So when I start the truck up and run it the wire behind the fuse panel going to the horn circuit is getting way too hot for my liking. I have a standard gm truck alt with internal reg. My harness is an EZ wire and they are on east coast time so I cant call em today.Its actually getting hot enough to smell so I know I have a problem,I do not have a horn at all and none of that wiring is even there any more.The alt is actually a 67 amp unit and I have no accessorys other than raidio and electric fan. I have rewired the fan correctly with the painless relay kit and even with the fan off this still occurs.I have removed every thing from the system minus ignition and charging so Iam leaning towards the overcharging aspect. Could the problem lie in how I wired the alt? All I did was hook up the batt wire to the term and plugged in the little plug I had at the top and jumped that wire to the batt term as well. The other wire is cut off.I know Im missing something so any help is appreciated.Any ideas?The diagrams I have looked at on the net and through searching here are vauge so Iam definitly missing something.
You need to put a voltmeter on the battery when the engine is running, I don't think the problem is overcharging. Sounds like a short somewhere in that circuit.
I just did A DC amp probe and with fan on and lights it charges at 14.5 volts at 39 amps. EDIT Looking through the different areas on the fuse panel I get different readings,14.1 at the horn circuit and 13 everywhere else.At the batt its 13 as well.
You mention that the wire that is getting hot is going to the horn circuit and you have no horn.Where is the wire going?
It is jumping from one side of the horn circuit fuse to the next row on the back side of the fuse panel.Part of the distribution of the fuse block.The horn relay wiring and that circuit were cut out of the system after the fuse panel.(at the back of it) with or without the fuse in the terminals I get the same thing.
I found some interesting stuff at www.madelectrical.com alot of good info.I do not have the diode wired into my alt maybe thats the prob?I have no run on issues and have never noticed this issue in the last 8 years.Wierd.And billetproof is coming quick!
More info needed on the wire that gets hot: Is that wire feeding the "key on" circuit of the fuse panel?? What does "next row" mean? What I am getting at, is that if the wire that gets too hot is actually feeding the ignition circuit and an HEI?, the wire could be too small to handle the load. The HEI if you run one, uses more amps. I just wonder if you made some sort of mod that changed how the fuse panel gets it's power from the "key on"? One other bit; if there is a loose rivet or loose terminal connection on the circuit or fuse panel, that will also cause heat. It would normally heat the loose terminal or rivet though.
Sounds like you have a short somewhere. You say it's the horn circuit? Is there a fuse in that circuit? Is that a constant hot circuit? Most horn circuits are. The first thing I would do is to check the entire horn circuit for an obvious short. Chances are, that if it is a constant hot circuit, and you leave it sit, it will kill the battery. If you can't find anything obvious, disconnect the positive cable from the battery. Connect a test light in series with the pos cable so that one lead from the test light goes to the pos terminal of the battery and the other to the pos cable. If the light comes on, you have something drawing current. If the light is on, either set it somewhere that you can see it from the fuse block, or get a helper. One at a time pull each fuse in the block and push it back in. When the light goes off, you've found the culpret that's drawing the power, and you've probably found the circuit that you need to look closer at. If the light is off, then chances are, that it's probably not the horn circuit that's faulty. Now, re-connect the battery cable and turn the key on, but not the engine. Does the wire get hot with the engine off? If it does, it's definitely not your alternator, but probably some higher amperage circuit that has somehow shorted to your horn circuit. Pull "keyed hot" fuses one at a time and leave them out long enough to see if the wire cools down. If it does, the circuit you pulled the fuse from would be the one I checked first. If you still get nothing, you'll have to really dig into it.
If it was a short, the fuse would pop. It's more likely too much load for the wire size, yet not enough to overload the fuse. What's that wire feeding?
If the wire still gets hot with the fuse out then the load is on the supply B+ side if the fuse. With the fuse out use a volt meter and see which contact is hot.In the back side of that terminal you will probably see more than one wire spliced in. Sounds like there might be some other component on that wire that is drawing high amperage causing the wire to get hot. Something wired wrong? Hard to diagnose with out seeing a schematic
This is what I found,I pulled the fuse panel away from the fire wall and the alt power wire feeds this side of the fuse block.when I say row I mean the metal Buss? not sure if thats the correct term I will try and do a pic in a minute,but that metal bar has a 12 guage jumper witch takes power across to the next metal bar.Im guessing the wir is too small? its the only one that heats up. Thanks guys for all the replys bear with me as electrical is not my area. goin out to take a pic.....
A no1 wire from motor too frame and about 12" long and batt to frame and another small one on the firewall behind the motor
How big is the wire that connects the alternator output to the fuse block? If it's any smaller than 10 gage (bigger number is smaller wire) then you need to put in a bigger wire. How old is the battery? If it's tired, then the alternator will have to work hard to keep it charged up, and that might be why it's charging at such a high current.
That jumper feeds the row where the main power comes into the block.Could I just move the alt wire that row?Or am bandaiding the issue.
That wire coming from the alt is 12 gauge too .Small Im guessing. The battery is A gell cell excide few years old but holds a charge well and load tests good too.
I'd consider running a new #10 (or #8) wire from the alternator output, straight to the battery positive terminal. or to the terminal on the starter solenoid where the positive battery cable connects.
Yeah thats a good Idea. Im gonna run 10ga from the bat term to the pos starter term 1st leaving the existing 12ga and see what happens.Would that work? I thought I saw it that way in one of the diagrams I looked at earlier.Damn wifes home so I gotta cook dinner too. Thanks guys I will do that and check back in a bit.
Ok so I made a new jumper for the fuse block out of 10ga. after looking really close at the back of the fuse block I could see where I had gotten it wet somehow. Probably when I cleaned the engine and the chemicals corroded the wire.Not only is it small but now its corroded.Done. pulled a temp for tonight from the alt to the panel as well out of 10ga. No more over heating wire. So tommorow morning bright and early I will go ahead and cut out the 12ga completely and solder the new jumper in place.Thanks to evryone who replied and helped me out. You guys rule. On another thought though,Why would EZ wire put a 12ga wire there? Seems that if all their kits are built this way more people will have issues.I know for a fact that the 4 other kits I have helped with have the same size wire for that circuit.Im hoping the corrosion issue (my fault) just stressed the rest of the circuit causing the issue and others dont have this problem.I have to say I really like the EZ wire kit as a whole but I think I will plan this modification in the future ones I dh and Squirrel I would say the battery is about 5 yrs old.Thanks again.
I'm not sure why they would put a 12 gage wire in that circuit when it needs an 8 or minimum 10 as Squirrel said previously. If you pop the hood on any American full size car From the mid 50's on you will find the heavier wires on the main power feeds. The 12 gage wire in that spot got hot simply because it was too small to carry the volume of current that your systems demanded. It isn't how much power that the alternator is putting out that caused the problem but the amount of current that the undersized wire was asked to carry to the ignition and accessories.
Yeah I cant believe I wasent even looking that direction before I started this thread. But again thanks for helping everyone. Sometimes you just get so fogged up you lose sight of what you are doing. So heres what I did this morning, Couldnt get a no.8 wire in time for me to go to work today and get it done so here is what I did, 1. Ran 2 10ga. wires from the alt to the fuse panel 2. Made 2 10ga. jumpers 3. Soldered everything back into the fuse panel like stock on the spare terminals. 4. Drank more coffee,then test ran. As of now when running with every accessory on the amp draws are split between the two wires and jumpers and they dont even get warm to the touch at all. Im stoked!!!!!!! What gave me the idea was some of the compressors that I install the motor leads are done this way so it is easier to work on.Also less fatigue on the wires.Off to work now and when I get home its load up the Ice chest and off to Billetproof in the morn!!!!!!!!!!!!!!!!!!!!!!!!!
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