79 R model heater knobs

[JNabozny]

Does anyone have the 2 heater knobs for the 2 levers on the heater controls? Or know where I can get them? Thank you 

[Brocky]

Have you tried Barry at Watts Truck???  888-304-6225

[JNabozny]

I looked on the website, but I’ll call them tomorrow. Thank you 

[kscarbel2]

1 hour ago, JNabozny said:

Does anyone have the 2 heater knobs for the 2 levers on the heater controls? Or know where I can get them? Thank you 

Is the unit an Evans or Red Dot ?

[JNabozny]

On 1/25/2026 at 9:39 PM, kscarbel2 said:

Is the unit an Evans or Red Dot ?

That’s a great question lol.

[kscarbel2]

15 minutes ago, JNabozny said:

That’s a great question lol.

That's an Evans.

I'm sorry, I can't remember the 2790-HVxxxxxx part-number for the slider knobs. 

Red Dot has a similar knob, RD544500, but of course I'd rather look up the truck by model and serial, get the 2RD heater assembly number and grab the correct 2790- knob number from that breakdown and supercede forward from there.

[Vladislav]

20 hours ago, kscarbel2 said:

That's an Evans.

I'm sorry, I can't remember the 2790-HVxxxxxx part-number for the slider knobs. 

Red Dot has a similar knob, RD544500, but of course I'd rather look up the truck by model and serial, get the 2RD heater assembly number and grab the correct 2790- knob number from that breakdown and supercede forward from there.

Kevin, sorry to bother. Is that RD544500 Red Dot knob fit to the temp control levers (as on the above pic) or on the small blower control lever too?

[kscarbel2]

22 minutes ago, Vladislav said:

Kevin, sorry to bother. Is that RD544500 Red Dot knob fit to the temp control levers (as on the above pic) or on the small blower control lever too?

For example, they fit the slide levers on a Red Dot unit in an 1990 to 2000 MR.

My brain remains full of part numbers, a testament to the superiority of the Mack part system (Mack numbers were not arbitrary like Volvo, rather the part number structure had meanings). But even I can not remember them all, not having used them in years.

[Vladislav]

6 minutes ago, kscarbel2 said:

For example, they fit the slide levers on a Red Dot unit in an 1990 to 2000 MR.

My brain remains full of part numbers, a testament to the superiority of the Mack part system (Mack numbers were not arbitrary like Volvo, rather the part number structure had meanings). But even I can not remember them all, not having used them in years.

Thank you. I've a few those knobs lost off RD heaters in 2 or 3 R/RD-model cabs. And fan switches too. New ones check out cheap. So seems worth to stock up before they're NLA.

Yes, Volvo part numbers are blind. And long in digits to remember. I have never had a clue on the actual Mack ## meanings. Would be interesting to investigate the matter but difficult due to limited ability of the parts lists.