I have a V8 triton 1998 F150. I have had a brand new alternator installed and have a three day old battery under the hood. When I hit a curb or sidewalk edge hard. the truck will become impossible to start once i turn it off. When I turn the ignition I hear a click sound and then the truck loses all electrical power. I will fidget with the battery terminal to get electric power back on and then when I turn the ignition again a click sound occurs followed by complete power failure. I am not sure where the solinoid switch is located and if it needs replacement. but the problem seem bigger then that. It might be two wires at the base of the alternator shorting out. I need help.

 

Let me see if I have this correct :
After hitting a bump, the truck continues to run.
When you park it and tuen off the key, you hear the click ?

You mess with the battery terminals and power comes back, and when you turn the truck back on, you hear a click and get power failure again. i.e. the truck does not start ?

How do you get the truck to start again ?

Could be a few things, the power feed from the battery to the starter is right on the firewall by the battery on my 01, and this might have loose terminals on it ? Have you tried tightening them ? I think it is a 10 MM or 12 MM nut.

Just a few things to check to make sure the battery terminals are bolted down correctly, prior to going replacing stuff. The other SWAG is maybe there is a broken mount in the battery, and the plate is movng around, and messing with the wires is causing the plate to go back into place ?? Huge guess at the moment, let us know if you have tightened all the connections enroute for the pos and neg leads, and what you have to do to finally get power to come back on so you can start the truck again ( also if I have the order correct ).

 

The solenoid is along the fire wall (top) on the passengerside its usually under a plastic cover. I had a similar problem the truck would not start i would get the clicking noise the only difference was that my electrical would not cut out like yours. Replacing the solenoid cured my problem. AutoZone 10 bucks.

 

I have had the solenoid replaced that is not the problem. I took the truck to the local dealership and now they want to pre form a electrical diagnostic. I would like to avoid this for cost reasons. Might I add that this truck has been purchased used and that the ignition is damaged and will be replaced before the diagnostic test is to be done. THe ford truck technician said that someone might have attempted to steal the truck and the sudden cut of is the trucks theft protection in action.

 

Is there enough power in the battery to run the headlights?

That clicking you hear is probably the solenoid. It sounds like the solenoid is good and is passing current to the starter but the battery does not have enough juice to turn the starter. The starter then drains dis-charged battery even further.

It sounds like something is draining your battery when the vehicle is shut off or the alternator is not charging the battery properly.