Folks, I don't know where to start with this. I think I may have an electrical gremlin. My '97 F-150 Lariat is an almost daily driver w/ ~120k miles. Today threw it into 4x4 to haul some wood around the property. I parked to unload and tried to start after about an hour. Nothing. Completely dead, I'm talking no solenoid clicking, no radio, no power locks, no courtesy or brake lamps, not even hazard lights. Battery voltage reads 12.6 and a jump from my car did not help. Battery and connectors are both new (< 1 year). I also went through every fuse in all the fuse boxes, they are all intact and in the correct terminals.

Not sure where to go from here. Somehow the battery power is not getting to the rest of the vehicle. Appreciate any tips because troubleshooting electrical systems is low on my list of vehicle expertise. Thanks,

 

You have a underhood fuse box. See if you have power in that fuse box on the fuses. A testlight with a sharp probe is good for this. If you have a meter you can use it also.

If you have no power in the underhood fuse box, somewhere between the underhood fuse box and the starter relay is a 175 amp mega fuse. See if you have power on either side of that.

Power goes from the battery to the starter relay. Then to the 175 amp mega fuse. Through the mega fuse to the underhood fuse box. Most of the fuses in the underhood fuse box are hot all the time.

The ignition switch is fed from two 50 amp fuses (#20 and #21) in the underhood fuse box. Then the ignition switch feeds hot only in run circuits in the underdash fuse box. There are some hot all the time circuits in the underdash fuse box, these are fed with fuse #22, 50 amp in the underhood fuse box.

If you start having strange problems with the meter reading good voltage, but nothing still works, make sure to turn the keyswitch to run inside the truck, and then go out and check for voltages again. You can leave the door open also so the domelights try to come on. Sometimes to find a problem you need to put a load on the system, and then check it with your meter.

If you find everything is working until you spring the key over to crank it, then you will need a helper to get in and hold the key over to crank position, while you go out and poke with the meter under the hood. Sometimes you will find the battery reads fine just sitting there, but the voltage drops very low when a large load like the starter is put on it.

 

If you installed new replacement battery cable ends and they are of the chap Chinese painted variety, take them off and scrape the paint out of the connection area where they mate to the original cable.