I've had this Ranger about 3 years now, only had this problem like once. But now kid is driving truck to school, she's had it like 4-5 times, twice in the last 2 weeks, so I guess I need to figure out what's wrong.

Open door, dome light is on, turn key, click in engine compartment, all electrical is dead (no dome light). Pull a battery cable off, put back on, lights come back on. Sometimes this fixes it & starts, sometimes it does not. Sometimes wiggiling/pulling on the cables fixes it.

Battery is brand new, alt tests fine, 14+ when running, no CEL or codes, new battery terminal connectors, original battery cables. Not a yankee truck (ie no road salt, etc)

Today this did not fix it; jump start did not fix it, but I did remove the neg cable from the battery & connected jumper directly to it (on the Ranger not the donor) and it started, & drove home fine. Get to garage, turn off, try to start, again everything's dead.

Ideas's where to start?

 

Make sure the battery cables are on really tight. My Ranger did this after the dealer installed a new battery. Had them tow it back! Driving vibrations had loosened them enough to break the electrical connection.

 

The click you're hearing is a relay. There's a relay that kills the battery saver circuit (interior lighting, radio, possibly power windows and locks) upon turning the ignition to 'start' and then resets afterwards. However, this relay does not kill absolutely everything.

In the power distribution box underneath the hood, relay number 6 is the starter relay. I would start by swapping this relay with another relay in the box itself. If the problem moves or goes away, you've found your problem.

The fuse for the ignition and starter is maxi fuse number 5. It's going to be a large (physically) 50 amp rated fuse.

Also, confirm the battery is good. take it to an auto parts store, they'll check it for free or very little, like autozone. A bad battery can cause a multitude of problems, even po300, random misfire. The battery is the beginning and end of the electricial system. Also make sure the copper wires themselves are clean and snugged in the terminals firmly.

I recommend cleaning the cables and terminals with a torch and some flux. Remove the battery before using a torch of any kind. Flux will eat any corrosion present and leave a nice clean surface. Also make sure the actual terminals themselves are clean, on the post side as well. A cleaner can be had for 5 bucks or less.

And, btw, the lead terminals like this, they suck. Like seriously, ditch these.


These are basically budget terminals. I'd recommend seeking brass versions. Brass versions are a lot better. Like this.



And, one last thing. Stay away from battery terminal protection spray. Those have an insulating quality to them, and they make everything an absolute mess.

 

What you are describing is a bad battery to vehicle connection, the high AMP/Heat demand for starting is what is causing the bad connection to fail.

Since you have cleaned or replaced the battery end of the cables then only other place the problem can be is at the other end of those cables or the cables themselves.

First step would be to disconnect battery cables, then follow each larger cable to where it attaches to the engine.
Remove it and clean cable end and place where it attaches, often starter motor and engine block/bellhousing.

If that doesn't solve the problem then one of the cables, or both, has corrosion inside, under the rubber insulation, you can use a razor to cut back insulation and look for the whitish discoloration of corrosion, but it can not be cleaned out, cable must replaced.

From your last jump start experience I would look at the negative cable first, but BOTH need to be checked

With electricity, positive and negative both must pass the same amps or it can't work, so if starter needs 100amps on positive cable then that 100 amps must flow back to battery on negative cable.
If negative cable is corroded and can only pass 10amps then that is all the amps the starter can get from the battery on the positive cable, 10 amps, so you get a "click" and no starter motor.
When that happens the corroded connector heats up fast and stops passing any amps so everything goes off

 

Thanks all!
I suspect it is something cable related. The pos side looks like crap (not my doing) but it's to short to fix it w/o replacing both wires, or splicing, which I think would be more problematic!

For now I re-did the neg side, cut back about an 1" on both wires, and used those cheap generic terminals pic'd above (already had them, don't recall seeing nice ones at the store), and could only cut the pos side back 1/2", which was already exposed to the air, so no nice clean copper showing. But so far it's started each time tested. I'm sure it won't fail until the worst time!

I'll just need to replace the cables one day; hopefully this will bandaid it until it's