connections. I'm thinking because of the bad connection I may have overworked the original starter causing it to die.

Started right up & then ran her for a few moments around the block. I cut it off & she started right up again.

If this issue rises again I'll revive this topic. Thank you for your help.