No power to anything

[zekew64]

Hey all. I have a problem with my '92.

Here's what happened. Before Christmas, I went up northern Illinois; I live in southern Illinois. Truck ran just fine. We have a bad cold snap here, where temps plunged into the negative teens. Kills the battery, although I disconnected it to keep it from draining, due to parasitic draw.

On my way back, I lose my keys in Chicago -- both sets (D'oh!).

Have a local locksmith come out, and he makes new keys by "impressioning" them -- basically, get the tumblers to rub on the new key to find out where to cut the key at.

Problem is, I have no power whatsoever to my truck, even in run. Lights won't come on either. I replaced the battery because it had no CCA (cold cranking amps). Bought a new battery, still no power. Thought that the battery might have power, so I pulled the light switch; no power through the lights either.

Question is, what could have caused a total failure for electrical power? The only difference between before Christmas and now is that the battery had no amperage, and the keys had to be replaced. Could the ignition switch itself have to be replaced?

 

[RonD]

Dome light, Brakes lights and head light/parking lights are not on the key switch, so if they are not working then you are not getting power to the "Power box" under the hood.
There should be one large Red cable from battery to starter solenoid on fender.
On that same post on the solenoid there should be two other smaller wires, one will go to the alternator, the other will be to power the "box", which powers everything else.

 

[adsm08]

Also, crappy battery can mess up the metal in the cable ends and make bad contact. Get a cleaning brush, clean your terminals and cables and try again. I have to do that every few months in my BII because it was run for a long time with a weak battery and the cables are messed up.

 

[zekew64]

First, the terminals on the new battery are clean.

Second, the positive harness for my truck doesn't run to the power distribution box. The positive side of the battery only has the starter relay, the starter solenoid, the starter motor, and the battery itself. On the starter relay (fender wall), there is a wire for the clutch interlock system.

I was told by Autozone, however, that the ignition switch that switches everything on and off might be shot, as if the switch goes bad, then you won't get power from anywhere. Basically, everything but the starter motor is wired into the negative side of the battery.

Is that what I might have to replace?

 

[RonD]

Where does the ignition switch get it's 12volts from?

"The positive side of the battery only has the starter relay, the starter solenoid, the starter motor, and the battery itself"
It comes from somewhere, and that's the place you have the problem, ignition switch is on a fused circuit, so you are missing something coming from the + battery power.


Do the head lights work?

Do the brake lights work?

Lights do not get power thru ignition switch, these are fed directly from the battery + just like the ignition switch is, usually their fuses are all in the same place in the engine compartment.

So there should be a wire from the starter relay(battery post) to the power box, that would feed all the systems 12volts, lights and ignition switch.

 

[Andy D]

Get a meter or a test light and start from the battery posts and work toward the starter. If you jump the solenoid does the starter crank?

 

[zekew64]

I think I may have found the problem -- on the starter relay (on the fender wall), I had literally a 1/16" gap between the end of the wire, where it broke off, and the wire end that was still held on with the nut. In essence, the power was never reaching the starter relay at all. Hopefully, I get this wiring issue fixed, and can see if I can start my truck.

 

[Mark_88]

Been there...done that...amazing how these wires can simply break off over time...glad you figured it out...you can probably just clean the end of the wire and crimp on another connector...

Remember this and always clean your battery terminals and inspect the wires once in a while with the wiggle test...a bit of PMS (preventative maintenance service) goes a long way...

 

[zekew64]

What gets me is that it would completely explain my problem...no power to the box under the hood, no power to the box in the cab.

And, if it wasn't for RonD (speaking of, RonD, a BIG SHOUT OUT TO YOU for helping me out with this! :thumbs up: ), I would have never thought to check the starter relay. Although, I might have caught it if I had been testing it with a continuity tester. As it is, when I was doing that, I kept getting a "good" continuity check, and yet, didn't have power. So what that told me was that it had to be in the wiring from the battery somehow -- which is when I started to test the different wires at the relay. Lo and behold, no power through the wire that is directly from the battery itself.

I have it repaired now, but I have to tell you -- Ford is really weird with our wiring harnesses, in that they are 8 ga. You have to go to Lowe's or Home Depot to find a replacement wire, and even then, you'd be better off to go to an electrical specialty store to get the connectors you might need (although, a 10 ga. connector has worked for me -- you just have to rotate the connector onto the wire you're repairing, before you crimp it and heat-shrink tube it).

 

[turbo2256b]

Battery cables can corrode sometimes a few inches up the wire and loose contact. Inline fuses also can crap out. All of them usally connect to the starter solinoid. Worst time finding a bad wire was my 86 dually with a 460 last year for a carb. Took me 3 days to find the issue. There was one 4ga hot wire that some 1 foot from the solinoid spliced into 2 inline fuses. The two fuses powered everything. It was all hidden under factory tape rap.
The 4ga cable had about 1 1/2" of green crud inside the isulation before hitting copper wire.
It blew my mind as this must have been like this for years.

 

[straycat]

I have taken out a starter relay and all my power is still there. I had lights inside and out. Sounds like there had to be another issue. Clean your fuse block area and check the battery cables all the way to see if there is not a small break some where. Won't hurt to check.

 

[zekew64]

The relay is on the fenderwall. The issue is that one of the wires that is directly connected to the battery was broken, so no power could go anywhere. I'm going to put it back in (the positive/starter harness) tomorrow, and see if that fixes the problem. I hope (fingers crossed) that I don't have to replace the actual ignition switch. That thing is located in a PITA location under the dash.

 

[straycat]

It has to be a broken wire somewhere as I stated. That is always a fun thing to trouble shoot...lol