I bought an 06 ccsb while back
And neither side heated seats work.. All power adjustments work on. Both sides, jus not the heated seats.. I checked ign 3 fuse and it's good, but I can't seem to find the problem. Any help is always appreciated!!!
Can you fill out your signature block showing year and model/RPO code (I know you mentioned it's an 06 ccsb and that's helpful). Assumption would be that it's an LBZ but there are plenty with gassers. Include any mods and all of that stuff so that we know what we're dealing with. Location is good too because many of us have Tech II's or other diagnostic equipment and might be able to help out. If you were near me I'd throw my tech II on it for a cup of coffee and see what the module was telling us. I'm no expert on the Dmax (my field is Heavy Duty automotive) but I have the test equipment and a full set of factory shop manuals for the LBZ.
If you have a DVOM meter, I would check the connections to see if A: you're getting power first. If you are getting power to the switch then check from the switch down to the connectors to the heating mats. There is a connector under the seats. IIRC, it is an 8 pin white connector, but it may differ between MY. Once you've verified you have power, you've also accomplished a continuity test. If everything checks out, check the resistance of the mats. If they are out, then it will be mats. If you have a break in the wires anywhere, then you will find that out during the continuity test.
I'll do that when I get home from work. But if I remember correctly, the day I bought the truck they worked.. And I think I read somewhere they are wired in a series starting with passenger side correct?