1955 ford with a 302 engine

This morning I did some voltage testing on the ballast resistor. With the ignition switch to on, I get 11.9 volts on one end of the resistor and 5.7v.on the other end.This is the end that connects to the + side of the coil. With the engine running,I get 10.4v on the + side of the coil, not the 5.7v.
Is this too much? I think you mention that it should have about 8 or 9 volts.
The resistor measures 2 ohms.
There are only 2 wires coming off the ign.switch that would have any affect on the ignition system which are the yellow wire going to the starter solenoid and the one going to one side of the ballast resistor. The others I think would not have anything to do with the engine shutting down.I am thinking about replacing both of those wires.
I think 12 gauge wires would be fine.What do you think?
Thanks again.
 
If you’re doubling the voltage with the engine running, I’d be checking the running charge voltage at the battery. You shouldn’t be much over 14.5 volts there. If you’re running at 16-17 volts, you’ll cook the battery,and who knows what else.
 
10.4v on the + side of the coil with the engine running may be a bit high but isn't too bad. If you have another resistor that will lower the voltage to 8 ish, give it a try.
But not knowing what ignition parts you have or how the newer engine was wired into the older car makes long distance diagnosis pretty difficult.
Do you know how or if the wiring in the car has been replaced / updated from original?

There may be another other wire for the Ignition you have forgotten. There is usually a wire from the "I" terminal of the starter solenoid to the + side of the coil. It provides full voltage to the coil for a hotter spark only while the engine is cranking.

The large yellow wire between the Battery cable (+) terminal of the starter solenoid and the Ignition switch is for power *to* the Ign switch, not *from* the Ign switch. You shouldn't need to replace/repair it unless the connectors are corroded or loose, or it's been overheated.
The same with the wire from the C / IGN position of the ignition switch to the ballast resistor, the connector ends may be loose or corroded.

Spend a bit more time looking at the ignition portions of the oem wiring diagram I sent a link to.
Don't replace wiring just on the off chance it might help, you may make the problem worse, or more likely create new ones.
Work to find the cause of a problem first and go from there.
.
 

Attachments

  • Solenoid - 4 Terminal Wiring.jpg
    Solenoid - 4 Terminal Wiring.jpg
    178.5 KB · Views: 9
Last edited:
Thanks guys for all your help. Origionally,this 1955 was a 6 volt system.I converted it to 12v right after the overhaul.I changed everything that needed to be changed from a 6 to a 12v.I removed the generator and put in a alternator, new voltage regulator,new 12v starter solenoid,changed out all lights including the dash lamps.
I checked this morning and noticed that the I terminal on the starter solenoid is not being used at all,no wires connected to it. On one side of the solenoid (battery side),I have 3 connections.The cable coming off the + side of the battery,the yellow wire going over to the Batt.terminal on the ign.switch,and another wire going over to the alternator.
On the opposite side of the solenoid,there is one cable only and it goes over to the starter. There is one wire on the (S) terminal of the solenoid and it goes over to the (S) terminal on the switch.The (I) terminal is empty.
Its been running good this way for years. I picked up a new Ballast resistor this morning and will connect it in a little while.The one that is there is about 20 years old.
Since There is no wire from the I terminal of the solenoid to the + side of the coil,how does it get the 12v to the coil for start up and give it a better spark.
 
poolplayer1 said:
. . .
Since There is no wire from the I terminal of the solenoid to the + side of the coil,how does it get the 12v to the coil for start up and give it a better spark.
Click to expand...
It doesn't, but if the engine starts easily then the wire isn't really needed. IF the life of your points is acceptable.
IF the 'running' voltage to the coil with a new ballast resistor becomes lower you may need to add the "I" terminal wire to the coil for starting purposes.

This could fall into the 'If it ain't broke don't fix it' category.

OR... since the engine is shutting off after 10 or 15 minutes it may be possible the coil or condenser is running a bit hot from the very slightly higher voltage it's presently getting.
I'm just guessing here.
Like miker said, 'just shutting off' is usually electrical... sputtering then dying is usually fuel related.

.
 
Last edited:
Instead of using voltage as a guide to proper resistance, measure the resistance between the + and - terminals of the coil. Do this by first placing the multimeter on the lowest ohm setting and placing the tips of the leads together. Read the ohms, write it down. Now read between the coil terminals and subtract the ohms from the initial test. This is your coil's resistance. It is desirable to have about 3 to 3.5 total resistance. Use a ballast resistor of the proper ohms to make up the difference. You can buy coils of 3 to 4 ohms resistance and not have to use a ballast resistor, but then the "I" terminal on the solenoid becomes useless.
 
I went ahead and replaced the ballast resistor. The old one was mounted right on top of the coil. I mounted the new one on the firewall. After I did this,I removed the dist.cap and checked the voltage at the points and its right at 8.1 volts. This I think will be much better.The coil is new and the primary reads 1.8 ohms. The secondary reads almost 11K. ohms. I think the normal on the secondary is between 8k and 12k ohms.
Like I mentioned earlier today,I had replaced a lot of parts when converting to 12v.However,the wiring under the dash is still original.In the morning I'm going to drop the ignition switch down to check all the wiring to see if there are any loose or corroded connections at the switch. Oh, I almost forgot to mention that after I replaced the ballast resistor,I also replaced the points and condenser. What else can I check that would cause the engine to shut down after running for about 5 miles?
I can't understand why it will not shut down running here at my shop.This way I could troubleshoot the problem and hopefully fix the problem rather than get stranded in the middle of the road.Do you think another possibility might be a faulty distributer?
 
A characteristic of a ballast resistor is that they increase resistance as they heat up. This supposedly gives higher voltage starting, assuming the resistor has cooled off, and then reduces voltage to increase point life.
 
poolplayer1 said:
. . . I still think its vapor lock.The only thing I have not replaced is the carb. I might try a phenolic spacer on the carb. and see if that helps.
At least I have one problem solved.Thanks guys for all the tips and suggestions that you all gave me on the overheating problem.
If the fuel in the carb.is boiling and thus causing vapor lock,is it a fault within the carb. or too much heat from the intake? Just wondering.Thanks.
Click to expand...
Just a stray thought about something that could mimic vapor lock....

My '55 is supposed to have a vented gas cap but one of the last times I opened it there was a whoosh of air going into the tank.
If air can't get in thru a vent the fuel pump will have a really tough time pulling gasoline out. Especially after several minutes of driving (not idling) when the negative pressure will build up faster.
I'm replacing the gas cap, just in case.

.
 
Last edited:
"If the fuel in the carb.is boiling and thus causing vapor lock,is it a fault within the carb. or too much heat from the intake? Just wondering. Thanks."






Vapor lock isn't a condition that happens in the carburetor. It happens to hot spots in the fuel line and/or fuel pump. That causes a lack of fuel supply to the carburetor.
Carburetor fuel boiling is when a hot engine is shut off for a little while and the heat soak heats up the carb since fresh fuel isn't being supplied with the engine off. That can cause a hard restart when it's hot after being parked for a little while.


Sal
 
Yesterday I was checking to make sure that everything inside the dist.was ok. There is a bare ground wire inside there that is connected to the body of the points to supply ground to the points.This is connected to the points via one of the 2 screws that hold down the body/case of the points.This screw would not tighten up because of worn threads on it and therefore,the bare ground wire was loose too. I went ahead and replaced both of the 2 scews that hold down the points for safety.




I'm just wondering if the points were not being grounded securely,would that would cause the engine to shut off while going down the road.


I have done everything that I can think off and have done all that has been suggested to me here at this forum. Oh, one question? I noticed that the shaft of the dist.has some play in it.What kind of problem would this give me or is that normal?
Thanks to all.
 
If the ground wire for the points has a bad connection that could cause ignition problems. Same as a bad connection in the wire from the coil to the points.

Distributor shaft play... If you have a dwell meter connect it, there should be less than 5 degrees of 'bounce' in the reading or the distributor shaft bushings are worn out.
 
poolplayer1 said:
Yesterday I was checking to make sure that everything inside the dist.was ok. There is a bare ground wire inside there that is connected to the body of the points to supply ground to the points.This is connected to the points via one of the 2 screws that hold down the body/case of the points.


This screw would not tighten up because of worn threads on it and therefore,the bare ground wire was loose too. I went ahead and replaced both of the 2 scews that hold down the points for safety.

I'm just wondering if the points were not being grounded securely,would that would cause the engine to shut off while going down the road.

I have done everything that I can think off and have done all that has been suggested to me here at this forum. Oh, one question? I noticed that the shaft of the dist.has some play in it.What kind of problem would this give me or is that normal?


Thanks to all.
Click to expand...

dmsfrr said:
If the ground wire for the points has a bad connection that could cause ignition problems. Same as a bad connection in the wire from the coil to the points.

Distributor shaft play... If you have a dwell meter connect it, there should be less than 5 degrees of 'bounce' in the reading or the distributor shaft bushings are worn out.
Click to expand...


Correct. That ground wire grounds the upper breaker plate (and points/cond) (the plates rotate on a nylon bushing) to the dist housing for the needed ground.


376059


Let's try to start from SQUARE ONE as there is no reason for you to go through all of this.
 

Attachments

  • B9AF 12264-A - 2in Lgth.jpg
    B9AF 12264-A - 2in Lgth.jpg
    4.7 KB · Views: 39
Last edited:
dmsfrr said:
Distributor shaft play... If you have a dwell meter connect it, there should be less than 5 degrees of 'bounce' in the reading or the distributor shaft bushings are worn out.
Click to expand...


See the ILL-



376060
 

Attachments

  • DIST SHAFT BUSHING - Checking.jpg
    DIST SHAFT BUSHING - Checking.jpg
    61.5 KB · Views: 38
You must log in or register to reply here.
Back
Top