My buddy is telling me my '60 F100 (292/Fordo) would have a ballast resistor somewhere in the ignition circuit. It's always been 12v. There's nothing on the firewall where they usually are. I don't think there is one. He says it needs one. Who's right?

Thanks.

 

If your 292 has the stock points ignition system it should have a ballast resistor. The engine will run fine without one but your point life will be reduced significantly. The purpose of a ballast resistor is to hold voltage across the points to 6 volts and thus extend point life. It is wired so as to allow 12 volts across the points at start up but 6 volts afterward. If you are running an aftermarket ignition system check the manufacturer's instructions to see if you need one. Some systems do but most don't...

 

Should use a resistance wire going to coil instead of a ballast on a 1960.

 

How about using a coil with a built in resistor.

 

The resistance wire accomplishes the same end. I've never used a coil with a built in resistor so I'm not sure about that...

 

You can go either way. Resistor built into the coil or an external resistor - so you are both right. Mr. Tight Wad Ford usually had external resistors installed so if it went out you didn't have to replace the whole coil. If you had one installed it would be inline with the wire running from your ignition switch to the coil (the one providing ignition power).

They were often mounted on the fire wall, I have seen brackets for them bolted to the valve cover, or on top of the coil itself. It would be white (originally) porcelien about 2 inches long and 1/2"x1/2" square on the end with two tabs for connections sticking up on the ends. Sorry, I don't have a pic.

 

I bought the coil with built in resistor and seems to be working fine in my 292.

Ignition Coil DR180

 

1960 ford trucks came from the factory with a resistor wire! Check your volts at the coil with the truck running.

 

Well, we put a different engine in there and were wondering why it wouldn't start. We were 96% sure the distributor was toast but my buddy thought it might have some kind of resistor still hooked up that was limiting the voltage. It was probably that resistor wire mentioned above and it's probably still on the old engine. Thanks.

 

All the resistor does is reduce voltage to prevent points burn out. If you don't have one the truck should still start - UNLESS, you have an external resistor that has broken. Then the power circuit to the coil has been interupted.

 

As GreatNorthWoods said, the points/condenser/coil are actually designed to run on approximately 6 volts.

When you start the engine, the starter motor draws a whopping amount of current - as much as 200 to 300 amps for a short period. Your 12 V battery has internal resistance that causes its voltage to drop significantly when the starter motor is cranking the engine and drawing all that current. On my 1956 272 (essentially the same as your 292), I measured a battery voltage of about 8 V on a summer day when the starter was cranking the engine. On a winter day, it drops to around 5.5 V on my truck.

This would be a big problem if your points/condenser/coil needed 12 V to produce a good spark - you'd never get it to start on a winter day. Some clever guy or gal back in the day figured out that they should route the system voltage directly to the ignition when the starter was engaged. When the starter was not engaged, they routed the ignition system power through a ballast resistor that dropped the voltage at the coil to around 6 V. With this setup, they got a hot spark both when the starter was engaged and when it was not. The starter solenoid does the trick of switching the ignition supply from "direct to battery" to "ballast resistor" mode.

I've been AWOL from the forum for six or seven years due to a health problem so I don't really know all the folks here as I used to. Julie and others are clearly knowledgable with respect to the electrical systems for these trucks. If you want a wiring diagram that shows the ignition power circuit, they would be excellent sources. I think I have one on Earl's World at this link.

http://www.clubfte.com/users/earl/Re...rial.html#1956

One interesting result of the ignition system having a dual mode for power is that it is possible to have a good spark when cranking the engine, and no spark when you shut off the starter motor. The opposite is also true - it is possible to have no spark when cranking and a good spark when not cranking. I actually started my 1970 F-100 beater truck using the old bump-start method when I had no spark with the starter running and didn't have time to fix it immediately.

Your truck probably uses a special wire between the ignition switch and the coil to act as the ballast resistor. On the older trucks, a separate ceramic power resistor is used as folks have mentioned. In the photo below, the resistor is the white block held by the black bracket.

 

Dodge also used them into the 80's we had an 84 dodge truck that had 1 needed to carry a spare lol Julie

 

Good to have you back George Julie

 

Tee hee George is back, we have multiple Julies! It must be the Holidays

Merry Christmas everyone!

 

Hi guys I need some help. I tried to start my just rebuilt 272 from my f100 . the problem is I do not have spark coming from center of ignition coil I don't know if connection is wrong can someone Tell how to run the wires to get it work. I tested coil today in friend car and it worked I also have brand new coil and same thing. Made engine crank but nothing coming from coil thanks for your help.