Temperature light, how does it work?

[SpookDog]

@bird902

I’m guessing that there is a small Curcuit board in the loom somewhere, unless the sensor in the head has a thermo-switch encorporated in it on the later gauge free models? To tell the bulb when to turn on…

[dan28]

@bird902 if your going to fit a digital speedo may aswel fit one that has temp gauge an tacho its good to keep an eye on whats going on inside your engine kosso make a nice digi speedo with temp gauge tavho an also built in warning lights

[bird902]

@markus-w I heard of those failing, don't know if I can trust them but I guess it's my best option, just gotta check coolant regularty

[bird902]

@markus-w Also, the stock one is 1.1 bar so why 0.9 bar?

[markus.w]

This post is deleted!

[markus.w]

@bird902 to be honest bud I'm not familiar with bar. As I said they both state the same equivalent. As far as I'm aware the opening pressure is 12.8 psi. But I think you may be right about the quality of them. Not tried them myself but as Dan said digital ones are available.

[HOTSHOT III]

@markus-w 1 Bar = atmospheric pressure = 14.7psi, so (12.8/14.7)psi = 0.87 Bar

[Calum]

@bird902 I am currently running one of these. Seems pretty good so far. My speedo has packed up so it's a good way to get a basic idea of coolant temperature.

[markus.w]

@HOTSHOT-III am I right in thinking that the opening pressure is 12.8 PSI? I got it from the Haynes manual but they have been known to make mistakes. Bird902 got me thinking now as he/she said it's 1.1 bar.

[HOTSHOT III]

@markus-w Just looked in my '88 (round slide carb DTR) Yamaha service manual, they say 10.7-14.9psi. But both my '98 bikes have 1.1 (16.2psi) stamped on the rad cap, one of which I bought genuine by part number for that specific bike by VIN number to try before replacing the head gasket (it was losing 150ml of coolant every 90 miles when I bought the bike).

So it could be the case that Haynes took the figures from the '88 manual, stated 12.8psi as an average, then never bothered to update it as they've made similar inaccuracies with carbs and stuff. And there's a myriad of small differences like that between the '88 DTR and '89 onwards.

[markus.w]

@HOTSHOT-III yes I've noticed a few mistakes. Thanks for clearing that up.

[bird902]

@Calum what would be considered high temperature on one of those?