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1Back to top Go down   Heated Grip Fix Empty Heated Grip Fix Mon Feb 03, 2014 11:28 am

Born Again Eccentric

Born Again Eccentric
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One of my projects over the weekend was to get the right hand (throttle) heated grip working. It's not that cold in the UK at the moment, but cold enough to notice the lack of workingness. Following advice on this forum, I removed the entire front fairing and fuel tank (easier said than done, especially with the additional fuel level and temperature indication dashboard, and the radio fitted into the left hand glove box) so that I could access the wiring connectors. A continuity check proved that there was a break in the right hand grip circuit (the resistance of the left hand grip was about 8.2 ohms).

Removal of the bar end weight from the end of the right handle bar immediately revealed that both wires (threaded up in the inside of the handle bar tube) had broken off at the joint with the heating element and seemingly it was unrepairable. On the basis that nothing is impossible, I managed to roll back the rubber grip about 10 - 15mm (this grip is necessarily a very tight fit on the heating element, which in turn appears to be bonded to the throttle assembly). I secured the rubber grip in place with a tie-wrap. I then was able to carefully peel back the exposed surface layer of the heating element insulation. Doing this revealed that the junction between the wires and the heating element wires was actually about 20 - 30mm inside the insulation (Fig 1). 

With the wire break having occurred on the outside edge of the insulation (either through mechanical wear or someones previous attempt to remove the throttle assembly), it was then a simple matter of feeding/pulling a little more wire through the handle bars and soldering them onto the stubs of wire remaining attached to the heating element wire (Fig 2). Fortunately, there is some cable slack under the fuel tank that will allow this - it is also easier to achieve if you also unbolt the ignition switch module to be able to gain access the cable entry point in the front centre of the handlebars. The job was completed by wrapping the exposed wires with insulation tape (with hindsight, sliding an insulating sleeve onto the cable before soldering the joint would have been a tidier solution) and then securing the whole repair in place with a couple of turns of insulating tape before allowing the rubber grip to return to its normal position. A final continuity check at the connector under the fuel tank proved that the heating element was back in the circuit and reading approx 8.2 ohms on both heated grips. Ensuring that the heated grip cable was in the correct slot in the throttle assembly and that the throttle had a full range of movement, the bar end weight was then replaced.

Heated Grip Fix Application                                                          Heated Grip Fix Application
Fig 1: Broken cable pulled through and cable under insulation  Fig 2: Soldered repair (before wrapping in insulation tape)

With the fuel tank and fairing re-instated, a test ride proved that both heated grips were fully functional again (this could have been done statically - but after several hours of working on the bike, the test ride was as much a reward for me as it was an it-has-all-gone-back-together-and-is-working-properly check.

Lessons Learnt: 
1. If pushed for time, start at the bar end weight end and potentially avoid a lot of work - if the fault is as obvious as mine was, then there may not be a need to remove the fairing and fuel tank. (If only the fuel hose connectors were accessible without removing the upper fairing - then the fuel tank would come off more easily!). The electrical tests could be done from the bar end position (check for continuity and voltage supply).
2 Slide an insulating sleeve up the wire before soldering the joint - once the soldering is complete, slide it down and over the repair - much easier than fiddling around with thin strips of insulating tape trying to wrap each wire individually.

    

2Back to top Go down   Heated Grip Fix Empty Re: Heated Grip Fix Mon Feb 03, 2014 2:44 pm

92KK 84WW Olaf

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Paul wrote: Lessons Learnt: 
1. If pushed for time, start at the bar end weight end and potentially avoid a lot of work - if the fault is as obvious as mine was, then there may not be a need to remove the fairing and fuel tank. (If only the fuel hose connectors were accessible without removing the upper fairing - then the fuel tank would come off more easily!). The electrical tests could be done from the bar end position (check for continuity and voltage supply).

Lots of posts here from me on this one. I replaced all the connections on the LT to allow the tank to be removed without removing any fairing. The electrical connections were at the rear of the tank by my right knee, accessed by removing the right side panel. I replaced the two fuel hose connections so that they could be accessed through the side vent slots to loosen and retighten them. By opening those and disconnecting the electrical wires I was able to move the tank back and lift it clear. By lengthening the fuel pipes I could lift the tank back enough to access the coolant fill without disconnecting anything, just remove right hand storage box and panel under for access. These fuel pipes perish and you would be well advised to change them. The inside one is harder to get at as its between the airbox and intake manifolds. Just make sure the worm drive clips are placed so you can access them easily with the fairing on.

My RT is slightly different in that the electrical connection is front left of the tank, I can still access it. I have to remove right hand pocket and fairing inner as the tank wont lift clear without fouling the fairing. But thats it.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 37,190 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 42,640 miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

3Back to top Go down   Heated Grip Fix Empty Re: Heated Grip Fix Mon Feb 03, 2014 3:55 pm

Born Again Eccentric

Born Again Eccentric
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Great advice - next time I have to take the fairing off, I will make sure that I have some spare fuel hose so that I can make the modifications and will look at accessing through the fairing vents. I thought about this (briefly) but was concerned that by lengthening the two fuel hoses I would end up getting a kink in them when the tank was in its normal position.

Based on my tyre concerns with ageing rubber (separate post), I think replacing these safety critical hoses might just become a priority!

    

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