coil resistor ?

[brian]

maybe im blind but I dont see any resistor mentioned in the master parts.
for 12 volt radio command car. fried some points last weekend. NAPA said we needed a resistor. whats the deal ?


BB

[Ray Edsall]

G,Day Brian . There was a resistor mounted on the LH kick board in some vehicles to drop 12 to 6 volt. I think that all vehicle that had 12 volt,s originally installed . would have had 12 volt lights 12 volt {Green tag}Regulator , 12 volt coil , and 12 volt starter , 12 volt Genny as standard . There probably was a time in in the field that 6volt vehicles were fitted with 12 volts to handle the radio installation . But keeping lights ,coil dissy , etc running on 6 volt,s .So these Vehicles would use the Resistor . You probably need a 12 volt coil, spark plugs , Points , If you are running 12V system in your truck . Give John at MWM or Yan,s at VPW a call . They should be able to set you right . Ray

[Ray Edsall]

G,Day again Brian . Another possible cause for fried points could be a the distributer condencer failing . Ray

[brian]

like i said its a full on 12V command car. we mounted an SCR-506 in it about 2 years ago.along with the "Full Size" battery. the dyno on the radio perty much needs the engine on to keep from sucking the battery dry. which puts the generator in high charge mode all the time.

I wunders if this could be hard on the coil.

BB

[brian]

this thing was a second hand restoration. that weve really had headaches with. from the fuel system, to sticky valves last winter. to having to rewire the BO lights like you said. im about ready to blow it in place.

[Kaegi]

I believe the 12 volt coil has an internal resistor. so no external ballast resistor should be needed. I would replace the condenser as well. try to find an NOS condenser as the modern ones are Chinese junk and fail frequently.
If the regulator is working correctly it should not be overloading the system even when running the draw of the radio. those extra amps should be getting sucked up by the battery and radio. might need to adjust the regulator. I had a WC57 and the reg stuck on max output and the lights were real bright! I pulled the cable of the battery when it was running with the lights on an all the lights in truck blew! the headlights were shingin like the sun there for a minute.

[Tony B]

Much as I like originality, I have to say, change to electronic ignition. The one I have, so far about ten years , is a British built one by Jolley Enginering. Makes for good starting and running. It fits entirley into the original distributor all you can see is one more fine wire. takes about ten minutes to fit.

[tankdriver]

I'm a old fart I know, but I grew up with points on my go karts as a kid, lawn mowers, tractors, and cars, and they worked fine.

How many planes, tanks, jeeps, trucks, motorcycles and race cars have run points over the years. It's a good reliable system.

The burning points is probably just a bad condenser.

[Tony B]

Me to. Ask a 'modern' mechanic to check points, the first thing is a clueless look follwed by 'Where do you plug the computer into them?' However, I'm all for making my life easy, and I have to say the new ignition does. Also with the better manufactuers not producing old ignition parts anymore new parts seem to have relaibility issues.

[tankdriver]

Me to. Ask a 'modern' mechanic to check points, the first thing is a clueless look follwed by 'Where do you plug the computer into them?' However, I'm all for making my life easy, and I have to say the new ignition does. Also with the better manufactuers not producing old ignition parts anymore new parts seem to have relaibility issues.

Worse that that, ask most anybody if they know how to read a vacuum gauge. They usually reply, "What's that"....

You can find out most anything with a vacuum gauge. I was a poor boy, and could not afford a timing light, but I could set my timing, and carbs with my 4 buck vacuum gauge....

[Ian Jamieson]

I don't believe the "old" coils had an resistor, ballast resistors & 9 volt coils didn't come into common usage until the very late 1960's.

I suspect your points burning out is more due to a poor condenser than any other reason.

If your concerned that your voltage regulator is not playing ball, you can check the voltage at the battery with a simple volt meter, across the battery terminals with the engine running at a high idle speed (say 1200 rpm). If the regulator is operating correctly the voltage will be around 14.5 volts. Anything higher indicates the regulator is set too high and this could be contributing to your problem.

ALso, avoid long periods with the ignition on, but the engine not running. ENgines generally stop (when turned off) on a compression stroke, it often happens that the point at which the engine stops will be right on the point that the ignition points begin to open. If this happens and the ignition is turned back on then its entirely possible that the current will arc acrss the points and burn the points.

Cheers

[brian]

so the latest in the coil saga-
some kid came touring through the barn and sure enough turned the key on.
we are all standing around an hour later, and POP poof nice little fire under the hood.

got it out perty quick. lucky we hadent gone home yet.

that deep well tractor battery is a bad boy.

BB

[Gordon_M]

Lucky you were still there.

I can see battery isolator in your future - may I recommend the one found on the dash of the Weasel? It works well and for extra security you can take the eared end off with a single screw and hide it somewhere.

[Kaegi]

was the coil form 1942? or was it from china? ;/)

[Andersun]

The 3/4 WCs have the output terminal of the coil aiming downwards. The reason why the Chinese coils (maybe the Mexican ones too) fail is because they leak! Once the insulating fluid get low enough, the coil heats up and quits working. If you reverse the mounting of the coil so that the output terminal is aiming upwards, you should get some more life out of it.