Club 80-90 Forums

1885 1.9DG with 45A alternator. On starting, battery light dims slightly but stays on. Fan belt fine. Multimeter readings on alternator output gives just over 14V on tickover. Small blue lead from alternator seems to have good connection before dissapearing into loom so I assume loose connection somewhere under dash - any pointers for the where to start would be very useful. There is a auxilary supply switch for a 12v fridge which seems to take its feed from the ignition switch loom under the steering binnacle.

Are the symptoms the same as this:

https://club8090.co.uk/forum/viewtopic.php?f=39&t=119727" onclick="window.open(this.href);return false;

Alternatively, it maybe worth changing the regulator:

http://www.brickwerks.co.uk/index.php/v ... 3-all.html" onclick="window.open(this.href);return false;

Hi again.
Yep sounds very simialr to your post with the exception that the light does come on at normal brightness when starting. Think I'll order a regulator anyway (not exactly gonna break the bank) and take it from there so update in a week or so once the part has arrived and a get a pass to fit it!! Cheers

No worries Matt, let us know how you get on. How's the van coming along?!

Getting there, slow but steady! swivel base is in - the boys love it. MOT early next month so no doubt more bills.

Glad you got it in ok mate & the kids like it Got my MOT this Friday so keeping the old fingers crossed.

OK so heres an update. Ordered regulator pack from Brickwers (ordered sunday night and arrived tuesday morning - fantastic service as usual). Fitted this evening - also cleaned all contacts etc etc .
Put alternator back in engine and test results as follows:
Engine not running: 12.8 V on main terminal and 0.0 V on blue wire. Battery light on bright.
Engine running: 14.7 V on main terminal , 12.9 v on blue wire but..... Battery light still on but dimmer!
So now sunday morning job is, I guess, lift out instrument pod, disconnect 11pin connector and test for voltage there!
Not too worried but suppose I will have to fix before MOT at end of month - I believe that any warning lights on with engine running now constitute a failure???

Are you measuring the voltage at the alternator or at the battery?
Try measuring at the battery as it looks like perhaps the alternator-to-battery wire might not be sound?

14.7v seems high - usually about 14.2v with a modern 14.5v regulator.

Thanks for both replies. Yes, I was measuring output directly from the aternator. My voltmeter is a bit of a cheap and nasty job from B&Q so readings may not be that accurate. I did notice today that one of the main out cables from the alternator had a split in the insulation so I slapped a bit of SA tape round it. Hadn't thought of the main cables breaking down so will check both in morning and test at the battery. thanks again.

***FURTHER UPDATE*** just sneaked out and put the voltmeter on the battery connections - basically same as alternator - 14.7 V engine on at tickover (allowing for possible inaccuracy of cheap voltmeter). another thing has just occured to me..... there is a battery isolator switch on the earth strap - could this be causing the issue - previous owner installed and as there are no manufacturer marks on it, I'm not sure of quality - can make lights slightly flicker a bit if i knock it. Quick fix to check that one and if no joy there, back to fault tracing the blue wire route back to the battery light I guess.

SamsBus2012 wrote:There is a auxilary supply switch for a 12v fridge which seems to take its feed from the ignition switch loom under the steering binnacle.

That seems a bit odd. A typical fridge pulls about 7 Amps so any "feed" from under the dash is likely to be inadequate and therefore suspect. On the other hand I have heard of folk using that blue wire (which is the wire that controls the warning light) to not only trigger a split charge relay, but sometimes to trigger a fridge supply relay. If that is the case in your installation then the "load" on that wire may be excessive and may be causing your problem ?

Oh, and as OBG says, 14.7 is too high. Suggest test with another meter. If still high, that dodgy -ve side cut off could be causing a poor connection that could cause a high reading at the +ve terminal (which can temporarily "fix itself" due to the huge current when cranking by the way)

SamsBus2012 wrote: Engine running: 14.7 V on main terminal , 12.9 v on blue wire but..... Battery light still on but dimmer!

That is where your problem lies it should match the alternator voltage. Try it again with the blue wire disconnected and a little flylead connected to the terminal start the engine and give it a rev to self excite the alternator and compare the voltages.

bigherb wrote:

SamsBus2012 wrote: Engine running: 14.7 V on main terminal , 12.9 v on blue wire but..... Battery light still on but dimmer!

That is where your problem lies it should match the alternator voltage. Try it again with the blue wire disconnected and a little flylead connected to the terminal start the engine and give it a rev to self excite the alternator and compare the voltages.

Very belated update - did all of the above plus changed regulator again which got output down to 14.1v. Cleaned all contacts and earths (including dash crowns), Big Herbs fly lead test still gave output to battery light around 2v lower than main. Still no luck so have ordered new alternator. Non oem but valeo so pretty good make and only £62. Worth a punt at that.