I have a 1995 Bronco 351w auto. I have been driving it around all day with no issues, now all of the sudden, it won't crank. Actually it won't do anything, its as if I'm not even putting a key in the ignition. I waited a bit and came back, put the key in, lights came on, then I turned to crank and everything went dead again. Any ideas?

 

The battery shows 12v when checked across terminals. However the truck gets no power what so ever. No lights, no horn, anything. I will try and start checking the grounds and power hook ups. Could this be a relay or sensor gone bad?

 

How old is the battery? How are the battery connections? This is where to start first.

 

I dont know how old the battery is, I was planning on swapping in a optima and new cables eventually. I just got the truck bout a month ago. The truck currently has a real lame high guage ground from the battery to the truck while a 4 gauge to the motor.

 

Just had the battery tested. It showed 784 CCa so that shouldn't be the issue. I got some battery cleaner so I'll go over the terminals as well. I just cant see that I wouldn't have some sort of lights or power. Something so sudden and so severe should be fairly obvious to find a cause.

Ok well after reinstalling the battery, and I put the key in the acc/run position the lights came on. Though, as soon as I turned to start/crank everything went dead again. Could this be some sort of antitheft being triggered? I would think that'd olny affect the starter circuit tho, not the entire electrical system. Its as if there isn't a battery in at all.

 

Have you tried a remote start to see if it will start? Do you have another battery you could try?

 

I am going to try and jump it with another vehicle here and see if that helps. what do you mean by a remote start?

 

It won't start even, when being jumped. I also put a brand new optima battery in, and its having the same issues. I'm gonna tow it into my garage and recheck all the connections. What about the starter relay on the fenderwell? Could that cause this? Also the PO painted over everything there, wires and all, makes it a pain to trace wires.

 

Thats what I was wondering about with the remote start. You can install a remote starter switch to see if it turns over. If it does it may be in your ignition switch. If it doesn't it may be your starter relay. I know that the starter relay needs to have a good ground, so you may want to pull it off and clean the area where it bolts up to see if it helps. Had any problems with your starter lately?

 

I've had several F-series in these years come into the shop with this issue, Some were loose connections but several had bat battery clamps, If they are factory cables and clamps and all other connections are good replace the battery post clamps, The factory ones corrode in-side the clamp, Many times this cannot even be seen. Seen a LOT of these cases, even people that have replaced starters, alternators, batteries, and end up so frustrated, and it turned out to be a 3-4 dollar fix. Hope this solves your issue, Let us know.

 

I haven't really had any issues with the starter. I may have to look into a remote starter switch. But assuming that switch is bad, would it affect headlights and such?

 

I will try this first thing in the morning. I was debating replacing the cables all together. Thanks

 

It's easy to try that starter relay, jump it by creating a connection between the two threaded terminals (a screwdriver will work just fine), if the engine cranks then you have found your problem. Sometimes they just get stuck, hit it firmly but softly to let it loose.

 

If your lights and everything go out when you turn the key and the battery is good, It sure sounds like a loose connection or bad battery post clamps.

 

yeah, most of the time I don't even get the lights to come on, just nothing. But I'm hoping it's the post clamps.