Alternator voltage all over the shop!

[DSL]

Out doing a few miles tonight, I experienced a loss of power, then it chiming in & out. I was only able to make it home on a very light throttle.

 

Whilst traveling at snails pace home I checked the stack & noticed the battery volts jumping around from 11.9 to 16 😳 Guess the lack of stable voltage was making the power chime in & out via the MBE

 

Having only recently put the engine back in the car, I am guessing on a loose connection or failing alternator being to blame

 

Then tried it again & was fine for a few miles then same again ☹️

 

[F355GTS]

Darren

 

If it's not a failed Alternator then it does sound like a bad connection at Alternator or Starter large connection, Battery terminals, Engine earth, Batt Master Switch

 

Mark

[Bio]

Hi

 

Had the same problem on my VX traced to a cooked/faulty regulator brush pack on the alternater.

Replaced...now ok

[silver-7]

err i think it might be the bit i connected on your engine *mad*

 

i had the same once and traced it to the smaller (of two) wires connected to the alternator.

voltage was all over the place and lights flickered slightly !

Its a bugger to get to the small nut (which had dropped off my car) as its close to the left side engine mount.

 

Alex

 

 

 

 

 

Edited by - silver-7 on 31 Aug 2007 22:32:52

[DSL]

Hi Alex, do you recon that its likely to be a the small wire nut thats come loose then

[silver-7]

thats the one, although im sure it was tight

[Jason Plato]

The alternator could have self destructed - it could be that the alternator gearing needs altering with the engine now reving to 8900 rpm ?

 

 

 

 

 

Taffia rear gunner

 

[DSL]

That's a point ❗ However I have one of the Hellier alloy pulley's that I thought down geared the Rpm .

 

Been busy hillclimbing all weekend, so have not had a chance to have a look at it, but shall checkout the loose nut theory tonight first of all

[Jason Plato]

ally pulley on the alternator or the crank pulley ?

 

I ran a hellier ally one on my crank pulley - but it was std rover diameter and my 1900K only needed to be reved to 8100rpm so the alternator speed was a tad high but bearable for short periods between 7800 > 8100, saying that I did wreck one alternator with rumbling bearings but he was 5 years old ....

The alternator pulley I used was std rover - I didnt realise Hellier made ally alternator ones.

 

Dave

 

Taffia rear gunner

 

 

Edited by - Dave J on 3 Sep 2007 14:44:52

[DSL]

Sorry Dave, its the crank pully thats a Hellier one, the alternator one is as supplied with the car.

 

So I take it, it is overspeeding beyond 8000rpm

[Jason Plato]

I will have to try and dig up the data, but I recall my calculations were that the max safe operating speed of the rover alternator worked out at 7900 rpm engine speed using original crank pulley and alternator pulley.

 

I know several inc Peter Carmichael have reduced the speeds but then this can result in no charge at low sppeds below 2000 rpm.

 

It may just be a simple loose wire Daren , but revs above 8000 would need you to reduce the alternator gearing I imagine to maintain reliability.

 

Dave

 

 

Taffia rear gunner

 

[DSL]

Thanks Dave, don't think it will be seeing too much action anyway so will chance it as it is for now. Here's hoping its just the loose wire

 

Too many toys 😬, too little time ☹️

[Rob Walker]

The R500 crank pulley is what you need. The alt pulley remains as standard rover.

[Jason Plato]

yes Rob

 

the ally hellier pulley is the same dimension as the steel R500 one

 

Taffia rear gunner