I could really use some help here!
I have a 97 F150, less than 100K miles, is driving me crazy. I'm real close to taking my plasma torch & cutting it up into tiny pieces.

The truck starts & runs fine for a month or two at a time. Then, one day, it decides it's holiday time. Turn the key, click, nothing.
Had the starter replaced about a year ago, was fine for a few weeks, then started doing it again. This truck runs great when it's running! When this happens, if I roll it, it starts & runs fine, just won't turn over on it's own.

Okay, so it wouldn't start, I jumped it, took it to the dealer. Parked it in the lot, they looked at it and it started fine every time, couldn't duplicate the problem. Removed, cleaned & replaced the wires to the starter. I picked up the truck, went back to work, went to leave 2 hours later, truck wouldn't tun over. "Mechanics" at the dealer know nothing.

I've replaced the solenoid twice, starter once, neutral safety switch once.



If you look at the starter while trying to turn it over, sometimes you can see an arc, like a bad ground. Took the starter out, wire brushed and sanded all contact surfaces to insure a good ground, started about 6 times after, then nothing.

If you let it sit for about 24-48 hrs after it won't start, it will usually turn over the first time you turn the key, but once the ignition switch is released, it won't turn over a second time.

There's one other odd thing. If the ignition switch is in the on position, not running, the radio turned off, there's a static sound through the speakers, usually every 5 - 15 seconds or so.

Anyone got an idea? Sorry about the length of this, but I've about had it.



- one more thing... I've had it to 3 other repair shops besides the dealer in the past year, two of those shops more than three times each. Everyone gets hung up on the "bad ground" and doesn't seem to want to go beyond that. Now i've spent more money than I paid for the truck.

 

I'm thinking it might be a bad ignition switch.

 

You think, even though there appears to be (at least some) juice to the hot side of the starter?

 

Sometimes it starts, sometimes it doesn't. That means that there is enough juice to the starter to make it turn the motor, but sometimes it's not getting the signal telling it to engage. I would've said check the starter solenoid, but you've already replaced it twice. The next step back up stream is the ignition switch.

 

You know that the started doesn't have a ground strap(in this case it wouldn't hurt to install one). It uses the starter body as a return path to chassis ground. If you have high resistance between the starter body and the attachment point at the block you'll see arcing. There are two ways to do this. Begin at the starter and work backwards to the key switch or start at the key and work toward the starter. Check all the high current connections. BATT, solenoid, starter and even the heavy gauge wire running from the relay(solenoid) to the solenoid on the starter itself. Are all the terminals clean and tight? Are the crimps tight? You need an assistant to do voltage drop checks when it malfunctions. You have to check point to point at the time it fails.

 

I agree. Extra grounding would be a good idea...

 

I'm having the same symptoms on a 1999 F150. Did you ever find out what the root cause was?

Thanks,
-Dylan

 

make sure your negative terminal is properly fastened down, take a cresent wrench and scrape the terminal thats what i had to do on my '03 f-150

 

also look a the groung on the fire wall its the one next to starter relay if u move the wires a little and it starts then the one going to the firewall should be replace it happened to me would cause it to missfire