alt problem

GERRY · Post by **GERRY** » Fri Nov 27, 2009 6:28 pm

HI i am have a problem with the alt light or somthing mybe someone could help me with . when i start her up the light comes on as it should when i rev her up it goes off, this ok for a while but after about 20minutesit starts to flash on and off ,somethimes it will
stay on for a min/or so before it goes off , ihave checked the fan belt which seeem ok also have checked the wireing as best as ican which seems ok , the tractor starts ok so battery seem to charge ok , but the light flashing on an off is anoying , any ideas how to fix it would be welcome Gerry

Bensdexta · Post by **Bensdexta** » Fri Nov 27, 2009 8:13 pm

If you have a voltmeter, I suggest some basic tests such as:
http://www3.telus.net/chemelec/Projects ... rnator.htm
Beware of moving parts!

Post by **Brian** » Sat Nov 28, 2009 8:46 am

Have you fitted an alternator? If so, your symptoms sound like a regulator fault or a diode failure in the rectifier.

GERRY · Post by **GERRY** » Sat Nov 28, 2009 10:15 am

Thanks Bensdexta ,Brian this will be a big help . ill go out ant check useing the digram , ihave avolt meter but am not the best at useing it , ill see how it goes as the digran from bensdexta is good .I bought the alt new about 8mt ago , it has worked well since , having said that it was the second one at the time as the first give a few problems , the shop replaced it i had posted here about it , you must have agood memory Brian

, GERRY

GERRY · Post by **GERRY** » Sat Nov 28, 2009 5:52 pm

Hi again i went out started the tractor and light went out as usuall ithen done the tests as decribed , they checked out ok the light stayed off during tests i then took the tractor for arun after about mile or so the tractor had come up to working temp , it then per usual started to blink , itook it back homen with the light still blinking on and off i run the tests again , every thing is working an charging as it should. Brian when you talked about regulator and diode failure in the reciftier, do you mean in the altanator as i have no original wiring on the tractor . it has been working well all ove the summer . Any ideas are welcome as this driving me BLINKING mad

Post by **Brian** » Sat Nov 28, 2009 6:04 pm

We used to suffer from this exact problem on the wonderful German built (?) Bosch electrics on Claas Dominator combines. When the engine had just been started and the battery was taking charge, the light would be out, once the battery came up to charge the warning light would come on and stay on. Working at night with the lights on and it would be off.

I have had the same problem on my Fergy which is fitted with an alternator.

The problem is an annoyance rather than a problem and can be cured by adding a 1 amp diode between the light and the alternator in the exciter circuit.

GERRY · Post by **GERRY** » Sat Nov 28, 2009 7:04 pm

Thats the answer i wanted to hear, ill get me one of them an see how it works out , ill post how i get on . Gerry

Jerry Coles · Post by **Jerry Coles** » Sun Nov 29, 2009 9:21 pm

As a Diode is a one way device, which way should it go?

Post by **Brian** » Sun Nov 29, 2009 11:28 pm

Ring to alternator.

GERRY · Post by **GERRY** » Mon Mar 01, 2010 7:42 pm

Hi all ; i just thought i would up date on my alt warning light , i finally got a 1 amp diode , i could not get one localy but eventually found a shop that sold them, ididnt think they were so small , anyway i cut the small wire and soldered it on , with the small grey ring to alt as Brian described and the light is working now as it should , thanks again to Brians;know how once again

. Gerry

Raymondc71 · Post by **Raymondc71** » Tue Mar 02, 2010 11:10 pm

try and move the key in the ingition a small..

The Fordson Tractor Pages Forum

alt problem

alt problem

Alternator testing