Reserve fuel sensor 37810-MN5-008

Janko · Aug 6, 2017

Hi

My fuel reserve light failed and I need replacement but part is not available
did you guys have any solution for this problem?

dwalby · Aug 6, 2017

Are you sure its the sensor that failed, and not a burned out bulb? If the part is unavailable then you're left with Ebay, but I didn't see any hits on that part number.

Upt' North · Aug 7, 2017

If it's part No. 20 on the parts list I think it's available from CMS in the Netherlands.
Hope it helps. If not it looks as though pretty much all small tank parts are available.
Upt'North.

Dale_I · Aug 7, 2017

Try to send a PM to OKBobW. He is local to me and I would bet anything he has a couple. Work out a price with him and payment.

If he doesn't seem willing to ship, let me know. I can run over and grab it from him. It would give me an excuse to visit with him and that is never a bad thing.

Anyway, I would be willing to ship. I do it everyday in my work. If payment is an issue, shoot me a PayPal and I can take cash over to him.

If he isn't monitoring his PM's from this site (ie: doesn't answer in a day or two) let me know. I can try and shoot him a text or give him a call.

the_gr8t_waldo · Aug 7, 2017

before you buy anything, check the red connection for the sensor. it's on the left side and about at the rider's knee. once the plastics are away you can check with a meter. It's much easier to get to rather than the dash assembly.

Norm · Aug 7, 2017

In a hurry so may have miss if this is 1100 or 1300?

Can't remember if 1300 is same as 1100?

1100 sensor is a thermistor which seems to become "waterlogged". Two remedies :

1) Disconnect the wires from the fuel tank, and remove the fuel pump unit from the fuel tank. Connect a #194 bulb or test light with that wattage of bulb, from the sensor connection on the pump unit to battery positive and leave it for several hours. In other words: the test light goes from the tank unit to the battery. It doesn't have to be the bike's battery, any 12 volt battery will do. The battery negative is connected to the ground spade lug on the pump unit or anywhere onto the metal. If the bulb begins to glow, leave it until the bulb has been to full brightness for 1/2 hour or so. That usually "dries out" the thermistor which will usually work just fine for years, again. This seems to happen on bikes which don't have the fuel level run down often enough to place the thermistor out of the fuel.

2) Thermistors are available & I usually buy them from Mouser. The same thermistor works for many bikes of for making fuel level indicators.

Mouser Electronics: P/N: RL2004- 582- 97- DL
Desc: .22 1k Ohm RoHS noncompliant
GE Sensing Thermistors - NTC

They are a few dollars in packs of (4)

If not clear, tag me and will try to explain better.

Janko · Aug 8, 2017

Yes, I'm sure it is sensor, as soon I'm grounding wire on the top of the tank light goes ON

Norm · Aug 8, 2017

That's a simple fix, IME.

Try using a #194 bulb in series with the sensor connection on the pump and a 12 volt battery. I usually pull the pump to do the job on the bench, but suppose that one could simply siphon the fuel level below the thermistor. I may have done it that way but can't say for sure. Regardless, it's simply a matter of "drying out" the thermistor, IME.

Leave it hooked up for several hours and that will usually do the job. If memory serves, some have sat on the bench over night and the light was bright in the morning. I can't recall the longest time needed but they, usually, eventually dry out and work fine for years. Otherwise, the thermistor isn't difficult to replace since it's under a little metal hood on the side of the pump support. I seem to have lost a bunch of my photos in a Dropbox disaster so hoping they can be recovered. If I find them before you reply with success, I'll post.

Janko said:
Yes, I'm sure it is sensor, as soon I'm grounding wire on the top of the tank light goes ON

Janko · Aug 8, 2017

Dale_I said:
Try to send a PM to OKBobW. He is local to me and I would bet anything he has a couple. Work out a price with him and payment.

If he doesn't seem willing to ship, let me know. I can run over and grab it from him. It would give me an excuse to visit with him and that is never a bad thing.

Anyway, I would be willing to ship. I do it everyday in my work. If payment is an issue, shoot me a PayPal and I can take cash over to him.

If he isn't monitoring his PM's from this site (ie: doesn't answer in a day or two) let me know. I can try and shoot him a text or give him a call.

Hi Dale is send him PM, thanks a lot

Janko · Aug 8, 2017

Thanks to all for support

Janko · Aug 8, 2017

Hi Norm

Can you explain better option #1, I would like to do it but not 100% sure how to connect or better say dry it out, Thanks
The best wold be if you can send some drawing and it is 1994 ST1100

Norm said:
In a hurry so may have miss if this is 1100 or 1300?

Can't remember if 1300 is same as 1100?

1100 sensor is a thermistor which seems to become "waterlogged". Two remedies :

1) Disconnect the wires from the fuel tank, and remove the fuel pump unit from the fuel tank. Connect a #194 bulb or test light with that wattage of bulb, from the sensor connection on the pump unit to battery positive and leave it for several hours. In other words: the test light goes from the tank unit to the battery. It doesn't have to be the bike's battery, any 12 volt battery will do. The battery negative is connected to the ground spade lug on the pump unit or anywhere onto the metal. If the bulb begins to glow, leave it until the bulb has been to full brightness for 1/2 hour or so. That usually "dries out" the thermistor which will usually work just fine for years, again. This seems to happen on bikes which don't have the fuel level run down often enough to place the thermistor out of the fuel.

2) Thermistors are available & I usually buy them from Mouser. The same thermistor works for many bikes of for making fuel level indicators.

Mouser Electronics: P/N: RL2004- 582- 97- DL
Desc: .22 1k Ohm RoHS noncompliant
GE Sensing Thermistors - NTC

They are a few dollars in packs of (4)

If not clear, tag me and will try to explain better.

Reserve fuel sensor 37810-MN5-008

Incorrigible Idealist