I had a LOT of trouble with the MSD in my '82 Ramcharger. I had it all mounted in the cavernous area under the driver's seat so no problems with heat. I had it wired so by just switching a couple of wiring plugs under the hood I could be running on the original mopar electronic ignition system. Whenever it died, that was the solution. The benefit from running the MSD was so minimal and the hassle of getting out and changing the wiring so great it made me eventually abandon the system. I suspect the box itself was intermittently bad but I never pursued getting it fixed or installing a new one. Dad had similar problems and had his repaired at MSD as he lived nearby and it worked fine afterwards.