rlrenz
Explorer
You have the V-MUX system. It is manufactured by Weldon Brass Company. Re-programming it gets expensive, but if you leave it as-is, it will probably panic if your (non-existant) oxygen bottle pressure is low. Parts for it are available, but a new display runs about $900. Components are available on eBay, and sometimes as ambulance dealer surplus - check www.fostercoach.com for ambulance parts.
I have some operating instructions I'll post later today.
I have some operating instructions I'll post later today.