Temp gauge on zero

[dvisor]

I was fiddling around with the dashboard dials earlier. After reassembling it all, the temperature gauge now fails to rise. The mason alarm still chirps if I lower the setting slightly with the engine running, so I think the problem is just with the gauge. I'm pretty sure I reassembled everything correctly. Anybody got any ideas before I dismantle it all again?

Also, can someone tell me if the fuel gauge drops to zero when you switch the engine off? I can't remember, and I want to be sure I haven't got a problem with that too. Mine doesn't budge when I switch off.

Thanks

[francophile1947]

Fuel gauge doesn't go to empty.

[dvisor]

Fuel gauge doesn't go to empty.

OK thanks - that's good. Just need to sort out the temp gauge then.

[mikexgough]

if all was working before you removed the unit to do your dials, it could be that one of the long plugs is not quite pushed home.....

[dvisor]

if all was working before you removed the unit to do your dials, it could be that one of the long plugs is not quite pushed home.....

Yes - it was working before I removed it, so its probably something I've done. I'm sure the two long white plugs were fully pushed home when I reassembled, the mason connections screwed down fully and I checked that they weren't shorting the circuit tracks. When I fitted the new dials, I had to gently rotate the temp needle to 12 o'clock so that I could slide the dial over it into place, but no pressure was exerted on it so I can't see that causing any damage. I guess I'll have to remove it all again and see if there's any damage to the circuit tracks etc. Don't suppose anyone knows which pins are relevant on the long white plugs?

[g8dhe]

Yup its the "1G" Pin on the C1-01 Connector see below the diagram for the plug and sockets.

I make that the Green wire on the first connector.

[dvisor]

Yup its the "1G" Pin on the C1-01 Connector see below the diagram for the plug and sockets.

I make that the Green wire on the first connector.

Thanks Geoff (the sooner I get the temp gauge working again, the happier I'll feel )

[rita]

Fuel gauge doesn't go to empty.

Lucky You

[Doone]

francophile1947 wrote:
Fuel gauge doesn't go to empty.

Lucky You

[dvisor]

Yup its the "1G" Pin on the C1-01 Connector see below the diagram for the plug and sockets.

I make that the Green wire on the first connector.

Well, I'm baffled. I've had the dials out again, and checked the connectors and removed the Mason alarm, just to take things back to basics. Still no temp reading with the engine running. Checked the needle, and there's no obstructions. The circuit looks fine - no tears on the copper.

I'm having a bit of trouble matching the circuit diagram up to the rear of my dials. The diagram shows 3 long connectors, but I only have two connected on mine. There's no sign of a third plug anywhere behind the dash, and I'm sure I didn't unplug 3.

The one on the left in the picture below is the empty one. The only damage I can see is between the 3rd and 4th copper track from the right in the socket where the right hand connector goes. The a slight tear in the film - the copper tracks are good though.

Maybe the temp sensor is kaput (or maybe disconnected where I've been working on it)? If so, where can I find it? Is there a reliable way to test the gauge off-vehicle? I'd appreciate any help here!

[bongoben]

A lot of Bongos do not have the third connector, it's only used
for optional accesories such as ABS etc.

As you have been removing the temp gauge screws, you may
have over-tightened them and broken one of the coil wires.
You may have to remove the temp and fuel gauge as a pair
to repair it.

If you download Hayden Callow's gauge mod from his website
there is a section which describes how to do this.

[dvisor]

A lot of Bongos do not have the third connector, it's only used
for optional accesories such as ABS etc.

As you have been removing the temp gauge screws, you may
have over-tightened them and broken one of the coil wires.
You may have to remove the temp and fuel gauge as a pair
to repair it.

If you download Hayden Callow's gauge mod from his website
there is a section which describes how to do this.

Thanks for this. I do have ABS (felt it kick in once or twice too), so maybe I should have the 3rd connector? Oddly though, the warning light says 4W ABS, but mine is a 2WD. Maybe that's something for another post!

I was ultra-cautious when tightening the screws, but I guess its a possibility worth checking. What I really need is some way of testing the gauge in isolation. That way I may be able to trace the problem backwards.

[Actually, looking at the circuit again, the tracks on the 3rd connector don't go anywhere , so there's definitely no 3rd plug!]

[dvisor]

As you have been removing the temp gauge screws, you may
have over-tightened them and broken one of the coil wires.
You may have to remove the temp and fuel gauge as a pair
to repair it.

You may have it here! When I said I was ultra-cautious tightening the screws, I meant the two on the dial side. The mason alarm, of course, uses the T-U screw on the PCB side. I wasn't as careful with this one! I'm not hamfisted, but it is a slight possibility that I overtightened it. I haven't got a clue how to repair the coil if I have damaged it, but my next step has to be finding some way of testing it.

[dvisor]

I've just removed the gauges and found this! Look at the component at the top of the right hand (temp) gauge, it's cracked to expose the casing. Could this be the problem? Bit of a coincidence if not.

[bongoben]

On the bench it's simple enough.

Connect + 12 Volt to the IG terminal.
Connect - (ground) to the E terminal.

Connect about 5 - 10 ohms across the TU terminal and E terminals.

The gauge should swing accross to somewhere near maximum.
Experiment with it, different values will show different deflections.
The gauge is adequately protected and you will do no harm.

I you still get no movement then you will have to strip out the gauges.

Addendum.

As far as the resistor shown above is concerned, measure it with multimeter,
it should be 56 Ohms I think, maybe more, the case is high temp insulation
and a bit missing is not much of a problem, test it for continuity.