Question:
My ambulance cools great in the front but cool air does not blow out the rear AC unit,
what is causing this?
Answer:
More than likely the expansion valve needs replacing another possible cause of this is if the heater valves are stuck in the open position allowing hot water to the heater coils. Lastly if the particular vehicle uses a underbody condenser then it needs to be checked to make sure the fans are blowing.
Question:
When I start up my ambulance it shows low voltage for the first few minutes and then every thing goes to normal, is that supposed to happen?
Answer:
Yes, that is normal. The glow plug circuit has to come up to nominal temperature after start up and will take almost all of the voltage the alternators can put out during this process. Keep in mind that this time period will increase when temps are low and that any voltage sensitive systems (strobes or sirens in particular) may not function at all during this time.
Question:
We have a 2006 E350. Need to know if switch on side of driver’s seat turns off all accessories or just the front panel. I have a draw on the vehicle that goes away when I disconnect the positive battery cable under the vehicle going to the front where the seat
switch is located.
Answer:
On modern ambulances, the disconnect switch is just for the ambulance conversion and should only cut off power to ambulance accessories. In this case, we checked the inverter and it was drawing power when the switch was off.
Question:
Have a 2006 E350. A/C works fine. When turning thermostat to heat, blower quits working. Found bad thermostat and replaced. Now, when turning on the heat, circuit breaker is kicking in and out. I have schematic for this vehicle, but it doesn't seem correct. Has single unit and has two relays inside vent screen. Schematic doesn't show external relays. Tried replacing relays, but problem still exists. I'm assuming there is only one blower motor on this unit. Is this correct?
Answer:
Yes, there is only one blower motor. First, try replacing the breaker, as auto-reset breakers will wear out or weaken over time. Then, if that does not work, double check the wiring, since the breaker was not kicking in and out when A/C was running.
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