1938 Plymouth Ignition system problems

[mountainmax]

Hey people, IM new here (1st post) and wonder if someone could help me, I just got this vintage plymouth from my grandfather (who has passed on)and I want to et it running, it's been lying around not ran in 20 years, I have it cranking over fine now but am not getting any spark from the coil, looks like someone played with the wiring as there were fuses missing from some relays and different wires used, I have the shop manual with the car but it's not much help here, im not familiar with the points/condesnor system, I set the points gap but there is no capaciter inside the distributer, but looks like theyre is one on the outside, is this right: or is it missing completely? can get pics, anyonw with any help would be greatly appreciated.........Rob

[HarryJ]

Rob: The first thing I would do is to change the oil, plus putting a few squirts in each cylinder. Turn the engine over several times with the ignition off. When you get the engine cranked; quickly check the oil pressure,If you have none Stop the motor. Some older Plymouths had oil pumps that were not in the oil pan;but, were elevated on the side of the block, requiring priming.

[ply33]

HarryJ has some good suggestions regarding making sure you have lubrication so when you get the engine started you don't do too much damage to the engine.

Since you are not too familiar with point ignition would I be wrong in guessing that you don't know that the ignition switch on that car is separate from the starter switch?

I'd check with volt/ohm meter that you are getting power to the coil. On many pre-war Plymouths the coil is mounted through the firewall and the battery side of the coil is supplied through an armored cable from the ignition switch. This means that it is not easy to check the battery side of the coil for power. However as a first step, remove the low voltage wire from the coil to the distributor, turn on the ignition switch and verify voltage at the point where the low voltage distributor wire connects to the coil. You will not be able to use a test light for this as the internal resistance of the coil will be too great but a volt/ohm meter should tell you if you have power.

If that checks out, then I'd put the ohm meter on the distributor and verify that there are no opens or shorts to ground. I would turn the engine over (hand crank if you have it is great for this) and verify that the resistance is zero when the points are closed and infinite when the points are open. Quite often there is either a bad ground (always infinite resistance) between the plate carrying the points and the distributor body or a short (always zero resistance) if some metal is touching the case that shouldn't.

Generally the coil is a pretty reliable device, so I would not expect problems there. But I have had troubles with ignition switches and with distributor grounds. In both those places there are moving parts to wear and break.

Finally, you will probably get a better response to questions of this type on either the Plymouth Owners Club bulletin board:

http://www.plymouthbulletin.com/

or at the P15-D24 forum:

http://www.p15-d24.com/

[Mika Jaakkola]

Here's a link for 1939 Dodge Wiring Diagram. I guess it should be almost same as in '38 Plymouth ?!?!?

Print it, and check it out-

http://www.dc.turkuamk.fi/users/mjaakkol/images/1939wiringdiagram.jpg

[vpl1116]

My 38 desoto has what looks like a condensor under the dash that us wired to ignition switch on the same terminal as the wire that goes from ignition to ignition coil , something is robbing voltage to the coil. Could it be that Condensor ? I get 6 volts to the ignition switch but only about 3 volts at the coil terminal  which causes a no start. If I jump a wire direct from battery to coil and crank the engine. It will fire rifgt up.. but won't fire without that jumper.

[Bloo]

It could be, but if it is drawing enough current to do that I would expect something to be getting hot. That condenser, being effectively hooked to the "live" side of the coil and not the points side, has nothing to do with the ignition. It is just to reduce electrical noise, probably for an AM radio. You can disconnect it and see. It won't hurt anything.

 

I would be suspicious of the contacts in the ignition switch, and that is where I would look next if disconnecting the condenser doesn't do anything.

 

Edited March 21 by Bloo (see edit history)

[vpl1116]

Thanks. I'll disconnect it and see if that does it. Looks like it is an aftermarket ignition switch already so may be one of china's finest productions. Lol. So the ignition switch will be the next try.thanks again