Truck wont start occasionally

I have a 2008 Lincoln Mark LT. A few months back I hopped in and it wouldn’t start. Just heard one click. Got out the battery charger and it started right up. Then it happened several more times. I made sure no lights were left on and all the doors were shut. The battery is only a year old, but I had the battery tested several times and each one said the battery is fine. Two different mechanics couldn’t find the problem. I’m tire of getting stranded and having to wait on AAA. Any thoughts?

I am assuming the starter was also tested. That would be a no-brainer.

I went through this on an older Ford truck as well. The problem was extremely intermittent and luckily it is a manual so I could roll start it. I replaced the firewall mounted solenoid, ignition switch, and ran an additional ground over time and that seems to have fixed it. This is all stuff you can do in your spare time for not much money.

1 Like

Yes starter was tested. I was wondering if it might be the ignition switch. I’ll check those out.


It got to the point where this was so intermittent that it NEVER did it at the shop and it was cheaper and easier for me to throw a few random parts at it. All these were definitely under $100.

Next time it happens, wiggle the shifter and or shift into neutral and try to start it. If it starts right up, replace the neutral safety switch.

Also check the battery cable connections on each end to make sure there is no movement.

Might also swap the starter relay in the engine bay mounted fuse box with an identical one for another component to see if that fixes it.


Was the battery actually low, then? This isn’t clear from the discussion so far.

My 1997 4.6L Ford doesn’t really have a starter relay. I might have swapped some type of multifunction relay that might play a part in this during my testing but the main “relay” is the solenoid on the firewall for me.

The truck in question here is a newer generation and likely uses the 5.4L so it might be completely different.

No, the battery was never low. My charger has a “start” setting which provides more power for jumping.

Yes it is a 5.4L

Starting this truck is done by the ECU. The key is turned to send a signal to the ECU which takes over by energizing a relay in the fuse box to crank the starter. It keeps it energized until it starts… within a time limit preventing the starter from burning up.

That’s how modern cars are started irrespective of the engine type. My '07 4.6 liter 3 valve V8 started the same way as does my Chevy 5.3 V8. Both still have starter solenoids but they are triggered by a relay driven by the ECU.

Makes compression tests easy… jump the relay to spin the engine instead of diving under to attach the jumper switch cables to the starter.

I have a 2015 Mitsubishi Mirage that definitely seems like it requires a command from the ECU to start. It will not crank if already started and you can tell there is a tiny delay before cranking starts. Also, this is a manual. If I accidentally stall it, there is a several second delay before it will crank again, like the ECU has to be sure the engine is actually not running.

I figured the 1997 was just a contact of sorts as it seems to crank as long as you hold the key, etc. It will even crank with the engine running so doesn’t have that safety interlock to protect the starter/flywheel. Maybe the ECU still sends the signal but it is certainly a lot more simplistic on the 1997.

My thought is that it will require troubleshooting. Since it’s an intermittent problem and it resolves itself before your mechanics can look at it you’ll have to troubleshoot it yourself at the time it fails.

Check the voltage from battery positive TERMINAL to negative TERMINAL at the time of failure. Should be 12 plus volts.

Check the voltage from the positive battery CABLE to to the negative TERMINAL at the time of failure. Should be 12 plus volts.

Check the voltage from both sides of the starter relay to the negative battery TERMINAL at the time of failure. Should be 12 plus volts.

Check the voltage from the big connection (NOT THE WIRE) on the starter to the battery negative TERMINAL at the time of failure. Should be 12 plus volts.

Finally, check the voltage from the negative battery TERMINAL to the engine block at the time of failure. Should be zero volts.

And when I say at the time of failure, I mean when you turn the key and it clicks, not right before, not right after. Failure is when it is clicking and not cranking.

The contacts are worn in the starter solenoid, replace the starter assembly.

Maybe, but the one click could be something other than the starter solenoid. Unless I could hear/feel from right next to and touching the starter solenoid at that moment, I would not assume the problem is there.

If there is movement at the solenoid, a problem with the contacts in the solenoid is more likely. (The battery and its connections are OK, right?)

An auto electric shop can replace the contacts and do other repairs to a starter motor that you bring in to them. I would trust them as much or more than a new or rebuilt starter out of a box.

I’m leaning toward Nevada’s advice also, problematic starter motor. “Clicking” is common symptom for that. Suggest however to ask your shop to double-check you have clean, tight connections at battery, and that voltage(s) at starter motor meet minimum spec when key is in “start”. Some starter motors have two terminals; that type contains starter solenoid ass’y inside the starter motor. Some types (mostly pertains to certain Fords, my Ford truck for example) have one terminal; in that version the starter solenoid ass’y is a separate part, often bolted to the engine compartment firewall. In either case, starter motor should crank engine when its terminal(s) are powered with at least 10.5 volts. Measure between starter motor terminal(s) and starter case. If voltage(s) ok, and engine isn’t locked up for some reason, replacing starter motor is the next step.

Possible, but the voltage test above will fail if there’s an ignition switch problem.

Your car is getting old. Some parts corrode and maybe you should change your negative battery cable. The negative cable isn’t well made when compared to the positive one. If any part of the cable insulation looks cracked, you will have found at least one potential problem. I would change it without checking it and see what happens. Ford used to like to run the cable to a point on the fender or frame and continue it to the engine block.

I ran an extra ground from the battery to the starter on my truck. The cable was like $20 or less so it seemed like a super easy fix. My truck is also getting pretty rusty and crusty so I figured this was an easier fix than trying to track down the exact connection giving me trouble or paying someone else to do it.

The frame has to be grounded to the battery also. You have done half the job. If you run one wire to the body/frame from the negative terminal you will be at 100%. Or run it from the starter to the frame to accomplish the same thing. I know it doesn’t sound like it helps but it does.

Makes sense. Starter motors draw more current than any other device in the car. Easily 100 Amps during initial stages of cranking. If there’s anyplace in the circuit with slightly high resistance, even as little as 1/10 ohms, that will drop the voltage 10 volts, leaving only 2 volts for the starter motor. Ohm meters generally not accurate at measuring 1/10 ohm, so hard for diy’er to figure out where the resistance problem is occurring. Adding the extra wire can then make a lot of sense $$ and time-wise, b/c the diy’er ,doesn’t have to figure out where the resistance problem is located.

The solution to that measurement problem is to monitor the battery voltage while cranking the engine. A 5 volt drop pulls the voltage too low to start.

1 Like

I think it might be the starter. It started yesterday after sitting two days. Went back out 20 minutes later to try it and it wouldn’t start by key or by remote start. Put the charger on it today. Set charger to the starter option and it didn’t start.