In all fairness I probably shouldn't of expected a $350 truck to run in the rain, but anyway: went to start the truck today in the rain (was running and driving just fine yesterday) and it only turned over a handful of times before the battery died. Odd seeing as its a new battery. Went to jump start it and noticed a loose serpentine belt! Must not have been charging, easy fix. Tighten it up, and when I hooked up that jumper cables sparks everywhere. Alright, disconnect all the cables, dry off all the contacts and try it again in a different order, sparks everywhere. Long story short using a multimeter on continuity setting I get near perfect continuity between my battery positive and negative. Great. Followed the positive up around the radiator to a plug on top of the driver's front fender and unplugged it. No more continuity between battery posts. Dang, that woulda been easy. Next I checked two black 16ga fusible links one on an orange and one on a white wire. Both have continuity to ground. Anyone have any suggestions on where I should look? Is there a common weak spot in the early ranger's wiring I should check? Any help is much appreciated. Truck is an 84 standard cab that cam with a 2.0 and now has what is thought to be an 80 engine out of?. Lots of extra sensors and vacuum lines (coming from box on passenger fender). Anywhere I should specifically check? No fuses are blown so I can't imagine it's in the wipers/lighting/heating system anywhere. Thanks.

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When you said "using a multimeter on continuity setting I get near perfect continuity between my battery positive and negative" I about dirtied my pants! If you did what you said, you would have seen plenty of sparks and smoke!! How can I trust that you know what you're doing with a comment like that?? Good luck to you!!!

Uhh...no you wouldn't. I don't even know how many times my leads have been on the +&- before.

I wouldn't have hooked my $500 worth of meter & leads if that would happen. Maybe with the $5 harbor freight one you use? Don't know

"on continuity setting"??? That's checking ohms, not volts.

No...that setting is for continuity. If a circuit has continuity it means they're touching. Like testing a fuse. Good fuse has continuity... blown doesn't

Impedance is for OHMs

Impedance/ Ohms is just below the range and continuity is right of it

OP...that's a pretty old truck with apparently non stock this and that. I would start with a repair manual for stock. They have a ton of trouble shooting, plus you can possibly figure out what has been changed.

Good investment for $25

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No smoke/spark can from the multimeter, just from the jumpers, lots of spark/smoke came from those. I have a repair manual and it seems the wiring harness is about the same. The battery was putting out less than half a volt so I disconnected the battery and checked continuity from there. In hindsight I should've said that I checked the terminals. I do only have a $25 multi-meter because I was afraid I'd fry a nice one. I'm pretty good with electrical schematics, I'm just used to fluid power ones and the ones out of the manual are a bit different. Does anyone know where the first two fusible links are coming off the positive wire? Ones 14ga and ones 16. I figure the short has to be before those otherwise they would've blown, right?

P.S. I hate these rubber molded fusible links!

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Here's where I'm at.

No key
-no dome light fuse
-headlights turned off
-infinite ohms

No key
-door closed
-headlights off
~5ohms

No key
-door open
-headlights off
~1.4ohms

No key
-door open
-no dome light bulb
-Headlights off
~5ohms

Key turned to any position
~14 ohms

Key turned to any position
-headlights on
~.8 ohms

Any input would be greatly appreciated. I'm not exactly sure what's activated when the key is turned to accessory, I'd imagine just the radio and some light (when the door is open) right? Maybe it has something to do with the radio.

No change when the radio fuse is pulled.

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what does this mean.. whats touching .. electrons.. and what does Impedance is for OHMs mean?

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2011 XLT 4.0

Ohms is resistance.


After pulling the dash, headlight switch, fuse panel, and random parts of the wiring harness apart several times I just got pissed and threw the battery back in. It runs! Not sure what the problem was but it's not charging at the moment so I'm gonna get the alternator tested tomorrow. Luckily I have a boat battery I can bring with me for the day to get to and from school. Thanks for the help!

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Check your grounds. That's the single most common electrical issue in cars.

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2004 Ford Ranger, 4.0L, 5 Speed Manual
Leveled, 32/10.5/16 (Metric) BFG All-Terrains
Fab-Tech Light Bar w/ KC Daylighters
'06 Taillights, Clear Corners
Future Mods:
5.0 Swap (Handbuilding motor)
SAS or 6" IFS Lift

Continuity means that the two points being measures have the same voltage potential and also there is almost no resistance (because it is next to impossible to achieve zero resistance in a wire) between the two points. This can also be called a node.

Ohms is a measure of resistance, which is the opposition to the flow of current.

Look at the Ohms law:

V=RI
where voltage=resistance*current

Since this is an automotive DC system V is almost always 12V (except for voltage supplied to sensors which is 5 V).

The higher the resistance the less current and vise versa.

Now Impedance is a measure of resistance mostly used in AC circuits. It has a magnitude and phase angle. In DC circuits the angle is always 0 degrees so you only see magnitudes.

Because of the nature of coils (inductors) and capacitors, these elements have impedance.

When the elements have only DC current applied the capacitor acts as an open circuit and the inductor acts like a short circuit.

Thats just a bunch of information thrown out there. I could write about 20 pages worth covering more details that would confuse the hell out of you, but I hope that somewhat helps.

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Automotive Electronics Engineer
2000 XLT 2.5L A/T
Mods:
Explorer OHC
Explorer Autodim Mirrors w/ Autolamps
Explorer Sport White Face Gauges

And that's exactly how Littleman got his truck running again! Good job Littleman!

Pro tip #32: don't suck

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95 Ranger XLT 4x2 2.3 I4 5 speed 206,000 *dead*
96 Ranger XLT 4x4 4.0 V6 5 speed 173,000 *alive*
D35 front, 8.8 rear, 3.73 gears, limited slip rear diff