No voltage

[YJEric]

After a tough day on a recovery trip and a lot of bouncing around on rocks, my battery broke free and must have shorted out or broken a connection. After shutting the truck off it would not start, in fact there was no voltage anywhere, as if the battery had become completely disconnected from the electrical system. Starts if you apply 12v directly to the starter but not if it is applied to the battery terminals. No lights and no voltage anywhere in the vehicle. I checked all connections today and all seem good. Is there a fusable link or something? All fuses are good.

 

[Opera House]

Main power distribution point is one of the the large terminals on the fender starter solenoid. I would suspect that there is a break in the wire from the battery to this solenoid. The alternator output also feeds to this point. Since it continued to run with "no power", it is likely that all the electricals beyond this point are fine.

 

[Bruces expo]

did you check the solenoid mine did the same thing and the wire runnin for the bat to
the solenoid. mine was loose i tightend it up it started. workin fine since then
good luck
bruce

 

[YJEric]

Makes no sense

OK here is what is happening now. I know a little about ohms law and electronic theory so this has me confounded. There is wire leading from the battery + terminal to the starter selenoid. It is thick, one is thinner and it leads back into the wiring harness. Both are connected to the rear terminal of the selenoid. If I bypass the heavier gauge wire with a new wire from the + term to the rear terminal of the selenoid the starter engages, with no key in the ignition and still no power to anything in the truck. How can this be? if the wire comes right off the battery how would bypassing it cause the starter to engage? Why would there be a direct connection that leaves the starter engaged all the time? I assume that the heavy guage wire must be broken or the starter would run continuously. But this is how it's wired. Is my starter selenoid shorted out? Would that cuase no voltage everywhere in the truck? How would that cause the heavy guage to be open? It seems to be intact. By the way bith those wires are hard to see because they are encased in a rubber boot that has part # M-14181 UT. The fron terminal of the selenoid has 2 wires that say fusible link on them and goes into the harness. bypassing them did nothing at all.

 

[Opera House]

Close, but ho cigar. From the battery, there is a heavy wire going directly to the starter. Also a smaller one going to the fender solenoid. You jumpered from the battery to the wrong terminal. That one went to the solenoid on the starter. Try connecting to the other one.

 

[YJEric]

Diagram

 

[YJEric]

Found it!

The rubber boot (M-14181) seperates the heavy guage and light guage wires to 2 different terminals on the solenoid. It has a tab which connects to the front terminal and routs the smaller wire to the rear terminal. The tab broke off in the rubber and that's why I was unable to see it. Opera House you were right, thank you for all your help. The boot half broke off when the battery broke free and slammed against it.

 

[Opera House]

The things that get hidden under plastic! I should mention to be carefull that you get the alternator output wire on the terminal that goes to the battery. I know of four cases here where the alternator wire was put on the lug going to the starter. Everytime the engine was started, the starter would keep turning. Once the egine was running, the alternator would supply power to the solenoid on the starter.

 

[YJEric]

Good to know

I think I've got it now, starter works fine, electrical system is back to doing what it should be. Thanks to your help, I fixed an electrical problem with no meter and no wiring diagram that was all hidden in a rubber boot that really didn't need to be there in the first place. This forum is invaluable to Explorer owners. :exporange