Electrical Nightmare

therube · Mar 29, 2004

Hey all, I have an 88 Bronco with a 351 W HO and a C6 3 speed tranny ( through that in cause I could). I have an issue where the Bronco will start and run just fine, then about every other week or so, I go out to start her up, and it acts like the battery is dead. When I initially turn the key all the accessories come on, but then all the electrical just goes out and it wont crank or even give the dead battery clicking... When I pull the positive battery terminal off for about 30 seconds and put it back on, it fires right up, and all is good for about a week or so.... WHAT IS GOING ON???? I checked every connection I could think of, and all looks OK. Ya think it is just time for a new wiring harness, or is it something else???

Thanks for the help!!!

Therube in TEXAS

broncogw · Mar 29, 2004

So u dont have to jump it every week when it dies? If you do i was thinking that maybe your alternator isnt charging your battery. Or maybe it is just a bad battery, you could go to advance auto parts or autozone and they will give u a free checkup on your bat and alternator. Or it could be that the ends of your battery cables where they attach to the terminals are corroded and need to be cleaned. Just some ideas post up if none of this works and ill try to help u out.

Justshootme84 · Mar 30, 2004

Yeah, take a second look at the battery cables if they are not brand new. Even though they may look fine on the outside, the inner core can rust and cause grounding/charging problems. It sounds more like the starter solenoid on the fender to me, so check and clean the connections on it. Carefully feel it to see if it's getting hot when it won't start or even crank. I burnt the last one up by spraying WD-40 on it and it fried!!!

Shadow_D · Mar 30, 2004

Welcome to the B Zone therube.
I had the same problem with my 90 FSB. The problem was with the relays on the drivers side fender well. The main problem was corrosion.
You can fix this in one of two ways,
1) You can disassemble every plug and use some sand paper to clean all of the connection. Make sure there is no rust or corrosion at any of the contact points. The use some petroleum jelly and coat all of the connections to keep the corrosion out.
Or
2) You can just replace all of the plugs and relays. These should be available at your local Ford Dealer. Might be a bit costly.

Also do what the other guys are saying about the battery cables as well.

therube · Apr 1, 2004

Thanks for the info guys. I recently replaced every componant in the ignition system except for the battery terminals, and that is on the agenda for this weekend... I will let y'all know how it goes after that! Thanks for the info

Therube in TEXAS

Seabronc · May 23, 2004

I don't know if your year Bronco has fuses or fused links from the start relay battery terminal or not, but if it has fused links try replacing the large one, probably 14 GA which connects to a large yellow wire. They often demonstrate erratic behavior when they go or start to go bad. Another thing to do is check the connector on the driver side that takes the wires thru the firewall, take it off, clean it and put it back on. It is the round connector with a zillion wires in it and a about a 1/2" bolt in the middle.

>-

Good luck,

Seabronc · May 23, 2004

PS that yellow wire is one of the main feeds to distribute power from the battery. Also, there is a black with orange stripe that feeds some stuff, it has a smaller link, probably a 16 GA. :-"

Kennel_Dog · May 25, 2004

I had the exact same problem with my 87 Bronco (including pulling the positive cable off and replacing it). I also changed everything in the ignition system and guess what, it turn out my positive battery cable was shot. I replaced it and have had no problems since.

Gunner · May 25, 2004

i had the same problem to i wish i was just the battery cable. mine turned out to be the neutral safety switch going haywire. just replaced it and everything went great.

ben johnson · Dec 3, 2004

I'm having the same problem,but when I turn my key, it trys to crank but its like there isn't enough juice to turn it over. Just like a dead battery. Replaced battery yesterday still the same. Replacing negative lead tonight.