I have a 98 Explorer XLT 5.0 AWD that had a battery light come on. My wife was driving it at the time, she called me and told me she made it less than a 1/4 mile and it lost power (would only idle). Checked it out the battery was bad so I put in a new battery and the light was still on so I checked the fuse it was blown (#14 PDB) replaced it. Took it to Auto Zone to get it scanned and they said the alt it not working in range it needs replaced (it was the original) so I put a new alt on, so far so good. Later on the next day the wife was at her girl friends and I get a call the X won't start, so I grab the battery charger and go check it out. The battery is dead checked the fuse and its blown again, replaced fuse(#14) and charged the battery go back to the zone the alt tests bad. I go home pull the alt exchange it/replace it and the battery light is on again, blown fuse again. Check all the wiring for any chafing, everything looks good do an electrical test with my multi meter everything checks out okay but it keeps blowing fuse #14 in the PDB. I have had 2 techs over whom work on auto electrical and there both lost. I had a remote start put on last x-mas for the wife and we were thinking just maybe but thats not it and to even make things crazier the front wiper washer wouldn't spray for the longest time it just started working again and I also noticed a blown fuse in the cabin #15. I have done automotive electrical in the past and my 2 buddys do it for a living but we are lost and I really just don't want to start replacing parts to guess what maybe wrong....I may replace the ignition switch and the multi function switch but i'd really like to find the source first.... ANY HELP WOULD GREATLY BE APPRECIATED....


Bill

 

1st off you should hunt down why the fuses are blowing. You need a wiring diagram to do that effectively. You may have two issues so take care of the fuse blowing first.. Charging voltage 14.5 engine running fully charged battery...Battery if good will read 12.5 after headlights on then off for 30 sec's to kill the surface voltage...Actually 12.7 is fully charged. See what doesn't work on those fuse circuts that may give you a clue to what circut item is causing the short...


Dick

 

I've got the whole truck wiring diagram, I have alldata. Done all that, thats why were are scratching our heads it doesn't make sence because everything is checking out okay but it keeps blowing fuse #14 in the power dist box.... I know there is a problem but we are beating ourselves to death trying to find it.... No broken or chafed wires.... There has to be a dead short somewhere but ?


Bill

 

I'm sorry but you have to isolate things. I've been doing this for 35 years. Its easy for me I was trained in electronics. When does the fuse blow? Put a new one in and turn on the key and try turning on all the things that are connected to it until it blows.


Dick

 

I have pulled all the connectors apart and checked them individually then put them back together and checked them as a unit. You have some time in electronics i'll give you that.... The mini-fuse blows either after a few mile drive or right after starting. The mini-fuse in question is for the alternator system #14 in the power dist box under the hood. Both wires that go to the mini-fuse are from the alt, one is to the regulator (Y/W) the other is to the generator B stud (B/O). Now the other wire connected to the terminal going to the regulator is (LG/R) that goes to the charge indicator lamp on the instrument panel. I tried it again and the fuse blew right away. It doesn't seem to affect anything else when you can keep the fuse from blowing right away. I did notice when I had the second alt on it that if you when over 1500 rpm it would blow the fuse right away but if you stayed below that it lasted for about 2 miles or so. I know i'm drawling at strawls here but ,i'm really starting to get a little frustraighted. I keep having this gut feeling its just something little i'm missing thats why I had my 2 buddys come look at it and they keep coming up with what i'm finding. I'm going to go over the wiring diagram again. I may pull the upper plenum off tommorrow and cut the harness under there open to see if there is something that i'm overlooking. Thanks for your replies....



Bill

 

Disconnect the alt and run the engine see if it blows. I'm thinking????? I'm sure you wiggled wires to see if it would blow. You can buy a gizmo that you put in place of the fuse so you don't use up fuses like mad. I have one they are great it has a circut breaker in there that resets itself. I used it when I was at the dealership...
I have a 99 and 96 ford cd would either one of them be close to your years elec drawing?

 

I think my 99 elec drawing is correct! Fuse 14 Goes to the alt that is your feed. You have a 5.0 correct? The only thing that will blow that fuse Is the alt which I doubt, The fuse holder itself wires touching etc. The connector at the alt. Wire rubbing. Yel/wht wire its short and only goes one place. Its gotta be touching ground somewhere! The engine doen't have to be running and the key doesn't have to be in the run position for this fuse to blow. I'm guessing when the motor is running it moves and shorts the wire,.....


Dick

 

turn everything off disconect the hood light and the neg. batt. cabel with the doors closed put a test light from the neg to a good ground if the light comes on there is a dead short somewhere. start with your allt. cabels first and then its just a matter of going one wire at a time to see if moving it makes the light go out. if so replace it or insulate it with alot of elec.tape good luck

 

I haven't done this as of yet. For some reason there are no parts stores here that have a 30 amp mini circut breaker....


Bill

 

Dick the 99 drawing is very close. Yes the #14 mini-fuse goes to the alt the wires are Y/W and B/O. No wires touching. It has never blown a fuse not running, but with the key on only it has blown a fuse, once or twice, it's more common with the engine running for the fuse to blow


Bill

 

Larry I tried this. Everything is off to my knowledge and there is no hood light, doors closed I put the alligator clip on the neg- side of the battery and found a good ground and yep I have a light, the dreaded short. Now I wiggled every wire I coud get my hands on and at every connection and I got nothing but the light got brighter at one spot checked it out and there is no wires damaged in anyway. Went back and checked it again and the light just stays constant no brightness. I even pulled the harness apart at the firewall and the light stayed on just trying anything. I am having a heck of a time finding this short seeing there is really only 3 wires Y/W, LG/R and B/O coming from the alt. I am going to regroup and start over again hopefully tommorrow, I really don't want to cut all the wires out of the harness but I need this fixed its been way to long fighting this thing.... Dick and Larry you guys have been great and I appreciate it, I feel stupid for not finding this yet, I felt a little better when the 2 techs from the Ford/Mercury dealer were scratching there heads becuse they couldn't figure it out either, but it still is not fixed. Tommorrow is another day and I think i'm going to pull the upper intake off and pull the whole wiring harness out and untape it and go wire to wire to see if i'm missing something, I don't know what else to do....


Bill

 

Only the one wire has anything to do with that fuse the y/w The other wire goes to the battery and is the alt output..Its not linked to that fuse. You should be able to disconnect the y/w wire from the alt and run the engine and it should still blow. That wire is hitting ground somewhere...
Is the engine block grounded? A good connection?


Dick

 

I had somthing like this happen It turned out to be the switch that controles the AC I dont know if your AC works or not but you might check that out. you might check the fuesable links sometimes they can melt on the inside and you wont be abel to find it that easy good luck also I forgot that if you have a digital clock radio you need to pull that fuse Sorry

 

Come on guys there is only one wire on that fuse and it goes to the alternator. Please don't make it any harder than it is ..


Dick

 

Guys I have the positive+ side of the battery hooked up and the neg- unhooked with the test light hooked to it and I have power everywhere thats grounded. I even unhooked the alt completely no wires to it and I have power to both male terminals on the regulator and power to the stud....Still searching.....


Bill