Little help understanding

[natvet]

The history.. I wired up and ingition system to start the 40 after rebuild. I wired from +bat to rocker switch (thru fuse) Then from rocker to coil balist resistor and idle solenoid on carb. Turn over starter and it ran great until the points burned out.(( too much voltage I think). Coolerman said they would.
My question is when i wire the truck normally(when tube is back on) what will prevent this from happening again? Does the ignition switch cause a voltage drop enough to prevent frying the points or is the voltage regulator involved? Or am I missing something?

 

[grant5127]

The ballast resistor controls the voltage.....

Is it wired correctly?

 

[natvet]

Ballast resistor is wired as follows. 12v from batt to bottom side of resistor ....... top of resistor(with wire already on resistor) to + pole of coil. There is a wire from the dizzy to neg side of coil.

 

[grant5127]

I'd check the resistor for proper voltage drop.....

6~9 Volt

 

[natvet]

Will do. To be sure.... Hook batt to bottom side of resistor and measure voltage at top of resistor should read 6~9 volts.

 

[grant5127]

yep....

 

[natvet]

Measured batt voltage 12.47v... Hooked up ballast resistor w pos batt on bottom and measured volts on top pole ...12.47v... Reversed the poles(batt on top measured volts on bottom) and still measured 12.47. The resistor is 1wk old.
Suspect I need a new one**@***@!!!.

 

[natvet]

Has anyone measured the resistance across their ballast resistor. If so, what should it be?
thanks

 

[Coolerman]

Typical values are 2-4 ohms. Depends on the resistance of the coil you have. If the resistor is good, you should measure about 6V ACROSS the resistor. (Meter leads on each side of the resistor.) The resistor is in series with the coil, splitting the battery voltage between the coil and the resistor.