Took Battery out to charge. Put battery back in. Hooked up backwards... Doh! .... Positive to negative.... Quickly noticed problem. Put back the right way and immediately wire from solenoid, where positive battery terminal connects to wire that terminates to 2 other wires (One goes to ignition switch and the other goes to some place I am not sure) starts to smoke and melt sheathing. What the heck did this dummy do?

FYI... The 3rd beer is my limit when it comes to doing dumb stuff prevention!

 

You probably smoked the fusible link and it should have protected most everything.

 

Pay attention to how/if it charges. Sometimes alternators get smoked by this over a few days or so.

 

Can you see the yellow wire between the red and green connectors? That now get's hot and melts when the battery is hooked up correctly.

 

Can you point out where that might be on the pic I just posted?

 

I can't even connect the battery the correct way without the yellow wire (just posted pic) heating up and melting.

 

The yellow wire is your fusible link it will need replaced. if it sizzles when hooked up correctly it could mean 2 things, something is fried and creating a heavy draw, or maybe it's so close to burnt off it can't handle any load.

The alternator would be the first place I'd look if you do have a short.

 

Might help to diagnose if knew what the two other wires go to from under the green twist on cap.

 

From the pics, you have some hacked up wiring already and the fusible link may no longer exist. The use of household wiring marrettes and crimped connectors is never a good sign. I suspect that the yellow wire was originally your fusible link.

If you still have a short circuit, that points to a damaged alternator--specifically blown diodes in the alternator Connecting a battery backwards causes full current from the battery to flow backwards through the alternator diode bridge which is polarity sensitive. They do not "get smoked over a few days or so" as another poster mentioned--generally the damage happens immediately if the fusible link doesn't do it's job.

Do you have a garden variety ohmmeter? Disconnect the heavy wire from the alternator stator terminal and measure from the stator terminal to the body of the alternator (ground). Reverse the the leads of the ohmmeter and repeat the test. If you get a dead short both ways then the alternator diode bridge is blown. The alternator can be disassembled to replace the bridge, if you can find someone who sells diode bridges these days. You need to have decent soldering skills to replace the diode bridge. I prefer repairing alternators instead of getting an exchange unit from a parts store--less troubles than iffy exchange units. I do electrical control system work for a living so it's kind of in my wheelhouse.

 

There isn't a lot about this trucks electrical that isn't "hacked". I inherited it this way and I am having to relearn how to work on an old vehicle. I do have a Southwire 10031S. So, if there is 0 resistance, or close to it when I measure, the alternator is toast or at least the diode bridge?

 

I'll investigate. The green one goes under the dash and connects to the ignition, fuse box and the radio, among other things. Not sure about the black one.

 

The diode "bridge" is an arrangement of 6 individual diodes. A diode is like a foot valve in a water system. Just like a foot valve, a diode only lets electricity flow in one direction. When diodes fail they do one of two things, go "open circuit" or "short circuit". In your case, with the battery connections reversed the battery current (amps) flowing through the diodes may have exceeded the rating of the diodes which usually causes them to become shorted (0 ohms resistance). So yes, if you measure 0 resistance when measured in both directions (or very low resistance then the diode bridge is damaged. In one direction the measurement should be infinite resistance (think foot valve blocking flow) and low resistance in the other direction (foot valve allowing flow).

 

My cousin need a jump start once and a good Samaritan came to the rescue. She said there was a huge spark show under the hood. She couldn't believe a man didn't know how to hook up cables. Had to replace entire harness from alt to solenoid and regulator. Of course alt and regulator. The only thing inside your truck that would be polarity sensitive would be the radio.

 

How about that cable that runs from the solenoid to the starter missing the insulation!
Then he has them bolt on battery cable clamps!

Before you go hooking the battery back up again replace all the battery cables before you burn aomething else up.
Dave ----

 

I had an issue once when my starter shorted out on my header, and fried a wire all the way to my ignition. Just to be safe I would make sure nothing is fried in that wire cluster going to your ignition. I had to do some serious rewiring, and heat shrink wrapping of some wires.