99 Ram 2500 van engine stalls or will not start

If you continue to have problems I would recomend taking it to a dealer or another mechanic who would have a scan tool with the vehicle specific codes (or able to pull car data from ecm). They will be able to identify which component on the BUS is dragging the system down. The most common of all is the connection on the back of the instrument cluster. Unplugging that for a few moments works in quite a few cases. Other than that, it's a guessing game if you don't have the proper scan tool.

I can't come up with any ideas right off hand, but some things NOT to do.
No water coling ideas :P
Don't stick any reflective insulation to it. Although it seems like a good idea at first, it will also hold heat generated by the electronics inside and fry it faster.
IF it is behind a plastic panel, go ahead and stick a small piece of reflective mat to the plastic, but just enough to reflect radient heat away (under and on engine side). Last thing you want to do is create a heat trap that ends up making the area even hotter!

I'm sure you could fabricate a sheet metal heat shield for the bottom and side that is closest to the engine and stick the reflective mat on the engine side of that, to reflect the radiant heat away from it. Space it an inch or three away from the ECM to allow for air flow to the surface of it. Any modifications like this would likely void the warranty, so it's best to leave it alone until it's no longer under warranty.
You could also rig a small 12 volt fan from radiohut to blow on it when the key is on. Position that so air from near the fender is blown on it, but at highway speeds enough air flows through there to blow anything away that's not bolted down.