Here is my version of the C303 electric fan. Relatively easy conversion, the Volvo electric fan is one of my favorite for conversions like this and the same one I use on my Unimog1300L. This Volvo fan is found in most 90's model Volvo cars and is easy to pull. The fan moves enough air at low speed to cool the truck. High speed will be good for really heavy use but will likely be used very rarely. The sensation of driving the truck with an electric fan is worth every penny for this conversion.
Just a quick follow up now that I have my fuel injection completed.
The Volvo fan works perfectly. It really only needs the low speed setting, I still have it wired to come on full time at the moment but will be changing over to a PWM fan controller soon. The truck barely breaks 170*F right now and I really need it to warm up a bit more for the fuel injection to really work efficiently. Changing to an electric fan is a huge upgrade for the C303 and I can't recommend it more highly.
Sorry for the late response, yes I am running a converter. But you can run the Volvo fan on the low speed with 24V indefinitely. However that is a lot of cooling power and you will find it hard to stay warm.
Klug wrote:I guess it means the GM ECM can not control the fan?
No, the GM computer does not control the fan. However there are some work arounds that will let you do it with the GM computer but it's not ideal. I am using a Derale PWM fan controller now. The electric fan runs very rarely at more than 50% unless you are really pushing the trucks limits and it over 90*F. At idle in 95*F the fan barely comes on.
Below is the Temp log from my EFI computer. This log was started at about 5pm sunday 8-7-16. The route took me from my house out to the George Bush Tollway here in North Dallas. The majority of hte run was on the tollway to work the truck above 60mph. Max speed was 72MPH on GPS (over-sized tires helped speed but hurt temps). The max temp is 220.5*F which is where it stabilized. Temps were being taken from the deepest darkest hole in the coolant system which will be showing about the hottest point in the coolant system. Im no engineer but I would say a single fan setup in Pull configuration with a proper shroud works just fine for the majority of the C303 population. Quite frankly I don't care to drive this truck in these high ambient temps anyways so I take my motorcycle or air conditioned Unimog. Ultimately however I do plan on adding a decent sized oil cooler to take the edge off when I find that I am forced to drive this truck at these temps especially once I get around to putting in my higher speed gears sitting on my desk.
Thanks for your reply. Where are you in Dallas? I am in colleyville (by grapevine, south lake). I have a C304 that I bought last June. Glad to hear another C owner near by. Be great to meet and talk shop some time. I am interested in the EFI set up you have as well.