69 burb rear ac relay

[highwinger]

So I bought this 69 burb recently that has "factory air". Well I found it has rear air but not front (no vents or evap). I assume that means the AC isn't factory and the rear is an add-on albeit a factory system. Were they made with rear only?

I'm having difficulty finding any info online about the part,location and wiring. In fact very little acknowledgement of rear ac period. My Haynes book has a schematic showing the relay but doesn't distinguish between front & rear. Are they the same? Where do the two systems tie in together with sets of controls for the same compressor? I don't have front anyway, but am considering get the Old Air heater box swap for AC/De-Ice/Heat. Anyone with experience with them?

(enuf of my own thread creep) Other posts say the relay is a common problem when the hi won't work but the lo & med will. Does anyone have a pic or diagram of where I can find the relay or what to replace it with?

I've been reluctant to tear into it again since the overhead trough is brittle.

Thanks in advance,
Bill