I went to start my truck on Tuesday morning. Turn the key and all the lights came on but it wouldn't turn over. Tried that a couple times but nothing happened. So I put a wrench on the solenoid on the firewall and it would try to turn over. The start was changed out 2 years ago and the solenoid was changed at the same time. It was -10 when I tried to start it so I thought the battery didn't have enough cranking amps and bought a new one. Started right up. Then I went out to start it yesterday and it wouldn't start again. Had my fiance drop me off and a friends house. Got home an hour later and it started right up. So I took the wires off the starter and solenoid to clean them. Figured all the salt in MN got to it. Went out this morning and turned to key forward, didn't start instantly. Took about 2 seconds and started right up. Would it be my ignition switch, FPDM, or fuel pump? I don't know where to start. Sorry for the long question but was hoping someone had the same problem and could point me in the right direction. I've used this forum before to diagnose problems and save me money. Thanks.

 

2001 F150 4.6l 129,000 miles. Start school next Monday and it's supposed to be a high of -15 so I'd like to get it done this weekend.

 

It sounds like you need to go another couple days to see if your cleaning of the cables/posts work.

My truck cranked over slowly today in the -15 we had in central MN this morn.

From what I understand, the issue is that it doesn't turn over or crank when you have the problem. This would rule out fuel pump because the starter/relay/battery don't care if it has fuel when you turn the key. Batteries you buy at the store usually aren't fully charged. Get a charger on it.

 

Yea. Doesn't turn over or crank. That takes the fuel pump off my list. I put the new battery in and drove it around right after. No problems until the next morning. I'll check the battery when I get home. I did check the other battery across the terminals and it showed 12.1 volts. That's why I thought the battery didn't have enough cranking amps.

 

That is not a good way to determine cranking amps.

That may help determining charge but you would need to know what the resting voltage of the battery @ 100% is to determine charge.

Put a charger on it and watch until it gets to 100%. You don't know, it might be that your alternator is not up to par and can't charge the battery enough.

A low charged battery can "freeze" over night basically render it useless. Trust me, I changed out 3 batteries one winter in my car.

 

Sounds good. I'll try that. The old battery said 610 for CCA. The new one is 850. I changed the alternator out about 2 years ago too but it could be going bad. Any info is appreciated.

 

Another thing. I tried starting it over the solenoid on the firewall and sometimes it would start and other times it wouldn't do anything. Does that give anyone anymore info? I am at work until 3 and hopefully it starts. Does that sound like an FDPM problem? I hope to get this figured out tonight.

 

So it will crank over and run sometimes? Does it "click" when you turn the key? I suspect a dying starter OR is your battery dying, I couldn't understand the original posts

 

By -10 and -15 he is talking outside temperature in Fahrenheit.

 

Sorry. It's tough to explain my problem over the internet. I turn the key forward and it won't start. Try it again and it starts right up. I'm thinking the ignition switch but I have not idea. If I bring it in, I'm sure it will have no problem starting. I could start it right away three times in a row and the fourth time the problems starts again.