[DAVE]

You have to be careful with my “advice” Davy. Parse the words. I did not say it is not the switch but I did say I never heard anyone that had a switch problem said it would crank but not start.

If it is the switch sometimes cycling it through the 3 positions will temporarily get things working as they should. But if current is flowing through the switch so the starter should engage I am uncomfortable with the assumption the switch is why the engine won’t fire. Assuming you have fuel to the injectors there might be another reason it will not start.

[DAVE]

I would like someone to explain to me how electric fans save horsepower.

I know Prevost has switched to them and I am certain that only when cooling is needed do they engage, which is no different than on coaches with an electric clutch.

I also know on low speed clutch equipped coaches move some air, but nowhere near the volume of air that is moved on the high speed. We rarely engage high speed going down the highway so the amount of HP used to drive a fan is likely to be far less than that of the high speed.

But since we cannot get an electric fan to operate without the use of energy it is probable that under low load conditions only modest amounts of electrical energy are required to keep the engine cool, exactly like what we see with the belt driven fans.

But when we climb long steep hills or drive into strong headwinds at high speeds the cooling demand is substantial so at that point a lot of air has to be moved and the power to run electric fans comes from the coach alternators and what they lack in power, possibly from chassis batteries which in the short term will supplement the alternator output.

But if it takes XX HP to drive a belt driven fan it takes a similar amount of power to drive the electric generator to create the power to drive the electric fan. The only difference I can see is with a control module that is precisely regulating engine temps only the exact amount of power to spin the electric fans to maintain a given temp is used and we won’t see the cycling of the fan clutch. When the fan clutch is engaged it is operating the fan at an air flow in excess of that which is needed so we see the temps drop until the cut out temp is reached so that suggests the fan is using more HP than needed and is not as efficient as electrically driven fans that can be controlled to such an extent that only the exact amount of air flow needed is provided.

I think it would be interesting to learn how the electric fans are set up and regulated. I would hope they are more reliable than the fan clutch Prevost installs.

[DAVE]

Pres, go to Unity Parts dot com. Your pump will b $2670. Sure Marine $5670.