temp and fuel guage nearly working - help!

[djw113uk]

I am sure this has been asked a million times, but i couldnt see the answer, so here goes again..
We have an 83 autohomes conversion to a T25? A reg.
The fuel guage generally reads zero, though having filled THE tank to the brim, it makes it just past 1/4. (just outside the red)
The red light flashes on the temp guage - but understand this is probaly a dodgy water level sensor?
The temp guage generally sits at zero, though if sat idling for 15 mins it too makes it nearly to the outer edge of the box on the left hand side of the guage - 1/4?

I have remvoe dteh whole dash cluster, and looked at the wiring and the connectors... I have found

The black plastic backing piece to the temp and fuel guages is broken off. It is skillfully held in place with copious black insulation tape. The voltage regulator? tca700y, has its left and rights pins connected into THE ribbon, but the middle one is unconnected and stood in free air.
From top to bottom (to the left of the votage regulator) I appear to have 7 resistors. the middle one is the fattest. With the igniton switched on the 2nd one down - pink with silver midle strip gets so hot you burn your fingers if you touch it.

Everything else appears to work. I have 12 volts at the right side of voltage reg, and about 6 volts on THE left side. If I short across ( eg join left and right legs together then my fuel guage goes up to 3/4 tank (about whats in there now!) This has no effect at all on THE temp guage.

Finally, on the middle of the temp / fuel guage cluster, the ribbon has two plastic points. one has a long copper strip of ribbon pushed over it, the other has a copper circle (in the ribbon) just next to it. - shoudl these be connected to something?

Oh, and THE terminal plug that goes onto the cluster has the top wire going nowhere.. just hangs loose under the dash. Also under THE dash is a yellow wire (with red stripe?) which has no power to it, but stops short (been cut) of the terminal.

Can anyone help with:
1. why do temp and fuel guages not work?
2. why does 2nd resister get so hot - what does it do - which circuit?
3. why is middle leg of volt stab. free? can i just join THE two together to make my fuel guage work?
4. what are the two copper bits in the ribbon in the middle of the back of the guage for? - should the be connected?
5. where can i get a wirng diagram?

6 a random one thrown in... anyone know how the original gas heater works? - I have a big with switch next to the zig unit. An orange light next to that which doesnt ever come one, a gas tap for it under the cooker, and big cigarette lighter type plug also under the cooker, and a clicking / clonking noise which occurs about 5 times when you switch it on, together with the red / green batter lights flashing, followed by silence, and NO heat. any info greatfully received.
Sorry for waffling on. If you need any more info then please just ask.

Thanks
DJW

[AngeloEvs]

First, the voltage regulator is not connected correctly and you should have 10.5V, no suprise then that the gauges are reading low. It should be connected with the centre leg to ground via a 22 ohm resistor. None of the resistors should get so hot though that you cannot touch them but the larger one is part of the ignition LED circuit but I will need to check the Bentley schematic before confirming this and I am at work at the mo. A picture would help to see just how extensive the 'bodge' is. The centre flexi connections that you describe sound like those used for the analog clock but once again a piccy would help to confirm this.

[djw113uk]

I'd need your email to send a picture. I cannot post pics here.
The resistor is pink, with the middle all covered in silver - not the usual thin strips!

What should i use as "ground" - is one of the wires an earth? Thanks

[AngeloEvs]

One of your ribbon tracks is a common earth for all components, usually pin 3 of the multipin conx (colour coded Brown) but I don't have access to my Bentley manual to confirm this for pre '86 models. My email address is in my profile, just click on my username on the left and select 'Email', you can send the piccy there and I will post it in the thread so that others can add their comments.

[AngeloEvs]

check your messages at top of screen, have sent you a PM as you are local.




From the picture it appears that the centre leg does not have a connection point, and either it is missing, or your regulator uses the tab to connect the centre leg to the membrane earth track. The Bentley manual shows the regulator for your year model as having all three legs connected but it references the pictures to USA and Canada models only. The UK version may be different or there were variations in manufacture between 80 and 84. Some were fitted with a resistor for the centre leg and some are shown as not requiring a resistor with the regulator middle leg connected directly to earth

Q1. Is there any evidence of a centre connection that may be missing as I cannot tell from the picture? May be another member will confirm that the tab is used for providing the earth connection as this is also connected to the centre leg.

The second resistor is definitley well cooked and it will probably require replacement but unfortunately Bentley only gives data for USA and Canada 80-84 models and indicates it is used for the oil pressure LED. Once again there may be manufacturing/regional variations and I would, with the pod removed, check the entire circuit and confirm which resistor feeds which LED.

I would remove the regulator and test it independently and then check the temp gauge (the regulators are expensive and some suppliers are charging scandelous prices so check it first!).

The circuit is fairly simple and a multimeter would be sufficient to perform all diagnostics, each LED has a series resistor and the regulator may or may not have one connected to the centre leg, thats about it and you can largely ignore the diode for the moment.

[djw113uk]

I think you have done well to get all that from my very poor pictures. You are welcome to pop round for tea (and to have a look) anytime!

i am a bit confused when you refer to resistors, diodes and regulator. I assume the 3 leeged device is the regulator tca700y (or similar) is written on it, and maplins want 79p for one (or equivilent) There is no sign of an old connection. The middle pin sticks straight out, with no signs of solder or anything to connect to nearby. when you say tab, do you mean that large area of copper that it is sat (and screewed) onto?

Oil light works as it should - goes out on starting, comes on as you turn off etc. Someone said it could be a thermal... something or other.. and "could" therefore get hot? No idea which you mean by diode?

I havent manged to affect the temp guage.. it does move, but only at the bottom of the scale. It could be the sender, but will tackle that once we know volt reg is right!
I will and follow the resistors to their component!
#
Thanks for your time on this

[AngeloEvs]

The diode is the black device second from bottom. The regulator (voltage stabiliser) is the three legged device and the metal section (the heatsink) that is part of it (and used to secure it) is also connected to the middle leg (99.9% of the time). You can check that quite easily. The resistor that is cooking may not actually connect to the ignition LED and may actually go to the centre leg of the regulator via the heatsink but is denoted as being connected to the oil pressure led on Canada/USA models which may be different to yours, hence the advice to trace every component and note which LED it feeds.

[djw113uk]

Okay, So its been a while, but the camper is back with me, and this time I hope to fix it!

The fuel guage still reads very very low, and the temp guage barely reads at all. THE little red LED in THE temp guage generally flashes all the time, but switching the headlamps on makes it flash less.

I have 10-ish volts at one side of THE regulater, and 6.5v at THE other side. The middle pin is indeed connected to earth via THE screw in THE backing plate. All 4 temp / fuel guage nuts are clean and tightened onto the ribbon.

On the multipin connector to the dash .. pins 1-14.
1 doesnt have a wire
2 is a brown wire which has been spiliced into another - it goes the the hazzard switch, the splice goes nowhere
6 is / was yellow / red, but has been cut and spliced to a thick green wire which dissapears through the bulkhead down in the passenger footwell.
11 has no wire either

And the reason it is back with me.... some scumbag had a go at the drivers door lock, so it is in stratford having the lock rebuilt... well it will be if I can find a replacement! The handle is okay, the lock barrel is dead. Anyone fitted one of those aftermarket remote central locking kits? I am wondering abut doing away with the barrel so nothing for scum to stick their screwdriver into. Aparanatly we arent allowed to wir ethe body dirct to 240V

[AngeloEvs]

I work In Stratford upon Avon and could pop round on a Monday or Tuesday evening. The regulator voltage is too low at 6V and sounds from your description like everything needs a good check over. PM me you tel no or I can PM my mobile to you.