Club 80-90 Forums

As per title..... the dash battery/alternator warning light is illuminated.

Van/engine: 1987 1.6TD JX with 65amp alternator.

I have searched the wiki and tried a few things and the light is still illuminated?
Has anyone PLEASE got any tips or advice to try before the alternator needs changing?

Symptoms:
The dash light remains on following start up and when on a run glows dimmer, when the engine slows to idle it glows brightly again.
(obviously when more/less charge is generated by the alternator)

Attempts to rectify:
New voltage regulator (new bushes) - although old one wasn't very worn when replaced.
Checked voltage generated by alternator at both battery and alternator terminals - all seems OK?
Cleaned earth point at battery and all alternator connections.

As the alternator is generating sufficient voltage I think the fault lies else where!!?
Earths, wiring, the black engine wiring box (not sure where to check in the black box) or elsewhere?

Any tips or where to look or what to do now greatly received.

Thanks

What's the voltage on the terminal that has the blue wire connected to it? ( on the alternator )
With the engine running .

Thanks for the reply.

So I got home early and....

Measured the voltage at the alternator (blue terminal) and also at the battery terminals + & -
When running and increasing the revs slightly was getting 14.2-14.3v at both.

This leads me to think the alternator is OK and is charging the battery so the fault must be elsewhere ?

Any ideas anyone?

below are pics of the voltage regulator I fitted and no luck problem remains?

You might know this; when the key is in the first position ( oil,glow and alternator lights on ) the alternator light has 12 volts from the battery on one connection and zero on the other connection ( the blue wire at the alt )
When the engine is running you should have the same voltage (14.3 ish) on both connections to the light so it goes out!
So...you must have a poor connection somewhere ( ignition switch or wiring ) or possibly a very odd partial short!
Good luck.

Thanks Dave,
Will have another look.
I guess Im looking for a broken/damage wire or a bad/corroded connection?
I haven't looked inside the cab at the switch yet, all my diagnostics as been at the alternator and battery wiring.
hopefully it will be something obvious!!!???

Couple of things you might like to try to help diagnosis;
1) if it's simple to do, disconnect your split charge relay as that runs off the alternator blue wire and might be effecting things - disconnect and see if that changes anything?
2) if you have a long piece of wire; with the engine off disconnect the blue wire from the alternator and with the ignition key on, jumper the blue wire to the battery positive - is the light fully off

MidLifeCrisis wrote:Couple of things you might like to try to help diagnosis;
1) if it's simple to do, disconnect your split charge relay as that runs off the alternator blue wire and might be effecting things - disconnect and see if that changes anything?
2) if you have a long piece of wire; with the engine off disconnect the blue wire from the alternator and with the ignition key on, jumper the blue wire to the battery positive - is the light fully off

Thanks M.L.C,

1) The leisure battery is currently out of the vehicle do you think I still need to disconnect the split charge relay?
(the fault was present prior to removal of the leisure battery and the fault has remained the same after its removal)

2) My van is a diesel so the main battery is in the engine bay - are you suggesting disconnecting the blue signal wire on the alternator and connecting this to the battery +? - (I have long piece of wire if required thou?)
Should the light go off/on when the blue wire is 1st disconnected from alternator and then 2nd when connected to the battery?
What will this diagnose .. fault in wiring?

Thanks for your help.
Any input greatly received as Im struggling to find a solution.

Ta

So I got another chance to look at this.

I currently have the leisure battery out (treating and painting the batt tray)

I got access to the split charge relay (under the seat - Westfalia)

I removed the 2 blue cables (one I assume from the alternator and the other to the dash area, I assume again to the dash led?)
These are fitted in line i.e connected to the same terminal on the split charge relay.
Both appeared fine good connections.

When both blue wires were disconnected from the split charge relay and then connected together this made No difference!
(I wasn't surprised by this)

When both these blue wires were disconnected from each other at the split charge relay point (i.e now no feed from alternator to dash) This also made no difference!!?
(I was surprised by this and expected the dash led/light to just stay constant and bright but it didn't, it came on as before and dimmed when revs were increased?)

This was exactly the same as prior to the tests above but with everything connected?

Has anyone got any help or ideas?
Im starting to struggle here.

Im starting to think the fault must be under the dash? As the fault is still present when no blue alternator signal?
Broken wire or bad earth?


Help very much appreciated. Thanks

Going back to MidLifeCrisis suggestion, and your 14 Nov response, when you disconnect the blue wire from the alternator, if all is working correctly , you would expect the alternator warning light to be on. After all the lamp
Indicates when you t USB getting enough volts from the alternator. And when you connect the blue wire to the battery positive terms bam, it is getting plenty of bolts so you would expect a he warning lamp to go out.

So try the blue wire to battery test. If you get a warning lamp showing, and I read that you have good volts at the battery, that suggests that you have a fault elsewhere in the wiring, maybe in the dash insert.

I'd suggest that you look st the wiring diagram to be found on the syncrosport website (I've spent ages looking at it recently and can now follow it pretty well, but it has been a steep learning curve), and follow the blue wire through from the engine bay to the dash, checking for continuity at each stage. My van did not have the T2f connector near the alternator, but everything else should be pretty normal (fingers crossed. You've probably no idea what previous bodges have been done). Checking for continuity, as you probably know, means checking that there is no resistance between the two point you are checking. Set multimeter to ohms or circuit test, and you are looking for the same result as when you touch the two probes of your multimeter together.

For parts of the circuit that are some distance apart such as the 3pin connector in the black box, and the connectors on the back of the fuses and relays, use an additional longer wire. I used a jump lead, with its handy clips on each end.

So check from the alternator end of the blue wire to the 3 pin connector, then from the 3 pin connector to E13 (that's a bugger, E is the black multipin connector right in the middle of the connector board at the front so you have to prise out D or C as well, though if you've a slim probe you might be able to put it down from the back where the blue wire goes in, rather than unplugging it), then check from E13 to B1 (which really should be fine unless maybe a previous owner had something go melty in there?!). B1 should have a blue wire coming out of it, so check that from B1 to the T14/11 on the 14 pin connector at the back of the dash instruments (sorry, can't remember which way the numbering goes but it's blue...). You can see this if you put you head in the drivers footwell and look up, doing that neck breaking exercise saves taking out the instruments. You should also be able to check that the 14 pin connector is fully pushed home. Give it a shove, if you can reach it.

Any faults along the way should be rectified.

Alternatively go straight to the 14 pin connector, and check it is properly connected, then do all the other stuff.

Then If all that's ok, comeback here for more, cos that's me out of ideas. Oh, and check that the earth at T14/3 is a good earth.

Wiring diagrams are bliddy brilliant...

Same info really

Not sure if Dervs are the same but there is a single connector from the alternator in the junction box, if it is the same as petrol is it ok?
There's also a multiplug 13 pin connector at the relay plate E13 is the blue comes out at B1 (blue) from relay plate
Finaly the 14pin connector as mentioned in the dash binnacle

Diesels go to a 3 pin connector in the black box, the other two wires (black and red/white)in it are to do with the glow plug system. It's a rectangular connector, not round like the 7pin ones. The rest of it might be the same as a petrol? **checks wiring diagrams ** Yes, they look the same!

RogerT wrote:Going back to MidLifeCrisis suggestion, and your 14 Nov response, when you disconnect the blue wire from the alternator, if all is working correctly , you would expect the alternator warning light to be on. After all the lamp
Indicates when you t USB getting enough volts from the alternator. And when you connect the blue wire to the battery positive terms bam, it is getting plenty of bolts so you would expect a he warning lamp to go out.

So try the blue wire to battery test. If you get a warning lamp showing, and I read that you have good volts at the battery, that suggests that you have a fault elsewhere in the wiring, maybe in the dash insert.

I'd suggest that you look st the wiring diagram to be found on the syncrosport website (I've spent ages looking at it recently and can now follow it pretty well, but it has been a steep learning curve), and follow the blue wire through from the engine bay to the dash, checking for continuity at each stage. My van did not have the T2f connector near the alternator, but everything else should be pretty normal (fingers crossed. You've probably no idea what previous bodges have been done). Checking for continuity, as you probably know, means checking that there is no resistance between the two point you are checking. Set multimeter to ohms or circuit test, and you are looking for the same result as when you touch the two probes of your multimeter together.

For parts of the circuit that are some distance apart such as the 3pin connector in the black box, and the connectors on the back of the fuses and relays, use an additional longer wire. I used a jump lead, with its handy clips on each end.

So check from the alternator end of the blue wire to the 3 pin connector, then from the 3 pin connector to E13 (that's a bugger, E is the black multipin connector right in the middle of the connector board at the front so you have to prise out D or C as well, though if you've a slim probe you might be able to put it down from the back where the blue wire goes in, rather than unplugging it), then check from E13 to B1 (which really should be fine unless maybe a previous owner had something go melty in there?!). B1 should have a blue wire coming out of it, so check that from B1 to the T14/11 on the 14 pin connector at the back of the dash instruments (sorry, can't remember which way the numbering goes but it's blue...). You can see this if you put you head in the drivers footwell and look up, doing that neck breaking exercise saves taking out the instruments. You should also be able to check that the 14 pin connector is fully pushed home. Give it a shove, if you can reach it.

Any faults along the way should be rectified.

Alternatively go straight to the 14 pin connector, and check it is properly connected, then do all the other stuff.

Then If all that's ok, comeback here for more, cos that's me out of ideas. Oh, and check that the earth at T14/3 is a good earth.

Wiring diagrams are bliddy brilliant...

Roger,

Thanks so much for your reply.
Really helpful and very thorough, has certainly pointed me in the right direction.

Wiring diagram and synchro-sport site a massive help (wasn't aware of this one!) thanks

Will have a further look and report back.

Thanks a lot

RogerT wrote:Diesels go to a 3 pin connector in the black box, the other two wires (black and red/white)in it are to do with the glow plug system. It's a rectangular connector, not round like the 7pin ones. The rest of it might be the same as a petrol? **checks wiring diagrams ** Yes, they look the same!

Thanks Kev,

Yes looked in the junction box (in the engine bay)
To be honest it was a spaghetti junction of wires and didn't know what I was looking at.
So just checked everything I could and made sure plugs were pushed together and connections clean etc..

Now I have a wiring diagram to follow and your info/experience will re-look at that.

Ta

Aye, I mind the first time I opened the junction box, just closed my eyes and shut it again!!! Take your time, wiring diagram in one hand, cup of tea in the other, working out what you're looking at. It IS spaghetti in there, but if you take your time you can make sense of it.

And feel satisfied and pleased with yourself for another new skill learned!

dave friday wrote:You might know this; when the key is in the first position ( oil,glow and alternator lights on ) the alternator light has 12 volts from the battery on one connection and zero on the other connection ( the blue wire at the alt )
When the engine is running you should have the same voltage (14.3 ish) on both connections to the light so it goes out!
So...you must have a poor connection somewhere ( ignition switch or wiring ) or possibly a very odd partial short!
Good luck.

So got I a chance to have another look at this today....

Working thru everyones suggestions and help including Dave's above I think I have narrowed it down

1st I disconnected the blue wire at the alternator and the light as expected stayed lit brightly.
2nd I connected this blue alternator wire to the Battery + and the light went out!!!!

This I think tells me that the circuit is probably OK

So...

3rd I rechecked the battery volts with the engine running = 14.3v
&
4th I checked the alternator blue terminal output + to the battery - = Only 12.6v
(as per Dave tips above)
This difference in voltage Im sure is causing the light to illuminate?

So questions....
Why is this different? What could be causing this? Is this new alternator time? (although it is clearly charging the battery OK)

Below are pics of the Blue Wire terminal (D+) on the alternator (with and without the cable connected)
Should there be another wire connected to the + spade terminal next to it (this is live and nothing is connected here? (engine is a 1.6 TD JX)

All help greatly received Thanks