Really Weird Starting Problems

if anyone can figure this out....

When I go to start my 90 full size bronco sometimes, all I get is a click and a power loss.

If I tap the positive or negative lead on the battery, the power comes back, and I can try again to start. IU have cleaned the terminals to death, and have had the battery tested, no problems.

Have alos replaced the fender solenoid (Spelling, lol). Sometimes it is fine for months, or like recently, it happens every time I start my truck.

Sometimes replacing the positive lead or tapping it once will do the trick, sometimes it can take twenty times.

If I turn the ignition to the run position and try jumping the solenoid, it will do the same thing, just click, and I have lost all power...

Should note that when I jump the solenoid, I am able to see a bit of smoke come from the positive terminal on the battery and that same terminal seems to be just a little hot, don't know if this is expected orr if it is a ground problem....

Have a few cold ones ready for anyone who can help

I have same problem on a 1986 Bronco, 5.0 EFI. Had it checked and of course it wouldn't do it for the mechanic all day, I drive it home and won't start after I turn it off. Cleaned up the contacts on solenoid and it started. Drove home today, won't start, it's like a dead battery but I know it's not. Hopefully someone else has had this problem and has figured it out. I'm thinking we probably need to check and or replace wiring somewhere between battery and alternator. I know mine shows charging after initially starting up, but never see the needle move again while driving.

Thanks for the reply... The funny thing is like you said it is totally intermittent... I replaced the positive lead (Cable from postive to solenoid $4.86) on the battery and this took care of it. After examining the lead, found that it had a stress mark on the underside that I would of never seen had I not taken it off. The thing that really gave it away was that tapping on the positive would sometimes bring power back.... Now, onto my next problem...

If this sounds like you, go ahead and replace the leads, they are cheap at you local auto parts store and can save yourself from pulling your hair out....

I have same problem on a 1986 Bronco, 5.0 EFI. Had it checked and of course it wouldn't do it for the mechanic all day, I drive it home and won't start after I turn it off. Cleaned up the contacts on solenoid and it started. Drove home today, won't start, it's like a dead battery but I know it's not. Hopefully someone else has had this problem and has figured it out. I'm thinking we probably need to check and or replace wiring somewhere between battery and alternator. I know mine shows charging after initially starting up, but never see the needle move again while driving.

I don't know if this is any help but we had the same problem (more or less) with a 68' Valiaint. Turned out it was the wireing harness that needed replacing. I found someone that did beautiful work at rebuildng one for me.

Now that you've fixed the leads, you can get fresh starters. (I did have this problem to death, but replacing the leads was a great solution.) The other part is that the starter wasn't starting because it wasn't getting enough juice. That's pretty stressful, and The Man doesn't deliver starters...