Mike38122

Wassup guys......I have a 1990 K1500 4WD 5.7.......The other day I was driving and my truck started losing power.....pulled over and it dies and wouldn't turn back on......had it towed back and still has somewhat electrical power....rolled up my windows.......the next day I installed new alternator and belt......battery was recharged and tested at autozone.....battery cables are only three weeks old.....new starter when alternator was put in......there is absolutely no electrical power what so ever even when I tried to jump it...nothing......Please help me lol

SWHouston

Mike,
You need to do a spot check on every point in the route of your Cables.
If you don't have a simple VOM (Volt-Ohm Meter) you can get a inexpensive one from Radio Shack or other Electronic Supply.

Set it on the 20 volt DC scale, touch the negative (black) lead to your Metal Frame or the Negative Battery Terminal, and start by touching the Positive (red) lead to your positive Battery Post.

You should get about 12-13 Volts, then to the battery Terminal it's self, then to where it connects to the Starter. You may at some point not get a reading, and you can address that item/cable/whatever when you locate it.

Mike38122

Thanks for the reply.....but The cable that runs to from the top of my starter(a purple wire)......to this plastic block on the drivers side engine bay.....it looked pretty sketchy Im hoping its just that......do you know if this truck has a main fuse??? and if so where its located

SWHouston

Mike,
I sure don't know much about your specific model, but...
If a Wire/Connection looks "sketchy", IMHO it gets fixed quick !
Even with some minor abrasions, moisture can enter the jacket
of Cables, or corrosion on a Terminal, and reduce their efficiency.

I did a quick search on "Chevrolet electrical diagrams" and found...
Chevrolet Wiring Diagrams | Automotive Wiring Diagrams and Electrical Diagrams
maybe something here can help.

Mike38122

Im Learning new stuff everyday man......but do you think just a little corrosion could cause FULL electrical shut down???

SWHouston

Mike,
Customarily no, it usually just reduces the "power/amps" that can be transferred, but will allow some voltage to be transmitted.
One of the most "sneaky" areas, can be the Battery Terminals. They can develop a corrosion (looks sorta black to me) between it and the Battery Post. Unless you literally "carve" it out, or use a round wire brush to clean the Terminal, it can present a problem. If any metal component in the circuit is not "bright" and clean, it gets that way before I give up.

Tips...
I bought a small Toothbrush like Wire Brush with Stainless Steel bristles. It's just perfect for doing threads on the Starter and other "in-line" items which have a stud type connector.
Also have a very worn out Circular Wire Brush which I can slip into the Nuts, and clean out their threads.
Any Wire/Cable which has a "bulge" or frayed insulation in any area, gets replaced.
You can "glob" some Bearing Grease on the Battery Terminals if you don't have covers which are in good condition.
DON'T forget about your Grounds, Battery and others which make the connections from the Motor/Frame/Components. They can cause a loss of operation just as easily as a Positive Conductor.

Running though high water is a way of life where I live, and the most likely contributor to corrosion like we're talking about.

Regular Preventative Maintenance, means you get home "regularly" !

BTW...
Have you done that "spot check" with a VOM or Test Lamp to see where exactly you're loosing power ?

Mike38122

found the problem the alternator wire was acting funny I checked it earlier and nothing.....right before I went to pack up I wiggled it some more and magically everything worked again lmao thanks for all you help

SWHouston

HA, Mike, you shouldn't be able to "wiggle" your Alternator !
You need to dig a little deeper, and find out just what's going on there,
or, you're going to be right back where you started !