Fried EGR Time Delay Switch?

[Tom Norman]

The voltage regulator went south recently on our 1988 B350 Dodge Ram van with the 360 engine, and the uncontrolled voltage fried my battery isolator and it looks like it also fried the EGR time delay switch. Damage to the battery isolator was obvious; one of the isolator posts overheated, melted the epoxy resin, eventually causing an internal short and major arc.

I examined other components on the firewall and it looks like the EGR time delay switch was also damaged. Not as bad as the battery isolator, however, it was obvious that the epoxy resin containing the internal components had become very hot. Some of the epoxy resin had melted and I could see droplets of melted epoxy resin on the firewall underneath the EGR time delay switch.

I plan on replacing the EGR time delay switch, but what are signs that the switch is, in fact, toast? I've noticed that the van is a bit harder to start in the morning, and it's also harder to start when hot. When hot, it takes a lot of cranking to get it to start. Once started, it runs smooth as silk. It just takes a lot of cranking do get it to fire.

Are these symptoms of a bad EGR time delay switch?

[B-300]

I would suspect the ignition module may be toast since it must work whether hot or cold... The EGR time delay relay is only active during a hot restart, when cold the vacumn to the EGR control circuit is cut-off when cold, so cold start shouldn't be affected.

[Tom Norman]

Hi B-300,

Thank you for your input; you are 100% correct!

Looks like the uncontrolled voltage killed the ignition module too. Upon closer examination, the ignition module has tiny trails of melted epoxy resin that leaked out from inside the module. I'll be replacing the ignition module AND the EGR time delay switch.

Thanks again for your help. Hopefully, nothing else was damaged!!!

Tom