Packard Forum Index » Pre-War (1899-1942)

Hate to keep blowing up this forum, but I'm a lonely boy in Louisiana and everyone around me has Camaros, so, I need all the help I can get.

The old coil was getting very warm, so figured that might be part of the spitting and sputtering. If you're familiar with 1929 models, it was NOT the bizarre factory type coil with the ignition switch built into it, but rather, a coil they had jerry rigged into the original housing. Me, figuring a coil was a coil, I slapped in a 6V "no ballast resistor required" coil from the NAPA store, and the car ran fantastic with that - for about fifteen minutes.

Smelled that nasty something's hot electrical smell, shut her off, (thankfully in my driveway), got out to hit the battery kill switch, but, the fuse on the firewall had already blown. Coil and the ignition switch were hot as a firecracker.

So, simple question, did I use the wrong coil or likely install the switch incorrectly (I think they used a '30-'32 ignition switch rather than the weird-looking original). I suppose the basic question, do 1929 Packards use external resistor coils or internal resistor coils?

The coil I put in looks like the one at the bottom but says 6V and is numbered 1304. It was hot as a firecracker after about 15 minutes of running time.

Sorry to be a pest, but, Sophie teh Packard has been determined to drive me nuts in the last several weeks after being pretty darned reliable! Thanks!

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I think ballast resistors aren't necessary for a 6V system, but I might be mistaken. I have a Napa 6V coil in my 31 and it runs fine, no problems.

Assuming you have a positive ground car, the negative side of the coil (power) should connect to the ignition switch, and the positive side of the coil should connect to the distributor.

I can’t answer for a car this old but I can say that wiring it in reverse might make it have a bit less spark in the plugs than it should but I can’t imagine it making it overheat like that! I am curious to know too what happened.

For what it is worth, the 29 drawings do not show any external resistor. While the drawing does show the coil internals, it is hard to tell from the drawing if there might be a resistor inside the coil but typically 6v coils did not require or have one. On a modern universal 6v coil I would not recommend using a resistor because that might make the spark too weak to reliably jump the plug gap.

12v coils use some type resistance because most often the coils are designed to work at approx 8-9 volts so as not to overheat. Working at the constant lower voltage also allows circuitry to briefly provide a separate voltage to the coil directly from the battery to sort of counteract the voltage drop due to the heavy current required by the starter motor during cranking and provide a stronger spark.

As to the ignition switch, depending on type the modern designation for terminals would be BAT, IGN and ACC. BAT would be the supply in and IGN would go to the coil only while ACC would supply everything else. For the separate from coil stock Packard switch until 54, their usual designations were AM, GA and COIL. AM corresponds to BAT, GA to ACC, and COIL to IGN. If the switch has only a single on position both IGN and ACC terminals are active but in a switch with a right and left position, ACC will be active in both while IGN is only hot in the right side or the typical run position. If there is an accessory such as a fuel pump that is only wanted to be on when the engine was running that would also be powered from the IGN terminal.

Here is the wiring details from thje 1929 AEA drawing available at the PAC site.

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Thanks for that diagram! I think I'm gonna switch to the plainest black 6 volt coil I can find and pull the switch out this weekend for a good look. Based on that diagram she's wired correctly, so, maybe in my epic struggle to get the old coil out, I've got something loose on the back of the switch or it's grounding out across the back of the coil mount. Hopefully I didn't fry the poor thing and the fuse saved my ignition switch!

Thanks much!

As I recall, the only 6-volt coils which had a resistor were the 46-48 Fords and Mercurys (maybe Lincolns too). Ford may have used resistors on earlier or later 6-volt cars, but do not know. 12-volt coils do need a resistor, ether external or internal, to prevent overheating and damage.

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This is correct. Positive ground tends to shunt the norms sometimes. Fact, most coils don't care about voltage. Old GM cars had 2 wires in the harness before it got to the coil for low voltage run, high voltage start. Of course the Mopars we know and love had the ballast resistor but also 2 wires for 12V start, ballast run. Use that as you will, but it may have been wired backward and would really overheat the small windings rather quickly. Good luck, let us know.