I hope it isn't like the resistor in my 99 dakota. Gotta pull the whole dash out to get at it, i found it by accident when I had to replace the heater core. It's in the cowl way up high behind the dash.
I have had several 87-96 dakota's, have replaced a few resistors but not many. At least easy access. I had one dakota (can't remember if it was the 92 or 93) I replaced the one on that truck twice.
The one on my Durango is much easier access in bottom of heater box but that one is a once a year job. I have replaced the pigtail to it twice in 7 years, and someone else had replaced it before we bought that one.
In the 70s and 80s trucks, burnt out connectors throughout the heater system are extremely common. I don't ever remember replacing a resistor on the (too many trucks to remember) 70s or 80s ones that I have owned.
I currently have an 85, factory non AC that I am working on, the wiring on this one is very screwy thanks to the prior owner, I'm kicking around the idea of adding AC to this one while I am fixing it up. Depends on what donors I can find in the local junkyard to rob everything under the dash from. I think my boy still has the whole wiring harness from an 85 ramcharger that I can get all the wiring I'd need for my truck if I decide to go that way