Dashboard issues :(

[Evsi]

Hi folks, wondering if anyone has any ideas as i'm going out of my mind!I have searched the forum but can't find anything similar.

Had an issue with my battery light not working on the dash last week, so checked all the alternator connections and outputs - all seemed fine. I then took the dash out and removed the multiplug which all looks fine, however when i re-connected it, the temp gauge then went all the way to hot (red led also flashing) and the battery light was back on (ignition on only). When i start the van, the temp gauge returns to normal (red led stops flashing) but the alternator light stays on

I've checked/cleaned the earths behind the glove box, battery to engine, engine to engine compartment and even earthed the dashboard wire (brown No3) and nothing has changed. If i pull the D+ wire from the alternator the light goes out which suggests it's at fault, however it seems a bit of a coincidence that the temp gauge is obviously earthing somewhere it shouldn't at the same time? All the connections to the coolant sensors are fine also, so i'm just wondering if anyone has any ideas?

Cheers,

Jon.

[noggintom]

Hello,

I think the temperature gauge is supposed to do that to show it is working - someone else may be able to clarify.

I had the dash out of mine last year to replace the heater motor and cleaned up the dash pod connectors and the earth 'crowns' on the bulkhead at the same time. The temperature gauge then did what yours now does. I assumed that it was not working correctly before....

If the battery light is on and the electric's are otherwise ok I expect that the alternator is knackered. It may just need a new brush pack to get it going again depending on how old it is.

Good luck with getting it going again,

Tom.

[AngeloEvs]

It's difficult to give diagnostic advice in your case but my approach when investigating dashboard faults is as follows:

With Dasboard removed:-

1. Visual inspection of of the PCB membrane edge connector strips for damaged , broken tracks, non conducting .

2. Point to point continuity measurement from each Membrane edge connector to the relevant component , i.e Resistors, gauge/clock terminals, regulator, DOPS connector,etc,

3, In your case a resistance measurement across tracks 3 and 6 (Earth to temp gauge output).

Followed by a full function tests with Dashboard on the bench. I have a test rig for doing this as I am often asked to repair/modify dasbboards for owners but you can do it using small crocodile clips to power the dash and then ground or ad secondary 12V feed to the relevant pins if you are fully familiar with the dash circuit.

Note: When testing for short circuits across the temp gauge, you must remove the module numbered 43 in the fuse box as this is connected directly across the temp guage output and to earth - these can cause short circuit problems and removing it will allow you to focus on the coolant sender wiring if the fault persists with it removed.

[Evsi]

Thanks guys, appreciate the responses. I should also say it's a 1988 jx td. Ive had a quick look today and it's an odd one. If i disconnect the both wires from the temp sensors on the back of the head, the gauge still gives a reading and they don't have any effect on the gauge when earthed out either. I have added an earth to the housing that they sit in, to the body to be sure.

I've also checked the alternator again today and i think the light is to do with the regulator. I only have around 7v on pin D1 when running, so i'm guessing that's why it isn't canceling the light right?

Thanks for the help guys, it's a big help.

[Evsi]

Would anyone have a wiring diagram for the JX charging system by any chance? I think this is all related to the voltage regulator somehow......

[xpress]

angelo, is it same module 43 in the early 84 continental fuse box of tricks ??

[AngeloEvs]

I don't know where the module 43 is located on earlier WC vans. I have asked this a few times as, from what I understand, its not in the fuse box as in later vans - probably somehwere behind the dash I would think and whatever the number looks like a relay - marked 42 or 43 are the ones that I have seen and interchangeable?

[xpress]

feel free to add into Wikipedia, its third row back, to the left, you'll need a torch, and stretch out across the seats, you have to put your arm up from the bottom with glovebox down!

[Plasticman]

feel free to add into Wikipedia, its third row back, to the left, you'll need a torch, and stretch out across the seats, you have to put your arm up from the bottom with glovebox down!

not tried doing it that way