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Need a little help.... I'm stumped.

07 Grizzly 700 eps

The fan quit working, which isn't the first time, but this time is different as I can't figure out why.

I was originally only getting 4 volts to the circuit breaker in the back. Not 100% but I think thats going to be a mud in the fuse box issue, as I can't possibly imagine why else.

I jumped 12 volts to the wire but the fan still didn't work. I can jump a ground to the sender wire that comes from the ecu and the fan will start working. I have already replaced the temp sensor. but I jumped the wires across the temp sensor anyway and still no go.

Its almost like I've got 2 issues, the power coming from the fuse box and the computer not sending the signal. Has anyone ran into either of these two problems?
 

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I am having very similar issues with my 07. It happened to me once out in the woods. Had to limp it home. Changed fans because it felt sticky. After the new fan it was still giving me issue on occasions. Got the electrical tester out and found to be having similar issues as you.
I haven't had much time to research it any further. Since I wired an extra fuse block on my wheeler for other accessories and just ran an overide switch to the fan from the fuse block. When I notice my light turns on I flip the switch on and leave it on until the end of the day.
I know this is a band aid but it may help you until it gets figured out.
 

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Need a little help.... I'm stumped.

07 Grizzly 700 eps

The fan quit working, which isn't the first time, but this time is different as I can't figure out why.

I was originally only getting 4 volts to the circuit breaker in the back. Not 100% but I think thats going to be a mud in the fuse box issue, as I can't possibly imagine why else.

I jumped 12 volts to the wire but the fan still didn't work. I can jump a ground to the sender wire that comes from the ecu and the fan will start working. I have already replaced the temp sensor. but I jumped the wires across the temp sensor anyway and still no go.

Its almost like I've got 2 issues, the power coming from the fuse box and the computer not sending the signal. Has anyone ran into either of these two problems?
First you have to find why you are not getting battery voltage to the circuit breaker. there is a fuse that feeds that. The temp. sensor is just that, not a temp switch that you jump wires on. Disconnect the connector. The G/w wire should have 5 volts with key on. The B wire should have a good ground.
If ok. plug back in. With key on, measure the voltage agross the two wires.
degrees F/ Volts
46----------- 4.25
68 ---------- 3.75
100 ----------3.00
186---------- 1.00
This will give you basic idea of test results.
 

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Discussion Starter #4
First you have to find why you are not getting battery voltage to the circuit breaker. there is a fuse that feeds that. The temp. sensor is just that, not a temp switch that you jump wires on. Disconnect the connector. The G/w wire should have 5 volts with key on. The B wire should have a good ground.
If ok. plug back in. With key on, measure the voltage agross the two wires.
degrees F/ Volts
46----------- 4.25
68 ---------- 3.75
100 ----------3.00
186---------- 1.00
This will give you basic idea of test results.
Ok thanks... I'm out of town working for a few weeks but I'll give that a try when I get back. So the temp sensor tells the computer what the engine's temp is in the form of voltage, and then the computer sends a ground to the fan relay to turn it on when it hits a certain temp. Right?
 

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Ok thanks... I'm out of town working for a few weeks but I'll give that a try when I get back. So the temp sensor tells the computer what the engine's temp is in the form of voltage, and then the computer sends a ground to the fan relay to turn it on when it hits a certain temp. Right?
Yep, Exactly
It is an NTC sensor. (Negative Thermal Coefficient) That means as temperature rises, resistance goes up and voltage goes down.

Good luck
 

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Yep, Exactly
It is an NTC sensor. (Negative Thermal Coefficient) That means as temperature rises, resistance goes up and voltage goes down.

Good luck
Well... I finally got home and got to check it out more.

I borrowed my nephews 08 grizzly 700 (mine is an 07). I swapped our circuit breaker and relay and his worked an mine still didn't so they are not the culprit. I had already replaced the thermo sensor, but checked it also. Unplugged it read 4.7 volts across the plug. Plugged in, it read 2.7 volts at 70 deg, 0.81 volts at about 165 deg, and 0.46 volts at about 210 deg. Based off your explanation I assume this is what it's supposed to be doing.

I found an issue with the wire going to the circuit breaker at the fuse box with a wire loose. I fixed that issue but still not working.

One thing that I don't understand is on the 08 the wires at the circuit breaker only has 12 volts if the fan is actually running. Mine has 12 volts if the key is on. I don't understand what the difference is here.
 

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Well... I finally got home and got to check it out more.

I borrowed my nephews 08 grizzly 700 (mine is an 07). I swapped our circuit breaker and relay and his worked an mine still didn't so they are not the culprit. I had already replaced the thermo sensor, but checked it also. Unplugged it read 4.7 volts across the plug. Plugged in, it read 2.7 volts at 70 deg, 0.81 volts at about 165 deg, and 0.46 volts at about 210 deg. Based off your explanation I assume this is what it's supposed to be doing.

I found an issue with the wire going to the circuit breaker at the fuse box with a wire loose. I fixed that issue but still not working.

One thing that I don't understand is on the 08 the wires at the circuit breaker only has 12 volts if the fan is actually running. Mine has 12 volts if the key is on. I don't understand what the difference is here.
There should not be any current to the circuit breaker unless the relay is activated. if you have current with key on, the relay is stuck or activated or there is another power source going to that circuit breaker..
 
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