Okey cool. I assume we're talking about the freeplay version, right? I'm pretty sure your problem has to do with pump guy, if he cannot be found by the script, the commands disappear. The principle is that you need a working pump to spray water, thus when no pump guy present/found > script disables cool/extinguish commands)
Couple of questions, to see if I can locate the source of the problem:
1. Just to be sure, does the fire engine have a child with the name "pump_controller"?
2. Does your fire engine have the command "VcmdPumpSwitch"?
3. Do your firefighters have the command "PcmdPumpSwitch"?
4. When the pump guy is working on the pumps, is he in a looped animation where he slightly bends forward to give the impression he controls the pump (actual anim is called "useextinguis")?
5. If you use the 'Rapid Deployment' command to undeploy the fire engine again (when hoses are connected to it), does the pump guy enter the vehicle too?6. Does your fire engine have any other custom complex commands? If yes, which ones?
You are a genius sir. I never knew I had to assign the engine a Vcmd. Thanks for the help.