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No Power

D

Denvergrows

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So I bought a 1986 K5 about 2 weeks ago and have had quite a few problems already. I didn't pay a whole lot for it and I knew I would have to work on it(and wanted to) and so far everything I have been able to fix. However, last night I went to start it and it wouldn't start. On about the 3rd time trying, when I let off the key, it continued to try to crank on its own. i pulled the key out and it continued to try for about 10 seconds. finally it stopped and I noticed smoke coming from under the hood. I popped it and looked just in time to see the ground wire from the alternator to frame light on fire. literally for about 15 seconds it had big flames. I grabbed a fire extinguisher and went to put it out but it was already out. Just smoldering. i let it cool off and pulled the wire off and ran a new one. Tried to start it and nothing. No buzz when the key is in and door open. No headlights. No door locks. No anything. AT ALL. I thought computer but I don't think it has one. Behind the glove box is a spark control module but not the ecu. Is this normal? Can anyone help?
 
Yep, quite normal. K5s catch fire about once a month on average...........

Seriously, sounds like you had a perfect storm of problems all at once.

Its not normal for there to be a ground wire from the alternator to the frame. Sure it was not the power wire?
If it was a ground, then the PO was trying to fix a ground problem the wrong way.

For the starter to keep cranking, either the purple wire going to the solenoid had power to it continuously due to an ignition switch problem, or a short somewhere else, or the contacts in the starter solenoid welded.

That is usually caused by low voltage causing the starter to draw too much current, or low voltage to the solenoid from the purple wire causing it to pull in too weakly.

As for no power now, you need to find the main ground wire from the negative terminal of the battery and make sure its hooked up.
Also, the red wires from the starter solenoid may have melted inside the insulation.

Check the heavy ground wire from the battery first, and try to determine what wire that is that burned up.
Post back what you find.
 
Since you fried some wires already, your fusible links are probably gone as well. Look on the fire wall above and to the left of your master cylinder. There should be a junction block there with the fusible links coming out of it. One or all of them are probably melted.:doah: At least thats where mine went when I had a bad short and then nothing worked in the cab.:thumb:

Z
 
OK so here is where I am at; I followed the wires from the starter to the back side of the fuse panel and there are no fusible links. I know it sounds stupid and crazy but the PO wired this thing up all kinds of crazy. But I got pictures. A few good ones to show the wires going from one side to the other. But I can't post them until I have 5 posts under my belt. So any new advice before seeing pictures?
 
If its been hacked and burnt up that bad, it may be easier to just pull a harness from a yard. Then you can atleast go through it before you install it, checking for shorts and bad connections. Then you can put some looming on it and install it in your truck.
 
Don't want to seem insulting, but do you know what a fusible link looks like?
Only reason I ask, is because lots of folks don't.

All a fusible link is, is a smaller than normal piece of wire with some flameproof insulation.
Its designed to melt and break the circuit before bad things happen. Lots of time they melt inside the insulation and show little or no sign.
The simplest way to find the problem is with a meter, but if you grab the wire on each end and pull, the bad part will stretch since there is no wire left inside.
 
I'm not sensitive. I'd rather be insulted and get my blazer running again thanks to someone helping me. I googled fusible link and looked at some pictures. That's the extent of the knowledge I have on them though. But I traced the wires from the starter to the back of the fuse box and I only saw one place where it might be what you describe. It is right off the starter. a red wire come off it, goes into a black shroud of some kind and 2 red wire come out the other side. I think its just some kind of connection. But I am wrong frequently. I can't wait to show a few pics. I bet you guys will know exactly what is going on then.
Also I have been looking at painless 10106 engine wiring harness. A buddy made a good point. I can pull one out of a yard but then I'm putting 20-25 year old wires back in the vehicle and it might be better to pay $150 and run all new wires. Any thoughts on this?
 
Fusible links are a good idea, but they will fool you. Modern cars are starting to come with high current fuses, and a lot of the people here have converted to them.

As for an aftermarket wire harness, they have several advantages, but they do require some wiring knowledge, especially the universal types.

Painless makes some that are more specific to the truck than that one. Check out 10205 for instance.

There are lots of folks here who have already done it, so someone should chime in with better answers.
Lots of folks who are doing major mods use a universal one and just wire up the minimum amount of wires.
In your case, I think the more standard one would be best.

If you have a meter, I can try to talk you through finding the problem you have now.
 
You don't have any links in the harness on the firewall?

Post #8 in this thread has a good shot of where they should be. Thats the junction block where mine fried when I had problems.

Z
 
Wow ok I have that. See I was wrong. But now I know. But I feel I need to post some pics so here is my 5th post pics in next.
 
So here is what I see around that area.
1. black "fat wire" one red going into one side 2 out of the other. (same thing that is comming right off the starter.
8448588208_45854d06e3_m.jpg

2. Some yellow wire connections between that bracket and the black thing.
8448588332_1e4cb4d5eb_m.jpg

Also the black thing is marked 16. Is that the fusible link?
 
OK, I'm more used to Fords, but most of the fusible links have a plastic or rubber "flag" or marker like that black thing.
The "16" is probably the size of the wire in the fuse link.
In other words, the regular size wire for that circuit is maybe 12 gauge, and the fusible link is a short piece of 16 gauge.
The black part is not the link, its attached to the link, which is the wire its self.

Grab the wire and try to stretch sections of it. If any of them stretch, then you have found the problem.
 
Not sure if you can see a pic without full membership, but if so, here is a pic of the schematic of that part you are looking at.

If you can't see it, it shows two fusible links tied together right at the starter, and both are red.

81-87_V8_engine.jpg
 
Just a guess, the fusible links are the two red wires coming out of that black thing.
 
ok none of the wires stretched. Would the fusible link cause the whole vehicle to lose all power? I'm kind of at a loss. I know a good bit about motors but not electrical. Anyone is the Denver area willing to come take a look at it?
 
Yep, all the power for the vehicle comes through those links.
Well, the starter power doesn't of course, but the power to fire the starter solenoid does, so the starter won't work either.

If you have a meter, measure the battery voltage first. Always start at the beginning, and never assume anything.
Then if its 12.5 at least, turn on the headlights, and measure from the positive battery post to the connection on the firewall.
You should read almost 0 volts.
If so, then measure from the negative post to the body of the truck, and from the negative post to the engine block.

If you get a voltage reading when measuring either of those, you have a bad connection between the two meter leads.
 
I burned up that link, too. It caused complete power loss- no lights, starter wouldn't turn, etc. Complete loss of power.

I'm trying to remember where the link was, I'm sitting at work so I can't bust out my service manual. IIRC, the link was between the black piece and the terminal (shown in second picture). Check all of the wires coming out of that terminal. Plus, you can obviously tell that the yellow crimp connector is not factory, which tells me that maybe this happened before and was repair by the previous owner. Look at the wire between that crimp connector and the black rubber piece- in the pics it looks like a different color than the rest- I think that's your fusible link. Fusible links are supposed to be a certain gauge and a certain length, if they're cut short they may not function properly (not sure if that would make them burn out too high or too low). If that repair from the crimp to the terminal is normal wire and is supposed to be a fusible link, it all needs replaced. Also, I think there's a fusible link closer to the starter, too, it may have burned out as well. I posted a question about the same thing 6 months ago or so, I'll see if I can find that topic for you.

Last thing- pull all that electrical tape off and inspect that wire where it connects to the terminal. All that tape could be hiding a problem under there, too.
 
Just got back from autozone. Got a volt meter(trying to figure out how it works.) and 2 fusible links. All they had were 14 ga and mine are 16(?) but I can't see a problem with using a 14 instead of 16. Especially for the purpose of just figuring out if that is the problem. I think either way I am going to try to rerun a lot of this electrical. Painless wiring seems the best solution for a novice on the matter like myself. But for now I just need to get it up and running.
 
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