Coil resistance wire getting hot

[tjratt]

The coil resistance wire that splits into 2 yellow wires to the coil and starter gets hot when the switch is in the on position and engine not running. If I disconnect the yellow wire from the coil it doe not get hot. Would this be something wrong with the coil?

Thanks

[RichardJ]

That,,,,, is the exact reason you should not be sitting there listening to the radio with the key ON and the engine not running.

['68OrangeSunshine]

That wire is doing its job right if it's getting hot. It is the [White/Purple/Orange 20] resistance wire that is the power supply to the (+) coil. In a point system, it's necessary to drop the voltage from 12 VDC to 9-7 VDC after first ignition so the points don't burn up.
If you're not using points anymore, you need to bypass this wire and feed the HEI coil from a full power 12 VDC source.

[In The Ten Ring]

My truck's radio will play even with the key out and the ignition turned to "off."

Is that normal?

[tjratt]

Thanks for the info 68OrangeSunshine. I will fire up the truck.
RichardJ I wasn't listening to the radio, I am putting the motor back in and just checking things out before I try to start it.

[RichardJ]

>>RichardJ I wasn't listening to the radio,<<

Sorry, I didn't expect you would take it that literally.
You just can't leave the key ON for extended periods. If the engine has come to a stop with the points closed the ballast, the coil and the points can over heat. If you knew the points were OPEN when the engine stopped, it wouldn't make a difference. Pertronix modules can also burn out with the key left ON for long periods.

When the engine is running, the points are closed no more than 3 milliseconds at a time. Even less as rpm's increase.

[MagmaJct]

The primary winding in the ignition coil has a low resistance. If the ignition were to be left on with the points closed, considerable current will be drawn through the system. The ignition switch, the coil itself, and the points. Even at low engine speeds this can be a problem because at lower RPM, the points are closed for a longer duration, than say, highway driving.

The resistor wire increases the resistance of the circuit reducing the current. The additional wire that goes to your starter, doesn't technically "go to" your starter, but instead "comes from" your starter. The starter solenoid has an extra terminal that deliver power from the solenoid to the coil, bypassing the resistor wire altogether.

This gives the coil an extra "boost" of current to aid in starting. This has the added effect of compensating for lower available voltage during cranking. Because starting should only last a few seconds, the extra current doesn't present any danger to the system.

Enjoy!

Regards,
Mike

[FirstOwner69]

Originally Posted by In The Ten Ring

My truck's radio will play even with the key out and the ignition turned to "off."

Is that normal?

Nope. Should only play in the accessory and on positions.

['68OrangeSunshine]

Originally Posted by In The Ten Ring

My truck's radio will play even with the key out and the ignition turned to "off."

Is that normal?

Not what was normally done in production models with factory radio. The radio was usually set up in the key-on accessory mode. That keeps the radio from draining the battery if you shut the engine down and walk away.
'67s don't have an Accessory position on the switch. Some owners who wanted an aftermarket radio, and also wanted it to play when the truck was switched off, would wire the radio positive lead to the unswitched side of the fuse panel. It was their responsibility to remember not to drain the battery if seriously grooving-out with the engine off.

[alsriv2]

I have always heard of the "don't use the run" position with the engine off as I was growing up, but never got the down low on the why's. This is the first clear explanation I have seen.
This will help when I wire up my 396 this summer. I want to make sure everything is as it is supposed to be.

[In The Ten Ring]

Originally Posted by '68OrangeSunshine

Not what was normally done in production models with factory radio. The radio was usually set up in the key-on accessory mode. That keeps the radio from draining the battery if you shut the engine down and walk away.
'67s don't have an Accessory position on the switch. Some owners who wanted an aftermarket radio, and also wanted it to play when the truck was switched off, would wire the radio positive lead to the unswitched side of the fuse panel. It was their responsibility to remember not to drain the battery if seriously grooving-out with the engine off.

That's probably what it is then, my truck's previous owner (my dad) took the AM radio out and put in an AM/FM 8 track radio and he probably wired it up that way.

I can also turn on the interior lights by turning the light knob to a certain degree. I do not know if it came that way or if that's something else dad rigged up.

Very good safety info on this thread!