You DO NOT have to remove the tank, or remove the TB's to replace this unit (unless your a Honda shop trying to charge folks flat rate labor rates)Yikes! Tank and TB off it appears
Temperature gauge reading
- Thread starter Huntly
- Start date
OP
OP
Well now I know where it is that's a start not I five minute job (is there such a thing) some thing to keep me busy now the nights are drawing inThe ECT sensor wiring is one of the more commonly found damaged wires on these bikes.
Either by Heat (wires get crispy and the coating crumbles off exposing the wires to short out) or by folks trying to remove the T-stat, or tighten all the leaking clamps and twisting the T-stat housing to get at the clamps, thus causing the wire coating to crumble off etc.
Another sure fire way to damage these three wires is by trying to remove the T-stat cover WITHOUT propping a socket or piece of wood underneath the T-stat housing for support, and twisting the housing and hoses.
Problem is nobody ever looks behind the T-stat housing to check for damage in this area.
In the past 14 years or so, I've never found a damaged/bad ECT sensor terminal or switch, but I have found damaged wires, shorting out by touching each other more often than I'd care to admit.
I'm guessing your gonna find something like this behind the terminal connector....
OP
OP
So can you see it when you tilt the tank forward or do you have to take the airbox off
Not sure what you mean “tilt the tank forward”
But if you haven’t worked in this area before, the easiest would be to remove the tank (have a new fuel joint hose in hand) and remove the radiator etc.
You would then be able to lift the rubber sheet and see it.
However, if you find it looking like the one in my picture, there would be nothing to do but order the sub wire harness and replace the whole unit.
And for that you would need to remove the Tupperware.
But if you haven’t worked in this area before, the easiest would be to remove the tank (have a new fuel joint hose in hand) and remove the radiator etc.
You would then be able to lift the rubber sheet and see it.
However, if you find it looking like the one in my picture, there would be nothing to do but order the sub wire harness and replace the whole unit.
And for that you would need to remove the Tupperware.
Depending on what your more comfortable doing (lifting tank-removing air box base) or (removing radiator), if you just want to see if the wires are damaged, you could go in through the front (behind radiator) with a mirror and flashlight.
Sorry, just shared what the service manual shows 
OP
OP
Igofar do you have to completly remove the rad or just move it forward I've looked at the parts list but I cant see the sub assembly. Just a thought is it worth replacing the thermoset whilst in in there
You can just pivot it forward so not necessary but take time to look it over real good.
www.st-owners.com
Here the rad was removed:
Article [13] - ST1300 - 1st Significant Service: Coolant, Thermostat, Starter Valve Synch, & Other | ST1300 Articles
I completed some needed maintenance on the '04 ST this weekend, after 11.3k miles. This was my first time with all the fairing removed and tank+airbox removed, and getting it disassembled & reassembled properly seemed as significant as the actual maintenance! I found lots of good information...
Here the rad was removed:
OP
OP
Do you know the part number for the harness?
Throttle body sub-harness (if replacing it) 32103-MCS-770
Article [13] - ST1300 - Throttle Body Removal/Sub-harness Replacement | ST1300 Articles
Throttle Body Removal and Sub-harness replacement In all of the procedures below follow the detail steps in the Service Manual. This documentation discusses only those items that are not in the SM or not covered adequately. If at all possible, ride the bike until the last segment of...
OP
OP
Is it a nightmare to replace josh or could I get away with insulating tapeThrottle body sub-harness (if replacing it) 32103-MCS-770
Article [13] - ST1300 - Throttle Body Removal/Sub-harness Replacement | ST1300 Articles
Throttle Body Removal and Sub-harness replacement In all of the procedures below follow the detail steps in the Service Manual. This documentation discusses only those items that are not in the SM or not covered adequately. If at all possible, ride the bike until the last segment of...
It looks quite involved. But if you aren't able to solder the wiring back together, I'd say that's the best option available. But personally, I've never had this issue or replaced that harness.
OP
OP
I got in contacted with the main UK Honda dealer to see if they had that sub wiring assembly no such luckThe ECT sensor wiring is one of the more commonly found damaged wires on these bikes.
Either by Heat (wires get crispy and the coating crumbles off exposing the wires to short out) or by folks trying to remove the T-stat, or tighten all the leaking clamps and twisting the T-stat housing to get at the clamps, thus causing the wire coating to crumble off etc.
Another sure fire way to damage these three wires is by trying to remove the T-stat cover WITHOUT propping a socket or piece of wood underneath the T-stat housing for support, and twisting the housing and hoses.
Problem is nobody ever looks behind the T-stat housing to check for damage in this area.
In the past 14 years or so, I've never found a damaged/bad ECT sensor terminal or switch, but I have found damaged wires, shorting out by touching each other more often than I'd care to admit.
I'm guessing your gonna find something like this behind the terminal connector....
OP
OP
Igofar you've done this task a few times does the petrol tank need to be removed ofr just propped up
It’s been a long time but I recall the sensor is tapped into the back half of the thermostat housing. The service manual details coming to it from above but like Larry says it’s far easier to drain the coolant then remove the radiator and the cross member behind it and remove the thermostat housing from the front. After the fairing is removed it’s a one hour job to have the thermostat housing out.
I have a step by step pdf with pictures & text detailing thermostat removal. PM me an email address and I’ll send the coolant & t-stat replacement tutorial.
I have a step by step pdf with pictures & text detailing thermostat removal. PM me an email address and I’ll send the coolant & t-stat replacement tutorial.
Either way will work.
To remove the tank is just 3 bolts, and a couple electrical connectors that are out in the open.
Or you can simply lift it up to remove what you need to get to.
OP
OP
Finally got the bike back from the shop £400 lighter. In the end it was the thermostat but every thing gave a fight which is why the price was so high a few sheared bolts and crumbling jubilee clips along the way didn't help so if your in the UK treat your self to a fender extender to reduce the tin Worm