Hello! I am new to this, I have an 06 Sportsman 700 that has overheating issues. My mechanic does not know what to do next. It had the HOT signal on display, fan quit working. It would not come on, had a new fan installed, then it still would not come on, but if you turned it off, waited a couple of seconds, turned key on, fan would come on, HOT signal went away, took it into shop, they installed a new AECM module, now the fan will not stop running. They also put in a new thermostat, still runs hot. they say that the incoming and outgoing lines are hot, rest of radiator is cool. I am at whits end, any suggestions?

 

Just because a new ecm module was replaced doesn't mean it can't be faulty. The main functions of the ecm are charging back to the battery and fan operation along with having internal circuit breakers that can short out. If the fan is running constant,I'd have them try another ecm.I've had to replace ecms on the some machines several times. Even the American made Sure Power modules that replaced the black Chinese modules can have problems.Another problem was trapped air on cooling systems that could cause them to run hot,but the fan shouldn't be running constantly.

 

Thank you old Polaris tech. I went to the machine yesterday, and the mechanic is at a loss. Put in a new radiator cap, did not help, now the fan does not come on when the hot light comes on, but if you turn machine off, and turn the key, the fan comes on, runs and cools down the quad, and then does not shut it off. He is going to go to the dealer, and see if he can call a tech at Polaris. I told him what you said, but he is not sure if that is the problem. But at this point he is ready to do anything. We even discussed having the fan coming on when I start the quad. Is this module located just forward of the handlebars? I thought on this year it was by the battery.

 

Item # 24.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse If the tech has an ignition switch in stock,just have him plug it in just to eliminate it as a problem.

 

I checked, and the mechanic already changed this out after he changed out the ecm. He is going to go to the Polaris dealer and see if he can talk to a Polaris tech at the factory, I do not have this in at the dealer, because they are a bunch of idiots, they were the ones that changed the fan, and did not check anything else, the mechanic took your advice and thinks it is a bad ecm module, he orders his parts from the dealer in town, and they are terrible on getting parts in, had to wait 2 weeks for the first ecm module. Boy this machine is really chasing me to Yamaha. My wife has a Grizzly 400 and we have not had any problems with it. My Polaris has been in the shop most of the summer, mostly waiting for parts.

 

I want to clear this up, the mechanic changed out a switch that was under the gas tank, not sure it was the ignition switch.

 

Update: I went to the shop on Saturday, they had changed out the ECM, and the new one was also bad, it screwed up the reading on the RPM's, and when you revved up the engine, the rpm's went lower? It showed 300 rpm's and when revving up the motor it went down to 200 rpm's. He is going to take it out and order another AECM. I guess on the first one, the fan would not shut off, and the charging would go down from 14 volts to 12 after running it for awhile. Is this still the ECM? He has not checked the ignition switch. Also it has a new battery in it. HELP??

 

It's the ecm module as it controls both the charging and fan operation!! Don't remember having any stator problems that could have an effect on this,just ecms that could be faulty straight out of the box..

 

Well, we are on the third ECM module, mechanic is going to check ignition switch as Polaris is questioning if the module is getting enough power, mechanic said last time, it showed 14 volts charging but when the fan came on, the longer it ran, the lower the volts went, down to 12.5 volts. He also said that Polaris said he may need to put in a resistor to let the fan and module sync up. But they did not tell him where the resistor should go? Any idea?

 

I had to do that on some early 800 Sportsmans that would heat up before the fan kicked on. Polaris engineer I talked to said to use a 33 ohm resistor wired inline on the thermistor sensor on the cylinder and see if it helped.Got a few at Radio Shack and it helped on the synchronization on the fan,but these were efi machines and had a two wire sensor plug,not the single wire thermistor that you have on the 700 carb model.Plus you might have him test the amperage on the fan as it kicks on and running. Can't remember on the 700,but if the 800 drew more than 15 amps,the fan was getting weak and starting to go out and needed replacement.Could have an effect on this if it is.Plus if he hasn't checked the resistance on the thermistor sensor,it could be a problem. Don't know if any of this would affect the drop in charging you're having,but seems after 3 ecms anythings possible,plus I'd even do a resistance check on the stator itself.