Re: 1941 Packard 110 - Rewiring and 12 Volt Conversion Questions

Posted by HH56 On 2014/4/23 21:03:30

I don't think you will find a standard list of part numbers or even what items to replace all listed in one place. Each conversion is different. Fifth Avenue Garage has a printed general guideline but it is not Packard specific. They also carry some resistors but others do too. 12v bulbs you can get at parts stores -- just take an old one to compare and make sure the base is the same as the old 6v version. For many of them you could download a 55-6 owners manual from the site and use the bulb chart to get a starting number to ask for to compare. Headlights just plug in so again, no problem finding new bulbs.

Some other items may have 12v replacements but others not. For example, some Packard heaters have a motor shape or circuit that will not adapt easily to todays motors so you will need a resistor. If you have an original R9 OD there are no 12v solenoids and the relay box -- even in 6v -- is almost extinct. To keep the OD operational you will have to supply a healthy 20 amp 6volts to the complete unit. Resistors are not a good idea on ODs because the current draw is so different depending on what is happening. If you are trying to keep an authentic look, doubt you will find an original looking horn in 12v either so another large resistor for the high current they need. Alternators, you are on your own. You will have to adapt and if your engine uses the 1" wide belt there is only one place I've heard that might be able to supply an alternator with the proper size wide pulley.

You might consider a dual voltage setup. Convert to 12v for the engine, lights, etc and wire accordingly but buy one of the 12 to 6v converters to run all the original accessories -- particularly the OD -- that have no easy replacement. There are some on ebay made specifically for the car conversion purpose and might even be cheaper than buying individual resistors. Gauges could go either way -- either off the 6v converter supply or get a Runtz reducer or resistor for the gas and oil gauge. IIRC, the temp is mechanical and ammeter won't care about the voltage but with the increased amp output from an alternator may have to be shunted or even bypassed.

For the most part, since you are going with a new loom it would be fairly easy to keep a few things separate. The Painless is an option several have used but if looks are important, the plastic wire in a 41 would be a dead giveaway. There are some companies like EZ2Wire that advertise "heavy duty" universal looms. Those generally have a larger wire size suitable for 6v in them.