wiring in an electric temp gauge

Post by **callyspoy** » Tue Feb 19, 2008 8:30 pm

hello! dad has asked for this one...does the temp gauge need a voltage stabiliser hooked up to it? he thought it did, tried it and it didn't work. tried it without, it didn't work. he did a test on the gauge and he says it works, tried a different thermostat thingy-ma-bob again, still not working. it is hooked up to the same stabiliser as his fuel gauge, which does work. so all a little confusing!
if anyone has a wiring diagram, it may help, although he is generally a bit of a whizz with these things

cheers
*C*

Post by **callyspoy** » Tue Feb 19, 2008 9:42 pm

now i have just looked through old posts on here, and all seems like he is doing it right...so why is it not working!? what are the "B" and "I" contacts on the gauge and stabiliser? he currently has the "B" terminal as the input...as stated to do in the trusty old haynes...

Post by **Matt** » Tue Feb 19, 2008 9:50 pm

What happens if he touches the wire that goes to the sender to the block/earth on the battery?

Post by **callyspoy** » Tue Feb 19, 2008 10:14 pm

it goes off the scale!

Post by **alex_holden** » Tue Feb 19, 2008 10:28 pm

Did the sender and gauge come as a matched set?

Post by **callyspoy** » Tue Feb 19, 2008 10:34 pm

hahahahaha! of course not! the sender was the one fitted to the engine you see...would it really make THAT much difference? gosh...glad i have capiliary in mine!

Post by **MoggyTech** » Tue Feb 19, 2008 10:59 pm

callyspoy wrote:hahahahaha! of course not! the sender was the one fitted to the engine you see...would it really make THAT much difference? gosh...glad i have capiliary in mine!

Electronic gauges use a sender that is a thermistor (Variable Resistance with Temperature changes), and you need the one that comes with the gauge. Thermistors vary in their resitance range v temperature and there are many different ranges of Thermistor.

Post by **Packedup** » Wed Feb 20, 2008 12:04 am

MoggyTech wrote: Electronic gauges use a sender that is a thermistor (Variable Resistance with Temperature changes), and you need the one that comes with the gauge. Thermistors vary in their resitance range v temperature and there are many different ranges of Thermistor.

However, I have never had a problem swapping senders and gauges around. I've used A series senders in Triumph engines and vice versa, same goes for gauges.

If the gauge is working when 12v is put through it, and works with a 10v stabilised feed when the sender wire is earthed, then really the only place to look for a fault is the sender. I can't remember which terminal is B and which is I, but you want to take the sender from the light green wire not the darker green.

It's not unknown for senders to just give up whilst sat on a shelf, so I'd try throwing a different sender in. Whatever the variations in matched sets the gauge is very simple (just a bimetallic strip with greater resistance one side, so as power flows through one side expands quicker deflecting the needle) and any sender in working order should pass enough juice for the needle to at least shift a little.

Post by **Mogwai** » Wed Feb 20, 2008 8:39 pm

I just fitted the guage back into mine & it refused to work i think i got the terminals back to front on the guage swaped them round & working ok now. The markings on the voltage stabiliser are B for battery & I for instrument the body must also be earthed for it to work.