Re: Seeking Advice for "New Owner Go Over Checklist" for 1939 120 1701 4 Door Sedan

Posted by David Grubbs On 2013/7/28 17:17:24

Randy, I just finished rewiring my 39 120. The task was somewhat overwhelming, but as long as you have a friend to assist you, it's not too bad. You will need someone to push wires thru from the top while you're under the car, etc etc. My suggestion is to not remove the wires until you are ready to start installing the new ones. That way you will know how and where to route them. One note of caution - the 39 used headlights with separate lenses, reflectors and bulbs whereas the 40 used sealed beams. If you car has been converted to sealed beams, the 39 wiring diagram isn't going to work. If you are lucky, the wiring diagram consists of multiple sheets, showing each section, with the colors indicated. If you still have the manufacturer info, you should be able to get copies of them. If you don't I may be able to help by copying the ones that came with my harness from Potomac Packards. Look at the electrical diagrams on this website, and compare the light switch wiring on a 40 or 41 to the 39. It should show you how the sealed beams are to be wired.

Also, dollar to a donut, the brake light switch is sticking. It's located on the master cylinder, which is under the car. Disconnect it and take it to NAPA and get a replacement. I found that if you get some of the tire dollies (from Harbor Freight for cheap ones; Eastwood or similar for good ones), it is easy to crawl under the car without having to use jackstands. Also, you can shove the car around to make room in the garage when you're not working on it. If you do use jackstands, I would suggest using more than four, and use the four legged kind, not the pretty ones with one leg. A 120 landing on your chest can ruin your whole day...