Triumphrat

RexxyPup · 10-11-2008

Just when I thought I could relax into just riding again, another minor niggle has appeared.

I pulled to a stop at traffic lights this morning and by the time the lights turned green, I had noticed that my temperature gauge had just hit the edge of the red.

Turned for home, and as long as I kept moving I could keep it in its normal place (1/4" above top of cold). As soon as I stopped it would start rising, and not stop at its normal hot with fan on position (mid way on gauge).

On nursing it home I check that I had enought coolant (It was full when I did the pre-ride checks) and it was at mid point on expansion tank.

With my helmet off it became clear that the fan wasn't running. At least that explained why the temp at the lights.

So I checked the 15A fuse (and the spare that is in the next slot

). The fuse was fine.

Right, so fan not running and fuse okay. My electrics knowledge is not the best (as you know) but if I remember correctly, a fan draws maximum current at start (zero revs) so I am thinking that if the fan were jammed that the fuse would have popped. A quick hand in the right fairing confirms the fan moves freely.

So does the bike have a separate sensor to switch the fan, or is it switched via the ECU? I'm starting to think this is a switch or power issue.

I guess it is main fairings off time. Could someone help on how to troubleshoot this please, as the workshop manual appears to be no help at all on this one!

Second question.... would I have done any lasting damage when the temperature hit the red? What sort of thing should I check for?

Thanks in advance..

A concerned Rexx

rminchi · 10-13-2008

2 days and no responses? I'll toss my 2p in. On my '99 there's a temperature sensor on the left side of the radiator that runs the fan. These tend to fail (on all types of vehicles) after several years as well as the wiring going to it. Since I don't have a wiring diagram handy, I don't know if the sensor works on a ground or hot lead. I'd check to see if the sensor is stuck open by checking with a ohm meter both cold and run until it gets hot enough where the fan would normally start. When cold, the meter should not show any reading at all (infinite) and when hot it should show nearly 0 ohms. Getting the fairing off is probably more work than anything.

As far as doing damage, unless you kept running it with the needle in the red for > 5-10 minutes I wouldn't worry about it. Not ideal, but usually not a problem.

Rob

johnny · 10-13-2008

Take a pair of jumper wires (one fused for power side) and direct connect fan to batt or acc. If fan runs then your problem may lie with the temp sensor (that tells the fan its time to come on). From there perform test of temp switch.

redmosquito1 · 10-13-2008

after jumpering to test the fan you could install a switch and hard wire the fan to the battery through a 15A fuse. That way you save a little cash on the sensor and you have full control of when your fan is running and when its not. We did this on my bros gsxr and it works beautifully.

oldndumb · 10-13-2008

Forget comparing this system to an old automobile. The fan does not actuate from a temp sensor. The ecu determines when it is supposed to run.

I agree that you can hot wire the fan motor to test it, but I would hesitate to permanently wire it that way, until someone that has a schematic of the ecu can tell you if that is acceptable. It goes without saying that it must be isolated from the ecu before performing the hot wire test.

Before someone mentions the fan relay, that did not come about until 05.

Calliway · 10-13-2008

Even if the ecu triggers the fan the ecu still needs to know what temperature the bike is so there must be a coolant temp sensor on the bike. If that is faulty then the fan wouldnt come on but I would also assume that it would trigger an error code as well.

http://www.bikebandit.com/triumph-mo...-2002/o/m17603

Line number 11 on the fiche.

oldndumb · 10-13-2008

Sure it has a temp sensor. My concern was that the fan is not connected to the sensor. The fan is connected to the ecu, as is the temp sensor.

Out of caution, I would not be wiring the fan direct until someone with knowledge of the ecu circuitry and logic approved it.

I could be totally over cautious on this, but my concern is that a smoked ecu would really upset your day.

I would not be as concerned if we were talking about a +05, since the ecu is triggering the relay and the fan is not connected to the ecu.

Calliway · 10-13-2008

Yes youa re absolutley right with your last comment OnD. I to would be concerned about jumping any wires connected to the ecu.

My only point was that if the ecu doesnt know what temp the bike is then it wont switch the fan on and since the source of that data is the coolant temp sensor then it might be a good idea to start there.

It should be a two pronged unit and something that you can test with the bike at running temperature but heed OnD's warning. I might of come across like what he was saying was irrelavent which was not my intention.

oldndumb · 10-13-2008

No problem on this end. I understood your point.

Standard method of testing the temp sensor is take resistance readings.

Warm engine - 200-400 Ohms

Cold engine
20 C 2.35-2.65 K Ohms
10 C 3.6-4.0 K Ohms
0 C 5.6-6.25 K Ohms

CLB · 10-13-2008

Rexx,

You probably have a fan relay, I can't imagine sourcing fan current from the ECU.

It's probably the same part number as your headlight relay. Pull them both and check.
If they are the same... swap them for a check.