Speedo needle dead, P1500 error code, odometer works fine

[TURBO200R4]

They do go bad
Water sometimes gets into it and corodes.

 

[CrzystghndKC]

There is a place here in Kansas City that repairs speedometers and Tachometers if you can't find someone local to you.

 

[ChrisACT]

Thanks guys.

 

[ChrisACT]

Pulled the speedo apart. They're really not designed to be pulled apart. So if it wasn't stuffed before, it sure is now.

It's a multi-layer circuit board with mostly surface mount components. I can't see any corrosion or damaged components in there but it's all so tiny that it'd be next to impossible to know for sure.

Even if I can get the error code to go away, the speedo needle still doesn't move but the odometer is ticking over as are the trip meters. So it's getting a signal. I've confirmed that with the scope too.

Looks like I'm going with the Acewell gauge now. Time to join the old harness with the new one.

 

[ChrisACT]

... which means installing a water temp sender in the upper radiator hose.

Can anyone tell me what the internal diameter on that hose is at the radiator end? It looks like it'd be somewhere between 20mm and 24mm. I need to order the water temp sensor tube for the Acewell speedo.

Water Temp sensor tube – Acewell Australia

They do them in 20, 22, 24 and 26mm so one will fit. Question is ... which one?

If nobody knows, I'll just pull it apart and work it out but just thought I'd ask in case it's in someone's head already. Saves me pulling it apart, then waiting days before I have the part to put it back together again.

Thanks.

 

[Gregger]

If you aren't going to use the existing high water temp sensor any more (because it's a simple on/off temp switch), why not install the new linear one there? Need to verify thread size though which might be a pain. That in-hose adapter is a pretty simple install though.

Oh, don't know the hose size... sorry.

 

[ChrisACT]

The existing water temp sender would be used by the ECU for cold start (I'd presume). So I can't disconnect it from the ECU or remove it from the engine.

I believe the temp signal from the ECU to the instrument cluster is just an on/off (over temp) indicator so that's no good for the new gauge as it shows a digital readout of the coolant temp and therefore needs to see the temp sender itself.

The Acewell gauge measures resistance on the temp sender so I can't just piggy back it off the existing Triumph sensor either as the ECU will be putting it's own voltage across it.

 

[Gregger]

The existing water temp sender would be used by the ECU for cold start (I'd presume). So I can't disconnect it from the ECU or remove it from the engine.

I believe the temp signal from the ECU to the instrument cluster is just an on/off (over temp) indicator so that's no good for the new gauge as it shows a digital readout of the coolant temp and therefore needs to see the temp sender itself.

The Acewell gauge measures resistance on the temp sender so I can't just piggy back it off the existing Triumph sensor either as the ECU will be putting it's own voltage across it.

@ChrisACT you are 100% right. My bad. I should have looked at the prints first before passing on that assumption of how a typical coolant temp sensor circuit works. Checking the prints, the ECM does appear to monitor feedback from that sensor as you stated. Learned something. Let us know how it goes and pics always appreciated.

 

[ChrisACT]

I found an eBay listing for the water temp joint pipe that said 22mm was compatible with the Rocket. So I've ordered one of those. Should arrive in a couple of days. In the meantime, I'm working on the harness.

I've cut the ends off the instrument cluster harness so i can utilise the stock instrument multipin plugs and labelled all the wires to make soldering it together easier. I'm not using 4 of the stock wires (alarm -, alarm +, coolant temp, low fuel) so I've removed them. Also cut most of the connectors off the Acewell gauge as they were huge and would not fit well.

The length of the wires coming out of the gauge means they would only just have fitted inside the frame behind the headstock. I figured it'd be neater if I just soldered them together and heatshrunk it all. The small 2 pin connector still on the gauge is for ambient air temp. The sensor comes pre fitted with the male connector so it made sense to leave that in place.

I will also probably fit the 1Mohm resistor on the tach signal as well as running a wire from the fuel level sender to this gauge. That will mean disconnecting it from the ECU but I doubt that will cause any issues. I think the only thing the ECU would do with that signal is turn the fuel light on and off and I'm not using that.
Hopefully it won't cause error codes. If it does, I guess I'll just fit a resistor from Gnd to the ECU wire so it thinks it's measuring the fuel level.

I'll also have to run switched +12V to the road speed sensor as the old speedo used to do that.

The dodgy aluminium bracket mounts to the same part of the triple tree as the stock gauges. I have this one offset to the right so I can mount my GPS to the left of it and they both fit behind the screen. I'll clean the bracket up later once I have it all working. I'll round off some edges so it doesn't look so square and paint it black.

Once the GPS is beside it and the screen is in front of it, you'll hardly see the bracket anyway.

 

[TURBO200R4]

@ChrisACT you are 100% right. My bad. I should have looked at the prints first before passing on that assumption of how a typical coolant temp sensor circuit works. Checking the prints, the ECM does appear to monitor feedback from that sensor as you stated. Learned something. Let us know how it goes and pics always appreciated.

I would guess u could just short the two wires on the on-off switch then install the resistor heat switch and be done with that.
I never knew they had that sensor