Hello, I just bought a 99 f250, superduty, 5.4 gas, 5spd, 4x4, reg cab. I bought it with the clutch out for a good deal and havent had time to get it in.

My problem is when the truck was deliverd the guy said the wipers didnt work...well they do now..makes no sense? Next...sat morn I'm headed out to put the clutch in it..truck running I cut the headlights on and the truck dies. When I say dies I mean like someone pulled the batt. out of it, absolutly nothing.

I thought it may be the alt. so I charged the batt. put it back in and started the truck. Pulled the hot wire to the batt. once started..all good, alt. is fine. So I cut the headlights on again...DIES, and nothing again.

I proceeded to check for obvious malfuctions (fuse's blow/burnt ect.)and nothing. I let the truck sit for 3hrs+ till my pop's got here (ASE cert. mech) and he starts the thing rite up like nothing is wrong?????????????? We looked for stuff and checked, and looked and checked, trying to make it do it again...he says "I cant fix what isnt broke" could not get it to do it again.

I have tried for 1 1/2 days every cuople hours to get it to do it again with no "luck" I'm worried it will happen while driving down the freeway or something and hope someone could shed some light on it...thanks in advance

-Josh

 

Sounds like a ground problem. Check all the little ground wires you can find leading from the battery neg terminal, and ones leading from the engine block to the firewall.

Usually the headlights are grounded to the front radiator support. There probably are other things like relays and and stuff also grounded to the frontend sheetmetal. When the headlights receive power the headlight switch, the power goes through the bulb, and then to the sheetmetal and finally to the battery neg.

If your frontend sheetmetal is not grounded properly, and you turn the switch on for power, the current goes to the bulb, but then can't find a good correct path back to the battery neg. So it may find another component like a relay or the computer that also uses the sheetmetal as a ground, and will try to go backwards through it to find it's way back to the battery neg. When this happens, it can kill the other component till you turn the lights off.

If this truck was ever wrecked, or another engine installed, someone may have left some important ground wires off.

 

Thanks you man, I was hopeing you would reply. I have searched a bit before I posted and saw your the "wire guy" here.


That also reminded me that in the mess of it I cleaned the main ground from the batt. to the framerail, it hasnt done it since. The truck has 250k on it, the motor was replaced at 170k and the wiring is a mess thru the truck (mainly under dash). I'll go thru and check grounds as well as clean termainals, and look for the obvious. Thanks again, and post up with any other ideas.

-Josh