Here's a pic of the back of my temp gauge. What is the green thing and what is its purpose? Looks like someone has been in there before...
By tightening up the connections I have at least got the gauge to read, with much effort it will almost come out of the white 'cold' mark. I should next try the trick of wiring the two wires together at the sensor end to see how far it will move.
The gauge has worked happily since I bought the van, at least the last couple of years. It is as near to a 'normal' van as I could get!
Just tried connecting the two wires at the sender again but nothing happened. Sender is blue.
I'm loath to remove that resistor since the gauge used to work with it in place but maybe I have nothing to lose?
This is a basic van with the right hand dial being blank with temp at the top and fuel at the bottom. Can I replace just the temp gauge or is it all one bit?
Scared of dismantling things behind the dash, it all looks rather crumbly.
1985 1.9 DG Devon Moonraker with solid sided pop top
Its on the input 10v regulated side of the temp gauge and will have no effect. Absolutely no reason for it to be there, take it off and tighten the nuts.
I would not replace the gauge until I had tested it, they are a separate item and you can replace it.
... the only way with the the dash in place is by short circuiting the temp gauge output to earth. Not to difficult but you may need a small mirror or someone watching from the front of the van to help you locate the correct nuts.
If you look at the picture you posted you will see three nuts that secure and connect the temperature gauge to the circuit.
The middle nut is earth, the other one that did not have that capacitor attached to it is the output. These are the two you will temporarily link together with a piece of wire.
If you have small crocodile clips , attach them to a short length of wire and link the middle nut to the outer nut and switch the ignition on - the needle should start to rise. As soon as you see the needle start to move switch the ignition off - there is no need to watch the needle move any further to the right , doing so is not advised as 10v shorting to earth will generate heat. If you are using a small scredriver or short length of wire and connecting by hand then switch the ignition on first and get someone else to watch the needle as you concentrate on shorting the nuts together.
So, some progress. Guidance much appreciated but sorry, more is needed.
I have removed the capacitor and tested the gauge using AngeloEvs instructions.
The gauge comes to life and appears to be fine.
I then go back to the engine and join the two connections in the plug for the sender together.
I sort of expected this to make the gauge respond with the ignition on but it did not.
So I'm not quite sure what to do next.
Am I working with the correct sender? I'm at the one on the left hand side of the thermostat accessible from above.
Should I by pass the existing wiring from front to back? Seems a bit extreme and I don't know which of the three terminals on the gauge to make use of. Earth and output or input?
1985 1.9 DG Devon Moonraker with solid sided pop top
There are two senders in the thermostat housing , one is the switch for the carb heater , and is the one nearest the wheel ,
The other is the temp sender for the gauge , it faces towards the front of the van
Pulling the plug off and bridging the two connections in the plug you have off the sender will make the gauge rise to the hot end, and the red light flash once past 7/8 of the way to the hot end .
Thanks, that was somewhat stupid of me, should have looked further.
After typing my last I went out to have another look, found the forward facing sensor and had a go at bridging it for few seconds. Nothing at the gauge. Went for a short drive, needle appeared and then dropped back out of site again.
Now I start to wonder if I left it for long enough to respond when bridged. Might try again when it has cooled down a bit.
1985 1.9 DG Devon Moonraker with solid sided pop top
Just had a look, the colours of the two wires leading to the forward facing sensor are red/yellow and brown. Rather than bridge the two together as I have tried should I earth one to the engine as per the wiki?
1985 1.9 DG Devon Moonraker with solid sided pop top
Ground brown wire to engine and gauge does not respond. Brown wire is quite brittle close to engine.
Ground red/yellow wire to engine and gauge responds
Bridge two wires together, no response.
Tidy up connectors on brown wire and bridge the two wires, gauge responds.
Refit and drive round the block, gauge moving a bit and dropping away as before. No change.
So either my fiddling with brown wire has fallen apart already or the sender is faulty???
1985 1.9 DG Devon Moonraker with solid sided pop top
IMG_4191 by dralowid, on Flickr
