Electronic ignition help!!!

[spoolinhard]

I'm not a member of the truck board, but think this is still relevant here. I Have a 74 ramcharger I'm attempting to put back on the road. Truck starts then dies immediately after letting off the ignition. If you hold the ignition in the start position, with the starter engaged, it runs. At the ballast resistor, 3 of the 4 terminals have 11.xx volts to them in the run position. The forth terminal that is connected to the secondary ignition (direct from the column ignition switch) has 3.xx volts with the ignition in the run position. If I run a jumper wire completing the circuit of the secondary ignition wire, at the resistor (top to bottom), the truck runs. I have tried 3 different used resistors (none have visible damage or signs of excessive heat), still doesn't run without the jumper.

I have checked the connections at the firewall and at the ignition switch connector at the base of the column, those are good. I'm thinking a bad column/ ignition switch. Thoughts?

Shouldnt the direct line from the secondary ignition at the ballast resistor, also have 11.xx volts in the run position?

 

[R413]

What is your battery voltage?

Why do you have just 11.XX? Is your battery low? Or do you have that much voltage drop?

Usually this action means Replace the ballast resistor

 

[spoolinhard]

12 volt battery. 11.xx is voltage drop.

 

[MWbirdLOVER70]

I’m voting ballast

 

[hunt2elk]

Your issue sure sounds like a bad ballast resistor. Did you ohm them out?
I doubt it is related to your problem, but your voltages are to low. Should have 12.6 from a healthy battery, and only a couple tenths voltage drop. Around 14 volts when running. So something is not right there.

 

[R413]

12 volt battery. 11.xx is voltage drop.

A new battery is 12.6.
A new battery that has just run a while is 12.8
An old battery can be 12.4 and still function.

A running engine should be somewhere in the 14"s for voltage.

So can you tell us your actual battery voltage. Now start the ramcharger with a jumper wire and tell us what the voltage is.

 

[kiwigtx]

13.6 - 13.8 Volts is a good battery on charge

14.4 - 14.6 Volts is a good battery in a vehicle with engine running at fast idle.

also have 11.xx volts in the run position?

That suggests to me that you have either a lot of Voltage drop between the battery and the resistor - as in bad connections at the bulkhead connectors and steering column etc.

OR

Your battery is on it's way out.

 

[spoolinhard]

For all inquiring, much cranking on the battery has been done working on this problem. A more accurate reading is probably 12.2 at the battery. for all the cranking, it has not been charged. I have not checked ohms on ballast. Calling it a day right now, will check tomorrow. Also, one last info drop. Ignition switch secondary wire in run position is 3.43 volts. When in start, wire bumps up to 10xx volts, but drops back to 3.4x volts when let off of start Shouldn't this be 12v in run? The secondary ignition should be 12v to the ballast, and lower after that, to go to the coil, as the coil would overheat and fail with a constant 12v.

 

[spoolinhard]

Ohms .05 on secondary side, .01 on primary side ballast resistor

 

[Dave6T4]

Defective magnetic pick-up in the distibutor will do the same thing.

 

[Kern Dog]

Here is a great collection of charts on batteries:

 

[Bee1971]

In the run position , check your voltage at the bulkhead wire coming from your ignition switch
I don’t know the color of that wire for your vehicle

Yes in the run position , you should have at least 12 volts at the bulkhead wire (Engine running 13.5 to 14.5 Volts) that wire then feeds the Dual Ballast Resistor in your application - Then voltage drops thru the Ballast Resistor in the run position to your ignition coil - Usually to around 7 - 9 Volts at the coil in the run position

 

[Bee1971]

Ohms .05 on secondary side, .01 on primary side ballast resistor

Dual Ballast Resistor

5 OHMS that feeds the factory 5 pin ECU Ignition Module

.5 OHMS or 1.2 OHMS that feeds the Ignition Coil

 

[Geoff 2]

If the engine runs [ key in any position ], then it is not the pick coil.
Also, if the engine cranks ok.......the battery is ok!!!
Could be ign sw or poor connection/connector.

 

[spoolinhard]

Ok, some closure to be brought to this thread. The more I started testing circuits and checking volts, i found that the problem was at the ballast resistor and that things didn't add up. The problem ended up being an orienting ear that was broken off one of the wiring connectors that plugged into the ballast resistor. Without the ear, the connector was allowed to be plugged in upside down. When I realized this, I changed the orientation and the truck fired up and quietly idled.... Like it was mocking me for being such a dummy.
Thanks for everyone who submitted input