Fan does not run

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huron52

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I require some tech advice here. We are Missoula MT and the bike has over heated to a point of pushing out rad fluid.

Where is the senser for turning to the fan?

HELP!

 
no.... We can't get the fan to come. It doesn't come at 4 bars like it should.... So we figure it is corroded contacts or the wire loose on the senser which is suppose to be on the rad somewhere

 
Steve here...

We need to know where the temperature sensor is located. We can't see any sensor off the rad, so it must be off the block or the head?

Anybody with a Gen 1 service manual have a peek for us please!

 
Here's the Microfiche: See #16 & 18

Fjr_ThermoSensor.jpg


Fjr_ThermoSensorDiag.jpg


Sorry I can't help you more.

I believe the temp sensor is located on the RHS end of the coolant pipe sitting on top of the rocker cover, it's got a green color connector in all Gen FJRs.

 
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Or you may be able to Bypass the Fan Relay:

The relays are up under the nose cowl on the back side of the intrument panel. On the GenI the fan relay is furthest to the right.

The four wires connected to the fan relay are:

Red

Red/White

Brown/Black

Green/Yellow

The relay is located near the forward end of the battery, just below the main fuse.

 
I assume the first thing you did was check the fuse.

If you can't or don't want to tear into the fairing right now, then maybe you could run another power lead to the fan, and operate it manually.

Just go from battery, threw a fuse, threw a switch mounted on the bars, then to the fan. Just make sure the added switch and wire is heavy enough. I don't know about Gen I, but if it has 1 fan then it may have bigger wire (higher amps) going to it.

Of course this would only work if the fan itself is OK. So before anything take a piece of wire from the battery to fan, and make sure the fan is good.

Just a thought;

Art

 
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The output of the coolant temperature sensor goes to the ECU, then as required the ECU turns on the fan relay. When the engine is cold go to the diAG screen and go to Code 06, read the value on the lower part of the display, this is the coolant temperature. Warm up the engine, shut it down and once again go to diAG Code 06 and read the coolant temperature. This will tell you if the problem is the sensor and if the ECU is reading the sensor. If Code 06 does not show the correct temperature you are looking at sensor/sensor wire/ECU issues. If the ECU does not read the coolant sensor due to open or short in the sensor it will default to 60º all the time.

IIRC, the wire attachment point on the sensor is exposed and could be damaged. If Code 06 reads correctly both hot and cold then you are looking at the fan relay, fan fuse or bad fan motor.

As mentioned in a previous post, the fan relay is up next to the battery. If you can find a Radio Shack they sell 20-30 amp toggle switches, this is the size switch you would need if you decide to follow road runner's suggestion. I would recommend 10 to 12 gauge wire, or if you can find lamp cord this would be more flexible and work fine. Lamp cord will have one of the two wires molded with ribs to help keep polarity straight. The liability of lamp cord is lower heat tolerance and chemical tolerance of the insulation. This is a field MacGyver, it doesn't have to be pretty, just functional.

 
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Steve here...
We need to know where the temperature sensor is located. We can't see any sensor off the rad, so it must be off the block or the head?

Anybody with a Gen 1 service manual have a peek for us please!
Item 3.

TempSense.jpg


 
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and that, ladies and germs, appears to be THE answer! complete. inclusive. and easy to understand.
(home run!)
Grandslam! Hey Huron.. keep your knees in the *breeze* and the bike won't overheat! :D

 
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I was going to suggest the 'manual' fan control as well, but was thinking a lighter gage wire and switch to the fan relay trigger (assuming the relay is good,) would be easier with materials I carry with me and I assume you guys have.

 
I was going to suggest the 'manual' fan control as well, but was thinking a lighter gage wire and switch to the fan relay trigger (assuming the relay is good,) would be easier with materials I carry with me and I assume you guys have.
Good idea. Have you ever tried to access the fan relay on a Gen I? The Green/Yellow wire is the fan relay wire that gets grounded to activate the relay. I do not recommend tapping the Green/Yellow wire without isolating it from the ECU connector. To do this the wire would have to be popped out of the ECU connector which is a lot of work, and I'm not a fan of cutting the wire. I'm not sure how the ECU would take having an external chassis ground switched on its output pin if it is not disconnected. Sometimes though, ya got to do what you got to do.

 
I was going to suggest the 'manual' fan control as well, but was thinking a lighter gage wire and switch to the fan relay trigger (assuming the relay is good,) would be easier with materials I carry with me and I assume you guys have.
Good idea. Have you ever tried to access the fan relay on a Gen I? The Green/Yellow wire is the fan relay wire that gets grounded to activate the relay. I do not recommend tapping the Green/Yellow wire without isolating it from the ECU connector. To do this the wire would have to be popped out of the ECU connector which is a lot of work, and I'm not a fan of cutting the wire. I'm not sure how the ECU would take having an external chassis ground switched on its output pin if it is not disconnected. Sometimes though, ya got to do what you got to do.
Good points! I was just thinking about what I carry I.C.E. and I don't have any heavy gage wire or a high amp switch. I'm sure there will be somewhere in Missoula to pick that stuff up. Maybe I'll think about adding this to my kit and quit trying to be 'elegant' with my roadside solutions! :D

Rob, Steve and Tom,

Get a move on! I don't wanna wait all day at Lake Louise for ya! :p

(Course I am still 2 hrs away once I'm ready and decide to roll. :rolleyes: )

Edit: Ignore that! See you on the Island!

 
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Ok. To all who have waded in with help here's what's up. We diagnosed the sensor is ok. The fan motor is ok. So without tearing off the whole front clip we did the next best thing. We field dressed the wound. In other words we added an inline fuse and put on a manual switch. Back in business! We'll be on the road within 1/2 hour.

Thanks for all your help.

Rob

 
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