That said please make sure that the computers are the same part number.

There is a poster on this site called Numberdummy he was a ford partsman and should be able to tell you one way or the other GL.

Rick.

 

Gov, pull some plugs and see what they look like before and after you crank on it. Perhaps the injectors arent openning up also doesnt that 91 have 2 pumps on it. 1 in the tank and another on the frame rail?

 

I'm sure it just has the one pump in the tank and none on the frame. I'll pull some plugs later today and look at them if I get time. I don't think any injectors are opening though as since I drove it home the other day it's never had one hint of starting. I would think if any of the injectors received any gasoline I would have had a pop, spit, or something by now. I don't think any gas is getting to them.

 

I would start to maybe unloom the injector harness and check for bad wires. also go on fordfuelinjection.com to see how to test your injectors i am sure there is a process on that site.

you might also try the ecu from the bronco with the AOD. the rig would should still start but may throw a tranny code or two for not seeing the e4od.

have you checked all of your ground wires?

 

It gets better! Today I had a few minutes before work to look at it. I checked various ground wires as well as I tested all of the fusable links near the battery. I didn't find the Diode yet, what side is it located on? However while I'm sitting in it, just for the heck of it I check to see what else worked or didn't work. Remember, until a few days ago this was a daily driver with no problems. I turned on the radio, turn signals, lights, etc. and everything seemed to work ok. I got back out and noticed the parking lights were still on so I must have forgot to push the switch all the way in. Nope, it WAS in. I tried it a few times, it has the three positions, off, on, and on with headlights but the parking lights never turn off. I think it's possessed. Actually it's probably what ever is feeding the fuel pump constantly is now back feeding the lights as well. I just unhooked the battery and went to work.

 

For those lights to be on they have to be getting a Positive feed from somewhere because the negative is always present, I would suggest hook your battery back up and then start pulling control fuses until the parking lights go out.

That should narrow down your problem wiring to a specific circut.

Wiring can be the most difficult or easy repair the most important thing you must always remember is Electricity takes the path of least RESISTANCE so that said because you haven't blown any fuses the short is not to ground and should be pretty localized.

Also a good rule is to rule out any non Ford wiring ie Plow lights or Radio wiring etc.......

Rick.

 

Well, after I got home tonight I hooked the battery back up and no lights. I turned on and off the headlights and the parking lights stayed on. I unhooked the battery and they went out. I hooked the battery back up and they stayed out. I did it several times and it does the same. I've got a feeling that whatever is backfeeding the lights is also doing the same to the fuel pump. This entire problem happened all at once, the transmission overdrive, the non starting, the fuel pump, and now the lights. The only problem this truck has had in the past is another strange electrical problem. The electric door locks only work going down and only work with the passenger side switch. I've tested or changed the switches and the lock actuators and everything is ok. If I put 12V to the drivers side actuators both sides will go up and down. If I put 12V to the passengers side actuators both sides will go up and down. Maybe that problem has merged into the rest of the system.

 

So next best suggestion is find an auto electric garage and have them take a look for you.

Why I say this is because the guy who lives next door to me owns an 1986 Camaro and he overheated and fried the engine about two years ago, after paying $3,500 for a rebuilt and installed engine the car overheated again this time close to home no damage done to engine.
He asks me to take a look, I did I found the electric fan did not work.
The reason was the fan motor was worn out no brushes left and the spot the previous owner cut into for power to run this electric fan the wiring broke off because it was just finger twisted together and the heat from the bad connection made the wire break. Everything of course was under 5 pounds of electrical tape.

We installed a new fan motor and corrected the bad wiring job and now the neighbour has been driving the Camaro 2 trouble free summers.
I tell you this because if you are not the original owner of this Bronco who knows what the guy before you did to the wiring.


It is sounding more and more like you have wire harness problems either corrosion or shorted, now the thing with your locks could be an interlock switch problem or broken wiring.

You need someone good with a meter and a wiring diagram locally.


Rick.

 

I've got a lot of Harley Davidsons, Fords, four boats, two Corvettes, and a multitude of other equipment. I've probably got at least 50 vehicles, equipment and other things with engines on or in them and I've been my own mechanic for my whole life. The chance of me taking it to someone else to fix has about the same odds of me winning the Powerball Lottery. I'll be the one to find the problem, eventually. As for the door switch thing I just didn't get back to that one as it wasn't that important. But since I can put 12V to the drivers side and both sides worked and if I put 12V to the passenger side and both sides worked I figured the wiring between the doors had to be complete and unbroken or something would not have worked.

 

The diode on my 94 is in the power distribution box with the relays. Standing at the driver's fender looking in the box it is the far left one. Try swapping it to another vehicle. Thinking about the cross feed. Haynes should have the color codes. Having recently opened up the harness from the computer to the coil, I would be reluctant to suggest it. I could not find any rub place and the original wrap was much better than my rewrapping it. Could something have cut the harness underneath and got the pump and tail lights together? Where would they most likely cross? Ford fuel injection has a page of what computer went on each vehicle so you can see if your other vehicle computers match. http://fordfuelinjection.com/?p=17

 

B4hntn, I'll look for the Diode and after it gets above 40 degress (woohoo!)tomorrow I'll get under it and check out the wiring towards the rear of the Bronco. I was really leaning towards a computer problem until the parking lights got in the mix as well. That's when I've really changed my mind and I'll be looking for some sort of short where the 12V positive is back feeding the pump and the lights.

 

What is always hot going toward the pump? Locks, rear window, rear dome light lumbar support. Anything else? Hmmmm. The rear window would be my guess to start because the connector is near the bumper. Do a search for the window wiring as it is a little trickey as I remember. Good night. You will find it. Think about pulling some fuses per Red Ford Truck

 

I wasn't questioning your ability or know how, I was only suggesting that sometimes we need a little help once in a while and sometimes a second set of eyes is a big help.

Once again no offence was meant, I'll leave you to it and look forward to reading what you find is the problem.


Rick.

 

Rick, no offence was taken and I'm sorry if I came off that way, I certainly didn't mean to sound like it. I appreciate any and all help that I can get. Your suggestion of pulling fuses is what I'm actually going to try next. The lights are not controlled by the pull out fuses but whatever is back feeding the system may be on a fuse. So, if I pull a fuse for example for the back window and the parking lights go out then I'll know that's the one that is shorted with the others. Thanks again for your help.

 

And believe me when I tell you I know the wiring problems are the toughest to track down sometimes, I once spent several days trying to find a bad circut on a Raymond forklift when I found it, it was not in the manuals it was a single staple sitting on a hidden terminal strip in the control panel.

Everytime the operator hit a bump or crack on the floor the truck would cut out about a mimute or so later from the staple touching the terminal strip, it never blew a fuse or the computer control card and if you let the truck sit for a couple of minutes it would operate again for sometimes a couple of days.

It almost made me bald from pulling out my hair looking for this Phantom problem.

Rick.