Repeated Distributor Failure

I have a 1992 Dodge Colt with a 1.5 liter engine and 160k miles. The distributor contains both the coil and the module/switching transistor/control unit (whatever you want to call it). Over the last three years, the unit has failed repeatedly (I’m on number four or five). It usually lasts about a year before it conks out, and there is usually a few days’ warning when the spark gets weak and the car begins to miss, but eventually the spark fails completely. I’ve replaced the ignition switch (thinking I might have a problem there), the radio noise suppressor (it’s connected to the module), the cap, and rotor, plugs, and high tension wires. Any suggestions? Could this be an engine control computer problem?

Are all the DC input values correct? Are all the units comming from the same place? (when they fail are you returning to the retailer for warranty replacement)? For some reason many posts with repeated component replacements fit the mold of part failure,warranty replacement,part failure warranty replacement on and on.

Just for funzies, check the alternator for a/c output. There shouldn’t be any a/c.

The units have come from two different places – one place is owned by a buddy and I didn’t have the heart to bring the third one back, so I bought # 4 from a different place. It lasted the shortest – I bought it in November and it conked out last week. And I took it back. The coil impedance was within spec, but the switching transistor didn’t seem to be working (the manual has a checking procedure).

I’ll check the DC inputs.

The alternator (came on the car) was replaced last June, but the replacement failed in about three months.

How would I check for a/c output?

I think you need to fine an electrical specialty shop in your area. There is either too much current, the wrong type of current (AC/DC) or too much heat breaking down all these electrical components. Replacing parts as they burn out is not getting to the root of this problem.