Did a continuity test on the two fused battery leads to the solenoids. One is in deed open.

 

Hmm, you say you have a 2001.5, RA shows a different setup than my 97, go to 2001, Dodge, 2500 5.9 diesel and look under electrical, then axillary heater relay. This is what they list: AIRTEX / WELLS Part # 1R1679 More Information About this Part {#20364, 5086631AA}
(Intake Air Heater Control)


That shows a single, I would say you would need 2 if that is what your old ones look like, the good thing is they are only 20 bucks each.

I believe yours may operate differently than the older units like mine, I know somewhere in the 2001 year they changed it so that the PCM applied 12V, perhaps this is it?

Anyway, go look and see if the picture resembles your old relay. If not, then look at this one:
From 1999 Dodge 2500, 5.9 diesel, same category, called Universal Relay
STANDARD MOTOR PRODUCTS Part # RY441 More Information About this Part
Htr. Air Int.

This is the one they list from 1994-2001, it is the one that the PCM drags to ground to engage.

 

I don't have the old one right in front of me but that DOES look an awful lot like it. There really isn't any rocket science about it. Power comes in, power goes out, ECM turns it on and off.....

 

Looks like Napa lists the same part, and for a buck or so cheaper. Once I verify if I need one or two, I'm going to go that route.

Is the fuse in the fusable link replaceable?

 

Just ordered my heater from these folks today.

http://hoeslidiesel.com/store/page2.html