Is there a way to test these things to tell if they are good?I think its whats causing the trouble but would like to know for shure before spending the money for a new one.Thanks

 

Take it out and go to auto zone or oreiley's, most auto part stores can test them for you.

 

They will test it for you, but sometimes it's heat related and will not fail until it gets hot. So that's something to think about if it's intermittent.

 

So there is no way to test it at home with a multimeter any way?

 

In the Chiltons manual there is a resistance/continuity check that can be performed with it removed. As was said however, if it's heat causing the unit to fail it may still check OK. Sorry, it's not a lot to go on.

 

You can check its output with it in-system using a multimeter. If you go to Autozone's website, they have some decent step-by-step Duraspark troubleshooting guides under "Vehicle Repair Guides" that you can access by searcing for your vehicle.

There is no effective way to test it out of the truck with a standard multimeter; you will only see reflected impedances from non-linear devices in the circuit and they don't really say anything about the integrity of the device.

A while back my '77 LTD would randomly shut off while driving. It'd coast to the side of the road and by the time the car rolled to a stop, it would start up again with no problem. This happened once a day or so. It did turn out to be the ignition module. But problems like that could be anywhere - I imagine that if your ignition switch was misaligned just enough and you went over a bump, that could turn your truck off. I got lucky!

 

If you use this vehicle a lot, there is nothing wrong with carrying a spare module around if it turns out it's not the problem.