[74DDS]

I have a problem, whenever I start my car it will crank jsut fine but it won't fire till I let off the key. I don't know what could be causing this because I jsut replaced my voltage regulator because it was faulty, and rechaged my battery because it was drained by a problem caused by the bad voltage regualor. It will happen no matter the temp of the motor. So what do you think? Ignition problem? Any ideas welcome.

 

[azz7772]

ignition box 8)

 

[HemiDemon]

It's your ignition switch. When the key is in the start position it places a full 12 volts on the coil to increase the spark voltage during cranking. As soon as you release the key that circuit is broken, then the coils is powered through the ballast resistor. During this time the coils receives a lower voltage.

Your engine doesn't fire while cranking because the ignition switch is not passing the 12 volts to the coil while you are cranking.

Good luck,
Bruce

 

[VIN_VL29U]

If it's a dual ballast resistor, the start side could be bad.

 

[74DDS]

Is there any way to test these items to see if they are bad?

 

[HemiDemon]

If you have an ohm meter, you could pull the wires off the resistor and measure it. The resistance should be less than 1 ohm. You can test the ignition switch by using a volt meter to measure the voltage on the + side of the coil. While cranking the voltage should be 10 to 12 volts depending on the condition of your battery. When the engine starts (and it will because it's a Mopar) the voltage will drop to 6 - 9 volts. What you want to see is a higher voltage while cranking than when it fires. If the voltage is zero or very low during cranking, it's probably the switch. Check your fuses and fusable link too.

Good Luck,
Bruce

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[74DDS]

I'm going to show my lack of IQ here, but the ballast risestor is the little ceramic thing that has the 4 connections goin into it on the firewall correct? And which one is the starting side of it, like you said to test. I feel stupid asking it, but i need some clarification.

 

[cu440da]

I wouldn't even bother testing the ballast, just get a new one. If it doesn't fix it then you have a spare to keep in the car for when it does go bad.

 

[HemiDemon]

Yes, the ballast resistor is the ceramic block. The resistors run length wise. With the key in the OFF position, pull the upper right wire then check the resistance accross the two top terminals on the resistor. You should read about 1 ohm or less for a good resistor. Then replace the the wire and repeat the procedure on the lower two terminals. I tend to think that the resistor is not the problem. If the resistor was the problem, when you crank it the engine would fire then die as soon as you released the key.

Bruce

 

[NitroFixx]

Hook up a test light/voltmeter on the leads going the ballast, disconnected, one at a time. See if you have voltage when key is in start and run positions.

My car loves to lose the connection at the bulkhead for the start positiont to the ballast, so the engine won't fire until you let off the key.

Check that out and also check you bulkhead connections for the start/ignition circuit. 

 

[Guest]

Yep - my money is on the ballast.

 

[Guest]

ignition box    8)

[]{} had the same problem. new box no problem. thats if you have electronic ignition

 

[74DDS]

Well I replaced the ballast resistor and it seems to start a bit better but not quite, i noticed when I replaced it that re previous owners had wired a jumper between the top and bottom parts of the resistor, it wouldn't fire without that wire jumping the two halfs of the resistor, odd to say the least. I'm almost to the point of cutting every wire out of the car and re wireing the whole thing, it so &%*^#@ frustrating because there are so many wires that aren't connected to anything and that could be shorting out and causing this AHHH!! Plus the wires that are being used are so spliced up that it changes color and guage going from the alternator to the fire wall, so please help before i rip out all my hair. Thanks.