1952 DeSoto

[Harrymax]

I am having trouble starting my '52 DeSoto S-15 Custom 6 cylinder. There is no spark coming from the distributor. I put in a new battery, cables, points, rotor, condenser, plugs, wires, and voltage regulator. I'm a bit confused with the "Cir Breaker and resistor unit"wires.There's also a extra wire hanging off the generator that I don't know where it belongs. Any advice would surely be appreciated.Thank you

[Guest Rylujan]

I am having the sme issue with my 52 Desoto. I have very little or no spark. It cranks over and I have replaced all components as well. Please help. I think I have a wire issue. If someone can send me pix on how the engine is wired. Thank you.

[Guest rsd9699]

First and foremost you should have or get a shop manual. You have tossed money into the trash bin and still have the same problems.

The shop manual will provide the details for what you are asking and you will have saved a ton of money and time.

But since you have asked for help - pictures work better than guessing what you are describing.

I wounder why the forums don't ask you up front when a new thread is created - if you have supporting pictures to go along with the questions?

Ron

[NTX5467]

The wiring circuits on those cars should be the same as most any other pre-'55 Chrysler product car. Compared to more modern vehicles, simple and straight forward.

Go to Master Technician Service Conference - Chrysler's Training for Mechanics This will bring up a numeric list of Chrysler Master Tech Service Conference training materials. Scroll down to #036 "Ignition System Servicing" 1950 When you click on this course, it'll bring up a picture of the cover of the booklet, plus an index below that. Click on the item for p22. When that page comes up, go to the bottom of the page and click for the next page, p23. On p23 is a simplified electrical schematic of the ignition/battery system.

Continue scrolling down to #046 for V-8 Distributors, then on down to #067 Electrical Fundamentals (a more detailed electric schematic on p30) with more details in the diagnostic checks a few pages later.

I think that might be enough tech information for you to successfully troubleshoot the system.

I'm presuming that the original positive ground for your early-50s DeSotos is still operative?

Notice that the ignition switch in in the circuit going to the coil. In some of the "Help" comments for various no-start issues in another section of the "Repair" section of that website, the ignition switch was mentioned as possible causes of the "no spark" situation, in which case hot-wiring was a temporary recommendation. In another commentary, the radio interference capacitor was the problem, with an internal failure.

Hopefully, these documents can help you find your problem. Please keep us posted on your progress.

NTX5467

Edited September 14, 2011 by NTX5467 (see edit history)

[Rusty_OToole]

The circuit breaker and resistor unit is for the transmission controls. It draws its power from the coil wires.

First check if power is getting to the coil with the ignition turned on. If the coil is getting power take off the distributor cap and check the points. Clean them with a shot of contact cleaner spray and drag a strip of paper between them. See if you get a spark from the coil if you open and close the points with a screwdriver or wooden stick. To do this you pull the coil wire out of the distributor cap, hold it within 1/4" of the engine and open and close the points.

If the coil is not firing the next step is to find out why, if it is firing the next step is to see if the spark is getting to the spark plugs.