Temp sensor: where, and how, ground connection fix?

[SgtSlag]

My temp gauge is not working, but if I ground the wire to the engine, as per the FSM, it deflects from C, to H, as it should. In the Tech Tips booklet, it discusses adding a better ground connection to the sensor assembly(?). No photo's, no real help. Sorry, folks, but I cannot see the sensor, even after removing the complete fairing. I have traced the Y/W wire -- as mentioned before, I used it to perform the gauge test; I cannot follow it to the sensor, itself, no idea where to attach a ground wire on the sensor assembly. Can anyone shed some light on this problem?


We were supposed to leave for three days, tomorrow, but I don't care to ride it without seeing the temp gauge showing me what the engine is doing. Not certain the fan switch is working, either, so knowing the coolant temperature is critical, as always. Cheers!

[debron]

I grounded mine last year and it's worked fine ever since. As I recall, whether the fairing is on or off is irrelevant but you do need to take the faux-tank cover off. What you need to do is run a new wire from one of the mounting bolts to a good ground (I ran it to the negative battery terminal.) It's down the right hand side, a little awkward to reach but not impossible. I think it took an 8mm wrench. I'll try to get a photo tomorrow but in the meantime, here's a drawing from the manual:

[SgtSlag]

OK. That helps a bit. I hope this cures my problem. I'm learning -- to really despise the FSM. This bike is fantastic when it works, and a ... when
it fails. Cheers!

[debron]

PS - You will also need to remove the battery and battery tray. Looking down the right side you should be able to see the temp-sensor housing. Skinny forearms and small hands helps reach it! I used a crimp-type fork terminal and some black wire and slipped the terminal under the bolt head the re-tightened.

[doug of so fla]

In the drwg above the sensor is right above the bottom of the green circle and the wire to it has a bullet connection which comes loose and creates a bad connection. Check that also, usually is loose , recrimp it so it fits tight. You can follow the wire from that and on the other end of it (inside fairing) Is another bullet type connector that can be loose also. Do those and run a new ground wire from frame or battery to the bolt shown in drwg or somewhere on the waterpump. (the bolt shown sometimes is very tight and you do not want to break it). The t-stat does not have a good ground because it is mounted with rubber hoses. I and others use a digital temp gauge (AC tech gauge from Harbor FRT $6.00, it works perfect, I stick it down between alt cover and engine. http://amervoyassoc.org/forum/viewtopic.php?f=15&t=4669 see 6th post down.. Have a good trip and ride safe..

[SgtSlag]

Life got in the way of my fixing the bike, until yesterday. I went to Harbor Freight and bought a 12", straight, Hemostat. That allowed me to push the plug on the sensor tip, finally. For anyone else who has difficulty in re-seating this wire, buy yourself a 10"-12" Hemostat, but get the curved unit, instead of the straight. It will likely be easier as the tip of the transducer is pointing downwards, and the curved jaws will give you a better angle than the straight jawed Hemostat I used. The cost of the Hemostat was $5.98 + tax. Cheers!

[ccannon]

Does anyone know what color the temp sensor wire that comes unplugged is? I can't seem to locate it. Any pictures of the process would be super useful as well.

[debron]

Does anyone know what color the temp sensor wire that comes unplugged is? I can't seem to locate it. Any pictures of the process would be super useful as well.

Per the wiring diagram it is Y/W, presumably yellow/white. I'm stretching here but I think that means a yellow wire with a white stripe. Anyone else??

[doug of so fla]

Does anyone know what color the temp sensor wire that comes unplugged is? I can't seem to locate it. Any pictures of the process would be super useful as well.

Read the posts above: The drwg shows you the sensor, Debron tells you how to get to see it. The ground you need to create is because the T-stat hsg is suspended by rubber coolant hoses so the sensor mounted in the hsg is not getting a very good ground, so you are running a wire from the t-stat itself to a good ground, battery ground or to a place on the metal frame of the XII,that is creating a better ground. The bullet connector shown at the bottom of the green circle is in a position that because it is just hanging down from the end of the sensor it vibrates and becomes loose.. You need to squeeze it to get it to connect on the sensor tight.

[ccannon]

Thank you guys for your concise responses. I will fix the ground and re-crimp the connector and hopefully that will solve my problem. :)

On a related note, is water pump replacement something that that is part of standard maintenance?

[doug of so fla]

The water pump should last 100,000mi + but if you put more than 3qt, 22oz of oil in the engine, the seal in the water pump may be swimming in oil and come loose on the shaft and then it needs to be replaced. Once replaced with the proper seal and installed correctly, pushed all the way down in the pump, it should last a very long time. again with the proper amt of oil in the engine. Just in case someone does not know the XII has 2 drain plugs and the filter to remove ALL the oil out of it.

[ccannon]

The water pump should last 100,000mi + but if you put more than 3qt, 22oz of oil in the engine, the seal in the water pump may be swimming in oil and come loose on the shaft and then it needs to be replaced. Once replaced with the proper seal and installed correctly, pushed all the way down in the pump, it should last a very long time. again with the proper amt of oil in the engine. Just in case someone does not know the XII has 2 drain plugs and the filter to remove ALL the oil out of it.

Good to know, thanks.

[Muleears]

I know with improper ground the gauge won't work correctly, but how does it not work correctly? I know it can show a low reading, but how low? My bike (20K mi.) never has a reading above 1/4 of the temp. gauge. Seems low to me but I don't know if that's the normal running temp or the gauge reading too low. Any help?

[Steve do]

There is 3 bars from the C mark, the third one is bold, mine goes 1 1/2 bar above it going down the road. If I set at a light very long it might get to the third bar above the bold one, cools back down as soon as I start moving. Don't know what that reading is, but it has never got near the red mark. This is what my 88 and 03 models have done. Good Luck.

[doug of so fla]

I have never liked bar gauges they tell you nothing. Harbor freight has a digital A/C thermometer that you can touch it to any part of the XII and get proper temp. $6.00, They also have a infra one that you can point at anywhere and get temp for about $10.00, I have the A/C temp one stuck down between the engine block and alternator cover and gives me exact temp of engine at anytime I want. Just turn it on when you want and then off.

http://i60.tinypic.com/2yo2zjq.jpg[/

[Steve do]

You know somebody's going to ask,,,, 858F.

[doug of so fla]

You know somebody's going to ask,,,, 858F.

85.8 (F) degrees fahrenheit, was temp when I took photo in my garage, push other button it will read (C) degrees celsius. You can't see the decmil point from the angle I took photo.