ST1100 Low Fuel Sensor Repair
There are several articles in regards to repairing the low fuel sensor on Honda Goldwings and V-65's on the internet.
The ST1100 uses almost the exact same setup and therefor these articles can be used to also repair the ST1100.
Taken from GWRRA Message Board Achieves ( February 2002):http://archive.gwrra.org/board/messages/16691/13979.html?1013928537
The V-65 low fuel sensor has a little canister that's soldered to a threaded
plug with a Bakelite insulator in the center. I carefully desoldered the
canister and the center conductor from the threaded plug. Then I removed the
fuel pump assembly from the Gold Wing's fuel tank. I removed the screw from the
electrical connector near the top of the fuel pump mounting bracket and the
two screws that hold the sensor assembly to the lower part of the pump assembly,
just above the pump. I desoldered the old sensor from the little screw-on
bracket and cut the wire about 3/8" from the top of the sensor. I stripped about
1/8" of insulation from the wire that I cut and tinned the bare wire with
solder. Then I soldered the wire to the replacement sensor and tack-soldered the
replacement sensor to the little screw-on bracket. I soldered the tinned end of
the wire to the center terminal of the replacement sensor.
I decided to run another dynamic test on the rebuilt sensor assembly. It passed
both static (ohmmeter) and dynamic tests. Then I mounted the rebuilt sensor to
the fuel pump assembly and reinstalled the fuel pump assembly to the Gold Wing.
I still had a slight doubt whether this repair would be successful, so I drained
the fuel tank down to a little over a gallon. I took the Gold Wing for a road
test, and just as the needle on the gauge lined up with the red mark, the
indicator light started coming on! Now I was satisfied that the repair job was a
success! I learned that with a little soldering skill, I could use a Honda V-65
Magna low fuel sensor, Honda part no. 37810-MB4-008 for a Honda GL 1500 low fuel
sensor, which has NO HONDA PART NUMBER and save myself about $200.00!
If your GL 1500 Gold Wing is still under warranty and your reserve indicator
malfunctions, take the Gold Wing to your Honda Dealer and they'll probably
replace your fuel pump free from charge. But, if your GL 1500 is not covered by
the warranty any more, you too can save a few dollars by buying a V-65 Magna
sensor (for about $48.03) and, with a little soldering skill, fix it yourself!
By Howard Halasc on Saturday, February 16, 2002 - 5:45 pm
In the May issue of Wing World Magazine, I tried to explain how to save money to
get a malfunctioning reserve indicator working again without spending a lot of
money for a new fuel pump on the GL 1500 Gold Wings.
One problem is that most Honda dealers don't stock the V 65 Magna sensor and
most salvage yards don't have any good ones that haven't corroded or gone bad
from soaking in old spoiled gasoline.
After doing a little bit of research, I found out that the sensor is actually a
thermistor that is rated at 1,000 ohms at 25 degrees Celsius. These little
thermistors come in two different types-PTC and NTC. What our Gold Wings use is
the NTC, which decreases resistance as temperature increases. It is in a series
circuit with the indicator bulb. As long as the thermistor is submerged in
gasoline, it remains cool and the resistance to the flow of electrons is
anywhere between 900 and 1200 ohms, depending on the temperature of the
gasoline. When the gasoline level drops below the level of the thermistor, the
current flow through the thermistor and the light bulb causes the thermistor to
heat up and drop its resistance, thus illuminating the bulb. Damage to the
thermistor is likely to occur if you refuel with the ignition key on and the
reserve indicator illuminated. When the cold fuel comes in contact with a hot
thermistor, the sudden temperature change permanently damages the thermistor.
My advice is to turn your key to the off position when you refuel. This advice
applies to all motorcycles, not just Gold Wings.
The article in the May issue of Wing World also applies to the GL 1200
Interstates and Aspencades. Here again, there's no Honda part number for the
reserve indicator sensor and the sensor is part of the fuel level sending unit
on the GL 1200I's and GL 1200A's.
At one time, Radio Shack sold various thermistors, but the last time I checked,
they told me that they no longer stock them. I bought some from Ace Electronics
here in Houston and they cost $1.00 each. The V65 Magna sensors can be repaired
by installing a new thermistor in the little canister, but the GL 1500
canisters are sealed and difficult to open up for thermistor replacement. By the way, I wrote articles about
this topic and they appeared in the May and July 1998 issues of Wing World. Howard Halasz, WING WORLD contributing editor
Taken from: http://duaneduncan.com/low%20fuel%20sensor.html
The low fuel sensor...p/n 37810-MN5-008...or can use the one from a V65 Magna...p/n 37810-MB4-008..
The part number for the 1200 and 1500 low fuel sensor is 37810-MN5-008. They are $30.11
Note that this is the Honda part number, the other one is available from elec supply house.
I use the same thermistor in the GL1200 and the GL1500. The low "fuel sensor" is a NTC THERMISTOR. www.newark.com
Part number 20F735 TYPE RL2004-582-97-T10 $2.82 If you are in the US call 1-800-463-9275.
If You are in CANADA, email me and I will find the canadian phone number.
The thermistor is in a little can about the size of your finger. It is soldered to a wire on one end and to the can on the other. Some guys cut the can open but I have been drilling out the spot welds and pushing the can back together. I then punch it in 3 places to hold it together. From talking with others, I find that the can is not the same on all models. It is pretty simple stuff anyway. You are not really adapting anything. It is physically almost identical to the part used by Honda. Electronically, it is identical. Just carefully bend the leads and cut to length to match the original. Hold the leads with small needle nose pliers close to the thermistor so as not to fracture it while bending.
( 1 K ohm ) thermistors on-line from Mouser Electronics ( http://www.mouser.com
) for $5.80 plus
$3.67 shipping + handling for a total of $9.47 or about $1.89 each.
The part number is: 527-2004-1k or a link to the data sheet is:http://www.mouser.com/search/ProductDetail.aspx?R=RL2004-582-97-D1virtualkey52710000virtualkey527-2004-1K
Contributed by: Tom Melnik, STOC @346
Pictures provided by Carroll Walker. Fuel system wiring schematic provided by Tom Melnik. fuel system wiring