My '96 F150 has a strange voltage problem, when the truck starts, the voltage is normal, but when you roll the power windows up, and you keep pressing the window buttons when the window is up, the voltage goes so low it almost kills the truck, than it goes back to normal voltage, it's been going on the past 2-3 days, and once in while, I turn the key, and it won't do anything, it won't even try to start, and none of the indicators turn on or nothing, none of the lights will work, nothing will work, than I disconnect the postive battery cable, and than reconnect it, and the truck fires right up with no hestitation, all the lights and accesories will also work, but the voltage will swing slightly when you first turn on the lights and/or the heater controls, and the power windows at first will draw voltage real low. I'm wondering if the postive cable, since I can't seem to keep it tight enough, I wonder if the cable gets loose enough it cuases a problem with the battery and cuases a voltage problem, could the direct connection of my stereo to the postive cable draw too much power? there seems to be a strange voltage problem here. Also, before I replaced the ignition tumbler today, when firing the truck up, none of fan settings would work, but I would turn the tumbler a hair back, and the fans would kick on, but I did that again last night, and the voltage freaked out, and killed the engine when I put the lights on, and after another start, it sat idling with the heater running, and the engine died and I had to pull off the the postive battery cable off and put it back on, and the stereo kicked on, and the truck started right up, and than it proceeded to do the voltage hop when I rolled up the windows and it went back to normal and I drove home with the heater/fan working just fine, I wonder if the ignition switch could be part of the voltage problem, or the postive battery cable, maybe the voltage regulator? Any help would be much apperciated.

Thank you
- Andrew

 

If it was me I would fit a new pos. battery wire and a new ign./starter switch. Assuming a `96 is the same as earlier models the ign./starter switch is on top of the steering column under the dash and connected up to the key switch by a thin rod.

 

Thanks, I'll try that, see if it helps

 

I would check for a weak battery or bad cables before replacing any other parts.

 

LOL


Your Post sounds to the "T" like mine a few months ago....

my battery finley died...

Walmart has there BEST battery for like 80 bucks.

it has a 3 year garente with NO useage cost....

do your self a favor replace the battery B4 u fins your self on the side of the road

 

also remember to REPLACE the post while your there...


and remember that DC reads from nev to postive

So the NEV terminal is more importaint than POS

 

I would probably start by tossing out your + cable and replace it with a brand new one. Next check your - cable for connection and corrosion problems. Make sure that it's all tight. Check the main ground to the body from the - post as well. If your still having problems have the battery load tested by a pro or your favorite parts house, whichever you prefer. Bohiaa could be spot on with the dead or dying battery thoughts.

Good luck and post back if these inputs don't help ya.

Cheers!

Mike

 

My '94 F150 had similar symptoms. I checked the voltage on the battery when the engine was off and only had 10.5 volts. The battery was from WalMart and was still under warranty so I took it back. The new battery took care of the problems. Also when the truck is running check the voltage at the battery terminals to see if it is getting charged. SHould have 14-15 volts if the alternator is working.

 

Bohiaa - I'm pretty sure that dc flows from positive+ to negative- becuase negative is your ground and both sides are equally important becuase if one side has problems the whole truck has problems.

 

i worked at a battery place for 3yrs, and i would load test the battery, if good pull the alt and have it bench tested under a load (may have blown diodes in it) will cause it to work but not well under a load, and as stated above voltage while idle should be 14 to 15 volts.. mid 13 volt is a problem, also could be regulator not regulating...