Converting Chrysler CDI to Automotive ignition question

[ecu1984]

I have read numerous threads on this subject and have a 1981 85 HP Chrysler that currently has no spark.
I do not have points in mine but i have the "preamp" in place of points. Can you swap mine over to 12v auto
or can you only do it on the ones with breaker points?

Thanks
Rick

 

[Frank Acampora]

Re: Converting Chrysler CDI to Automotive ignition question

You need points and you need a distributor shaft and rotor with the cam on it. The rotor, cam and shaft are epoxied together and exsit only as an assembly.

The pre-amp is actually only an electric eye that sends a signal to the CD unit to dump the capacitors into the coil. BEFORE blaming the pre-amp, check out the other components. There is no way to check for a bad electric eye, you must substitute a known good one into the distributor.

With the ignition on and distributor belt disconnected, if you spin the pulley, you should see a small voltage fluctuating on and off as the eye is covered and exposed at the white wire terminal on the distributor. You need a special meter to capture the low voltage pulse and, even if you do see it, this does not mean the pre-amp is good.

 

[fucawi]

Re: Converting Chrysler CDI to Automotive ignition question

Frank is right as always but it is possible to use the module as this is just an optical switch ...it turns a small transistor on and off inside the unit...you need to test the output of the module ..oscilloscope and then build an interface to a vehicle CDI unit or more basic transistor swiched coil ...see the post Never ending supply of CDI units.......If you dont have the skill to do this then as frank says you need a dissy with contacts and remember you cannot use the existing coil as its primary resistanace is only about 0.3 ohm .. a 12v coil will be about 3 ohm