I have a 1997 4.2 f-150
I drove it to work the other day, and came out 15 minutes later to run an errund and it would not crank. With the key off, I could hear clicking sounds coming from around the fuse box on the inside. When you turn the ignition switch to the run position, the lights on the dash are dim for a while, and then become bright. When I turn the switch to start the truck, there is a click, and the lights in the dash go dim again.

My first thought was dirty battery posts. I cleaned them, and still had the problem. I called my wife to come and bring our other car, and while she was there we tried jump starting the truck. It worked. I followed her home, and I turned off the truck and tried to start it at home, and I had the same problem.

I put a charger on the battery, and in less than 3 minutes, the charger read fully charged. The battery is reading 12.7 volts.

I removed the starter, and had it tested, and it is still good.

I bought a new termanal lead for my neg. post on the battery because it was looking a little bad, and I was thinking I had a bad ground. Still have the problem.

I really feel this is a simple problem with a bad relay or something of that nature, but I was hoping someone else had been through this.

The clicking noise around the fuse box seems it should be a good hint, but I can't seem to figure it out.

It is not hydro-lock. I have already been through that 4 years ago at 123,000 miles.

C. Davis

 

For S&G , try a diff. battery, pull the one from the wifes car and give it a try....could be that easy..

 

Correct no-load voltage for an automobile 12V battery is approx 14.7 volts.
Check the no-laod voltage at your truck battery and compare to the no-load battery in your wife's car.
If you have 12.7 volts no-load, I think you have a bad battery.

If you can, put a DVM on the battery and watch it while you try to start the truck. I'll bet the voltage drops to a very low level. (4,5,6 volts?)

 

I think, but hate to contradict brian, that a good battery reads at 12.6ish, and it's about 14.6ish while installed and with the engine running (with alt. running)

I work at SEARS auto center, and that's typically what I see when running an electical system test on the battery.
Under a load, such as cranking, the batt. should not drop below 10.5ish

Also, when I was a car audio fanatic, i used the 12.2off/14.4running principal when finding such things as amperage and approriate fusing.

That's just the understanding that I have....

 

I've always been told that you can't really tell much from voltage, a load test is necessary. I'd tow (or drive, if possible) the truck to Autozone or Advance, and they'll be able test your battery, and determine for sure whether it's good or not.

By the way, you might want to have them check your alternator as well, also a free check, that would be a probable reason for a battery to die.

 

Rman,
I think you are correct. Apparently I had a brain fart.
12.7 no-load.
14.7 when running.
I'm still thinking he has a bad battery though.
I'd be sure monitor the voltage during cranking.
That would be a good indicator if the battery is bad or not.

 

At work i've actually tested a battery, and with no load it was 12.5ish (normal), and under load it'll drop to 10.5ish (normal), but the machine will condemn it BAD.

I think there are other factors to load testing, like voltage recovery from a load, and other things. But i swear, i'll be testing a battery and about to tell the customer that it looks good, and the machine will just be like "gotcha!"

Best bet is to run to Autozone or whatever like Crazy said, and get a free test. It's $9.99 at my work (SEARS) including drain test, alt. test and starter test, which is usually pretty obvious.

Your problem, of it clicking and interior and dash lights dimming, sound like a battery problem to me.

you said it charged for 3 minutes, and it read fully charged, 12.7 volts.
It may have carried a surface charge, which sometimes our machines don't even pick up, from jumping it then running the alternator. It could even be a dead cell.

99% of the time a vehicle doesnt start, but starts upon jumping it, it's a battery problem. I've run hundreds of battery/electrical tests and that is usually the case. The other 1% is an intermittent starter problem.

If you really feel it's a relay, which i doubt, swap it out for the same relay elsewhere that won't wreak havok if removed, i.e. don't remove your airbag or abs relay and try to start your truck, you may throw a code and have to have it cleared later....

hope this helps,

rman

 

Thanks for the responses. I just got in from hunting this morning, and put the meter on the battery while my wife tried to crank the truck. The voltage dropped down to about 4.5 volts from 12.5. I went and bought a new battery, and that fixed the problem.

I guess what threw me was how fast the battery went. I guess now I know how to get to the solenoid wires for next time the starter does actually go bad. If anybody hasn't had to do it, I found it best to go through the wheel well.

Thanks,
C. Davis

 

motorcraft batteries, no matter what everyone else says, i think they last a pretty long time. I've seen them in trucks for 8 yrs plus.

Honda batteries, and the panasonic batteries in toyotas, typically die down real fast.

rman