Triumph Rat Motorcycle Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter #1
I recently purchased a used Thunderbird. It had some questionable mods done, including a-hole pipes. These were Emgo 12" chrome glass packs mounted to the end of the head pipes. This required cutting off the flanges for attaching to the catalytic converter. The bike didn't come with any of the original parts. To be honest, I liked how they looked, but they were obscenely loud. At least they sounded bad too. ;)
It also had the wide beach bars and really long risers. I managed to find everything on ebay. Used but very good condition headers, cat, and mufflers. Also the correct risers and factory bars. I did the bars first, then the exhaust and finally the risers. At some point between the pipes and risers a fault in the front wheel ABS sensor circuit appeared. I have attempted to find anything that I may have done near the bars and there is nothing jumping out at me. The connector in in the head light bucket and the wires disappear into the harness and go under the tank, nothing looks out of place.
My sensor does show open if I put a multi-meter across the pins, but I don't know if this is normal. An e-bay sensor didn't seem to fix my issue.
I can clear the code with tune ecu but it comes right back and the ABS light never goes out.
Does anyone know if there is a hidden connector for that circuit between the head light and the ABS pump?
Can someone with ABS test their sensor with a multimeter and let me know if they get a resistance value?
Thanks in advance.
 

·
Registered
Joined
·
42 Posts
Have you Googled "how to test a hall effect"? Looks like you can test the sensor with a voltmeter without disconnecting them from the circuit.
My service manual electrical schematic shows the front and rear sensors as two wire devices that plug directly into the module. I don't know how many connectors are hidden under the tank.
 

·
Registered
Joined
·
1,593 Posts
You didn't say if you went for a ride after reassembly. The ABS light will be on at startup until you get the bike rolling for at least a bit.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #4 (Edited)
I connected the ebay sensor to the connector in the headlight bucket.
I powered on the bike, connected to the ecu via tuneecu.
From there I queried the ABS module, it still showed the open/short code for the front sensor.
I cleared the code, powered the bike off then back on again and queried the ABS modue.
The same code is still present.
The service manual says that you measure the mA load of the sensor to test it. I would think that means that it is a resistive load but both are showing infinite resistance on the 2k and 20k scales. The internet says that 2 wire sensors should have a resistance of 2k to 10k ohms. I can't find any specific testing information (excepting the service manual) on the Triumph sensors so this is all best guess.
Brand new sensors are $140 on that bandit site that sells bike parts. I was hoping that someone else had this problem or that we would find that the sensors are kind of problematic. I might spring for one more ebay sensor or just bite the bullet and do a new one but I would really like to know definitively that the sensor is the problem.

I am in Denver so lots of snow the last couple of days. When the weather clears enough, I will pull the exhaust and double check that I didn't pinch a wire somewhere.
It looks like the harness runs down the spine of the bike so I think that is unlikely.
I did temporarily relocate the voltage regulator/rectifier. The a-hole pipe on the left side of the bike was yelling directly at it. The RR was actually fuzzy with soot.The rear sensor harness runs through that location but it isn't throwing a code, so I am pretty sure I didn't damage it.
Everything has since been returned to stock. I like stock.
 

·
Registered
Joined
·
714 Posts
Simplest way would be to compare any measurements with the known good sensor on the rear.
not sure where the connectors are but is it possible to swap them over to prove the sensor.
The manual only gives a typical mA load reading for a good sensor so not sure if it's possible to do a passive test reading resistance, on others you could read a small AC voltage when you spin the wheel but again not sure if that works with these sensors, you've got the advantage of having one good sensor on the rear so use that as your reference.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #6
I feel like a moron for not having considered using the rear sensor as a control. I will post an update when I get back to it.
 
1 - 6 of 6 Posts
Top