Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 M3W cooling fan amp draw.

Does anybody know how many amps the stock cooling fan draws?

As we all know the X Wedge engine produces a lot of heat. Even with less restrictive exhausts my engine does not run as smoothly when I’ve driven it for awhile because it still gets too hot. From what I’ve been reading high output fans placed right behind the highest temperature portion of each cylinder is the most effective way to reduce cylinder head temperature. More effective than oil coolers.

I’m considering removing the stock ECU controlled fan behind the engine and installing Love Jug fans hard wired directly to the battery with switch and bypassing the ECU control so I can turn them on as I desire. See pic below. Each Love Jug fan only draws 1.6 amp.

Is there any harm to ECU function if the fans are disconnected from ECU control. Obviously I will be turning the fans on with slow speed driving when the ECU would normally turn the fan on but also after extended driving when I feel the engine is too hot which I can tell by how smoothly the engine is running.

Appreciate your thoughts.

Doesn't sound like a good idea to me and that's ignoring the cosmetics and orientation of engine in M3W.

If the alternator can cope (which it can) then the more amps the fan takes (roughly equal to airflow) then the better

Hi Richard,

I’m here to learn from other’s expertise. I want a reasoned approach why or why not.

Please explain why you don’t think it’s a good idea.

From a cosmetic point of view remember this is the back of the engine. Also remember the airflow over the back of both cylinders is poor.

I appreciate everyone’s thoughts on this.

Thanks.

I am curious as to the engine not running smoothly after a while. I drive mine in 80-90F ambient temperature through the steep mountain roads here at high elevation so producing quite a load on the engine for up to 2 hours (then I need to stop) and do not experience not running smoothly, are you sure it is the heat?

That’s a very good question Bruce and I don’t have a definite answer to that. I’m presuming and experimenting. In the Harley forums there is quite a bit of discussion about high engine heat and performance including pinging and smoothness of operation. It might be something unique to my engine. Interesting that somebody else is not experiencing that issue. Nobody has been able to find any problems. It’s a subjective sense as to how the the engine is running. There are times when I first start out where the engine is as smooth as can be as manifested by lack of vibration throughout the vehicle. When I’ve driven the vehicle for a while and the engine gets hot the engine just doesn’t seem as smooth as sensed by more vibration throughout the vehicle. It’s not that the engine is missing with acceleration. That doesn’t happen. I do get some pinging with acceleration in third gear. Even though I have an ECU tuned for Stage 2 a proper computer monitored tuning would be great but in the states no body has that facility for a M3W like Krazy Horse.

Thanks for your question.

The stock cooling fan runs when the engine is over 100c and speed is below 10mph.

Above 10mph the plastic shroud ducts air behind the cylinders. When MMC introduced the cooling kit they published test results showing the effectiveness of their setup

Thanks Red Leader.

I think excessive engine heat in these big V twins must be an issue. Why otherwise are all these products available such as oil coolers and fans to reduce cylinder temps. As Red Leader pointed out Morgan itself felt compelled to put a fan in the back and top shroud to redirect air flow to the back air fins. I’m wondering if this is enough in my vehicle. I personally feel what is happening is the spark plug electrode and top of the cylinder wall is becoming too hot causing causing predentonation which would definitely create abnormal vibration. I would like to install high efficiency fans I can keep on longer during my drive. I certainly could be wrong. I’m considering installing the next step colder spark plug that would dissipate heat from the electrode faster and watch closely to see what effect this has. If the symptoms improve that would say a lot about the temperature as a causative factor. I’m willing to experiment.

I’m asking about the amp draw fron the stock fan because I don’t want to overload the existing electrical system by installing different fans that might have a higher amp draw than stock. I suspect the stock fan probably draws more amps than the Love Jug’s cumulative 3.2 amp draw.

Hi Richard,

I hope you don’t take my response to you the wrong way. You may very well be right that it’s a bad idea. I just want to understand why so I can critically reason this for myself. Some of us are left out in the woods so to speak to try to figure some of these things on our own rather than go to a dealer for every sniffle. Actually that’s part of the fun of having a M3W.

It’s also why this forum is such a great support for M3W owners. I have learned many things on this forum that have allowed me to be more self sufficient regarding the care of my M3W.

Thanks for your input. I do understand that just a subjective bit of sage advice, “ Don’t do it “ is worthwhile as well.

Sorry but thought I'd explained already Sportster, albeit briefly. You are concerned about excessive cylinder head temps but want to fit smaller, lower current fans and operate them manually. How will these cool your engine better given they appear to be for lower capacity HD engines with cylinders in tandem to airflow

Your S & S engine ex factory has a skipfire function when excessive head temperatures are reached where it alternately shuts down one cylinder then the other, a crude and inconvenient system.The urban cooling kit introduced in 2014 was to virtually eliminate this action with automated head temperature monitoring at speeds below 10 mph. Why would you want to go a step backwards by removing it in favour of above

I did previously own a 2016 build M3W from new covering 9000 trouble free miles, most of those with MMC stage 1 kit fitted admittedly.

I appreciate YMMV with regard to ambient temperatures and driving style but if you can prove absolutely that cylinders are running above recommended temperature then surely better to tackle the problem at source by finding out why. Failing that then fitting an oil cooler would be a far better direction to go in whilst keeping OE fan.

Hope my comments are viewed as helpful rather than harsh.