Hi All, I'm having a issue with the wire to the horn relay from the battery. It is basicaly over heating and melting also the small wire from the possitive post to the terminal block is also getting very hot.Any body know what may cause this to happen?

Thanks

My guess would be an electrical short someplace.

Yes, high electical current (short) flowing through a wire that is sized too small for the amps its carrying will cause this. Our cars usually have good sized wires, so you are flowing a LOT of current to get the wire so hot it melts. You need to track down why so much current is flowing through these wires "before the fire" as someone else on this site has wisely said before. You could go through and check your fuses. Make sure a P.O. hasn't put tinfoil over a fuse or something dumb like that. It likely isn't a fused source doing it as the fuse would blow. Check other systems that don't go through the fuse block. You could unhook stuff one wire at a time at the horn relay bus and see if you can track it down.

I have determinde that it only is happening when the starter is being cranked. But still don't know why.

Ok that is something to work with. I am one the idiots on this site that will TRY to help you with only limited info ;-) (Nothing aimed at you Bobdog) Is the starter R terminal hooked up to a wire going to the coil? You could unhook the main heavy cable from the battery that attatches to the big lug on the starter, MAKE SURE IT WONT HIT ANYTHING METAL ON THE CAR. Sorry, dont want to hear stories of sparks flying. After its unhooked try to crank the starter (it wont of course) and see if the problem still happens. That may rule out a short in the starting circuit, or if it still happens you need to look elsewhere.

Good luck and let us know how it goes.

I had something like this happen to me after I had the car stored one summer. When to start the car and then wondered why it looked like the headlights were on. Then i realized they weren't. The wire from the battery to the horn relay was on fire. The car was off, w/o the ignition on, but the wire kept burning.and shorted the battery. Hydrogen was flaring off the battery. I freaked out and just ripped the battery cable off. Turns out it was a bad horn relay. I got a new relay, a new fire extinguisher, and some new underoos.

Hopefully it's something simple.

It it a honda or toyota?

Then again, it could be a 69 firebird. I don't want to apply what I know for fact in one case to what would be a best guess on a 7 or 8 becauese I don't have a clue how they work.

If it's a 9, the breaker points in relay are fried or frozen. Open it up take a look, and if you have even the slightest mechanical aptitude, it will be obvious whether or not the points are causing the problem.

Bobdog, what year is your car?
Is the heavy cable from the battery to the starter overheating as well?
Are any wires down stream from your horn relay getting hot or just the ones from the battery to the relay?
On a 68 the power wire from the terminal block goes to a junction and then to the relay, the junction is just four wires welded together in a splice and wrapped in the harness near the horn relay. The wires are red from the terminal block, red from the alternator, black fusible link then orange to the voltage regulator, and red to the horn relay. The red wire from the splice connects to the terminal on the relay marked BAT and that terminal is a one piece connection for the terminal that has a black fusible link and then a red wire which is the power up wire for the rest of the car, those two wires are always hot. A problem with any of those could cause the overheating. The horn relay also has a hot black and pink wire that goes to the key and the drivers door jam switch and is the key reminder circuit. The other hot black wire off the relay goes to the horn switch in the wheel. The wires to the horns are only hot when the horn switch is grounded and the relay closes.

I'm sorry I shouldn't have used the term hot or always hot, I meant they are connected to battery power and always have 'juice'.

Al

it's a 67 and I will look into all the info you have sent and hopfully figure it out. thanks to all.

Well I found that problem.it was a faulty ignition switch. Now i have a new one.The resistor wire to the coil is getting so hot you cannot touch it. But the wire reding is only 7.2 volts. Any guesses as to what may make it so hot?

Thanks Bob B.

Kinda subjective but they do get 'really' hot. Also, if you where not clear on their purpose, there job is to drop the voltage.

is there anything else feeding off that wire / terminal on the coil? In order for a wire with that low of resistance to get that hot it would need a lot of current going through it!