Hey guys,

Had a starting problem this eve that I would like any of your thoughts on finding a cause and hoping to effect repairs which may prevent it from returning. So my truck with a 5.4L Triton has been working fine since I replaced the starter with a Ford reman back in the Fall (it was going downhill for awhile and hitting it with a hammer worked a few times until it didn't, requiring me to finally replace the original starter). Tonight I tried to start the vehicle and each time I turned the ignition key, I would just hear a one-time clunking noise from under the hood and the truck wouldn't start. Lights would all come on, not dim. The starter would not even make a ticking noise so I didn't think it was battery. I checked the battery voltage and it read 10V only, though, While cranking the engine, the voltmeter also read 10V only. I then tried to jump it and with the other vehicle connected to my truck and running, the meter again only read 10V. Moved the gear selector into neutral and tried starting. Same result. Back in Park, same result. I decided to check the clunking noise under the hood while cranking, and followed it to behind a curved plastic cover on the firewall. There I saw what appeared to be a junction connection? or a relay? for the positive cable. It's a round component that has two threaded shafts coming out of it and they are situated side by side. It is where the positive cables are attached and the component is screwed to the firewall. While someone turned the ignition key, I put a finger on this component's housing and felt the clunk coming from it. I wiggled all the wires going to it but did not yet try to start the engine again. Fearing it could be the starter issue all over again, I got under the truck and hit the starter with a hammer several times. I then turned the key and it started right up! Checked the voltage at the battery and it was now reading about 14.5V! (normal). Turned off the truck and the battery voltage now read about 14V (normal). Restarted the truck a few more times with no starting issues. The only thing it did after, and I never paid attention to whether this was normal from before, was after starting the engine, it would idle at about 1100 rpm for about 8-10 seconds, then the rpm's would drop to about 750. This would happen each subsequent time I would re-start the engine.

So if you guys could please tell me what you think happened here and whether you feel the problem could return (and what it was exactly). Many thanks. I feel like we're on borrowed time.

 

Hey guys,

Still having no problems starting my truck but, of course, still trying to figure out what this could've happened that one time of no start. Any ideas anyone?

 

There is a lot of typing to describe all the things that can cause an issue.
Unless you want to be proactive or wait for another cranking failure, consider the age of the battery, the start relay, the starter, battery cables conditions and connections etc., let it go.
As for high idle after starting, it's normal.
Good luck

 

Makes sense. Thanks. The battery, terminals, and starter are all recent changes. I can just check the condition of the wires, etc. Is the component that is bolted onto the firewall, where the positive cable is interrupted, the starter relay? It was making a loud clunking noise whenever we turned the key during the no-start issue. Oh, and since we were getting that clunking noise at the component, what part of the starter circuit could we eliminate as not being part of the problem at that point. I am not familiar with the circuit as I don't have a wiring diagram handy. Thanks again.

 

Start from the beginning. 10V is not a good thing to find. Was this measured directly at the battery posts or some other way?

Always use an external charger of sufficient size for the battery in question. 6 to 10 amperes for a typical truck battery. Jump starts are really for roadside emergencies, an alternator is not able to recharge a heavily discharged battery effectively, they will run very hot and may be damaged trying to do this. The internal stator and diodes can burn up. They will charge enough to get things going, which leads folks to believe that is good enough. Anyway, enough lecture, charge it up thoroughly overnight and have it load tested. A defective battery can damage an alternator as well. Check that the belts are tight, and the cables and connections are clean and tightened securely.

 

The clunking you hear!.
It is the start solenoid on the fire wall.
Follow along for why it acts that way under certain circumstances.
Once you go to start position, the battery voltage is high enough to pull up the solenoid.
Once it closes through the heavy lead to the starter, the voltage drops from the higher current attempting to be drawn by the starter.
This causes the voltage to reduce causing the firewall solenoid to release.
The cycle can keep repeating as the clunk you hear.
It is highly suggestive of a poor cable connection, a faulty cable or even a faulty battery 'intercell strap' as a high resistance in the circuit at some location..... before …...the starter solenoid point in the total circuit.
Also this condition will modulate the interior lights if they are on because the system voltage is taking wild swings in voltage level being powered from the same battery circuit..
So that's what your looking for somewhere in the system.
Good luck.