18.7v from the alternator???????????

[Stuarty]

Hi guys i had a problem a while back with headlight bulbs blowing couldnt figure it out so i fitted a digital volt gauge and have discoverd that the voltage is jumping from 14.2v when driving up to 18.7v every now and then so theres my problem but why is is it doing this?The engine is a 2.7td have been told that the voltage regulator is the problem and have searched the forum and seen various threads regarding this but i cant find out if the regulator is seperate from the alternator or if its part of the alternator could anyone confirm this for me?

Cheers Stuart.

 

[jims-terrano]

Eeeek, I'd be getting the alternator changed double quick

Jim

 

[zippy656]

I always thought they were part of the Alternator....

 

[rustic]

I always thought they were part of the Alternator....

Having helped Shaun recently, the regulator is part of the alternator.

How fast are the glitches to 18 volts as if the battery was in good condition it would slow down the rise in voltage.

But to get to 18 Volts, the only item to produce this voltage is the alternator, and it looks like the regulator is not functioning.

Or it could be a broken or poor connection within the alternator, but as the engine revs increase so does the voltage pre-regulator, so clearly the regulator is NOT doing it's job.
Some alternator repair places can replace components within the alternator, but sometimes better to replace the whole thing.

Regards, Rustic

 

[Stuarty]

ok guys thanks for the info so it looks like a new alternator it is then!god theres always somthing eh,i saw a new one on ebay for 120 ish a hitachi iirc does that sound ok that included the vac pump aswell.

The voltage sits at 14.2 then it starts climbing slowly and peaks at 18.7 then just drops back down to 14.2?I had it up to the shops this morning and it was fine if the regulator was broken would it not be at 18 odd volts all the time?

 

[extreme-4x4]

the regulator is separate and comes with the brushes simple job to fix.

part is from hc cargo part number is 134687

ring your motor factors and they will trace it for you

i used

City Electro Diesel Services


(01792) 792010


Nantyffin Road South, Swansea, SA7 9RG


part is around £25.00

however to be sure , if you can wait a day or 2 ill post some pics on how to remove and re fit parts , its 30 mins easy job. and you can trace the right part, yours could be slightly different

 

[Stuarty]

Cheers that sounds much better than forking out for a new alternator thanks for that im not sure what alternators on mine though the car is an N reg Mistral auto 2.7td did all the tds have the same alternator?

 

[extreme-4x4]

give me a day or 2 and ill do you some instructions . you should be able to source the part you want by taking the cover off yours to get part number.
once you have the part number the rest is easy. might have to ring a few people to find someone interested these days. but big saving to be made . and even better you learn how to fix things so your sorted forever then

 

[rustic]

While on the subject of alternator repair, if you find your battery is getting flat overnight and you haven't left the lights on, then it may be a failed diode in the diode block within the alternator. (Or a failed regulator).

To locate the drain on my daughter's fiesta, I put an ammeter in line with the battery (ie disconnect the battery and connect it via the ammeter, a 10Amp multimeter was adequate) and noticed a 3 amp drain, I disconnected the alternator and it went to virtually zero.

WARNING : Don't try to switch any loads on or the wires to the multimeter will melt.

This helped me diagnose the fault.
Hope this helps for future reference.
Best regards,
Rustic

 

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[ShaunAFC]

Having helped Shaun recently

I can confirm that Rustic has been of great help. And indeed it is integral to the alternator

 

[Stuarty]

Great stuff thanks for all the info guys its a great help,i think i will just replace the alternator as they are cheap enough im not that handy with electrical stuff lol.