Having a hell of a time with this one.

1995 F150 XLT
300 Straight Six
5 Speed
4x4

I'm not really sure what's going on with my truck, but hopefully someone here can shed some light on the issue. I recently noticed that when I wind my power windows up, my headlights dim. Pretty badly. It becomes most noticeable once both windows are completely up and you continue to hold down the "window up" buttons. But it doesn't stop there. If you turn the radio on, heater on full, lights on, etc. and then hit the window switch, the engine dogs very noticeably.

Thinking my ground was suspect, I replaced the short ground cable going from the battery to the engine bay right near the starter solenoid. No dice. Then I replaced the other ground cable, which goes from the battery down to the frame (where there is a break in the insulation and a bolt on the frame) and then to the starter bolt. (I believe this is the engine ground). I used heavy 2 gauge wire. Immediately after doing so, I drove around for a while, and then went to the parts store to do a battery test. On the way there, the battery light would come on for maybe a second at a time every couple of minutes, but seemed to stop after I was driving for a while.

When I got to the parts store, I shut the engine off and went inside and came out with a sales guy and the tester. He hooked it up and the battery read dead. I tried to start it up, but upon turning the key everything went black with no power from there. Tried to jump it, no dice. I ended up buying a new battery, and then it started up, and the clerk ran the test. Everything read fine. On the way home, same thing kept happening with the battery light. Today, I went through and sanded that ground portion of the frame to bare metal, along with the ground by the starter solenoid, just to confirm everything was making good contact. The original problem is still happening.


Guys, I'm ready to pull my hair out! Does anyone have any idea where to look next?

 

have you tested your alternator.

 

Smells like the OLD ORIGINAL im assuming ALTERNATOR is dead..take it off and have it tested.

 

f150 beat me to it..lol

 

Yes, when I bought the battery, my alternator was tested. It certainly looks newer, but wasn't replaced under my ownership. IIRC the previous owner said he had the alternator replaced like 2 years ago. Give me a minute and I'll take a pic of the test results.

EDIT: ****. I lost the little slip of paper. During the test, the tech had me turn on my blower, headlights, radio, etc and then hit the gas. The machine, which was clamped on the battery, returned good results. The little slip of paper said the alternator was okay and had a little graph on it.

 

it could be a week old alternator and it goes bad. also even testing parts wont always show that they are bad, we had a starter that tested fine 3x before it tested bad.

it could be the voltage regulator.

 

Don't forget the positive cables and both terminal ends. It is possible for corrosion to be inside the wiring. I had similar issues and ended up replacing the terminal ends and cleaning all my cables. Whenever my truck would lose power completely as I turned the key, it was because the POSITIVE terminal/wires didn't have a clean connection.

 

As forge said the cables. I went a different route and replaced battery cables completely, really wasnt that much thru Ford. PO had replaced ends but corrosion had crept inside the cables.

 

I have owned two 1995 ford f150's and both of them did this. My alternators were fine. It's just that ford didn't compensate for someone to hold down a button and force the window motor to keep pushing up. Newer windows don't do that from what I recall. I wouldn't worry about it. The only times this happened when was you were holding the button down so I would just refrain from doing that....lol but if this happens when just rolling it down then defiantly get a voltometer and see what your readings are.

Edit: didn't read all of it just the first section my bad. Sounds like you have a short. Have you installed anything electrically new? Sound system? Lights? This could be your problem if not wired corectly

 

Thanks for the input. The lights dim slightly when I'm just rolling them up, but it's really noticeable when they reach the top. You're probably right, there's a good chance it's always been like this and I've just never noticed until now.

Nothing aftermarket, other than a few gauges, but I disconnected them all to rule out any fault in my wiring. I think I'll replace the + battery cables since I did the other ones. I'm sure if they're corroded enough, the increased resistance could hamper a good current. Not to mention, the alternator doesn't connect straight to the battery, it goes through the starter solenoid first.