Battery Light appeared, voltage drop

[Outatime]

Hi Guys,

Been offline for ages due to an accident that require staying at the hospital... but here i am again.

Went for a spin today, but the battery light suddenly shown and the voltage gradually drops.

CHecked that the drive belt is still running and the pullies are still spinning correctly. No fuse were blown.

Is there anything else to check? And does this mean a new alternator is required?

Cheers!

[Barson]

I'd check what is coming off your alternator and also check your battery output

Any trouble starting?

[NickT]

Glad to know you are OK now !

With the ignition key in position 2, does the alternator warning light come on the dashboard? If it doesn't then check the lamp, the holder and the wiring back to the alternator (W) is OK. This lamp is required to excite the windings in the alternator etc...

Double check the earth lead from the engine to body and from the battery to the chasses at the right hand TAB bush bracket. With the battery disconnected, check the security of the locknut on the B+ (Battery) ring terminal that has lots of brown cables going to it. It may need a clean here.

If the car hasn't been used for a while, remove the battery from the car and check that it has water in it. If you can top it up, fill it up so it is about 2mm above the metal plates using de-ionised water.

Re-charge the battery using an automatic battery charger for sealed batteries (or undo the battery caps and use a normal charger).

Charging time depends on Ah rating of the battery and charge current.
eg for 70Ah battery, a 5 Amp charger will take 14 hours assuming that the battery is flat. Auto chargers are easiest

Once charged leave it for an hour to settle then re-install in the car.

Connect a multimeter to volts and connect between the engine and jump start post. You should get battery voltage >12.5v

Disconnect the coil connection or fuse 1 (I think) then get a friend to crank the engine over. If the battery voltage doesn't go below 9.5v then it is charged OK.

With the engine running at idle with no load you should see between 13.5 and 14.5 volts steady. With the main lights and air con on it shouldn't go below 12.5 volts (for the 90 anmp alternator)

You may be lucky that the alternator needs a few gentle taps with a rubber mallet to release sticking brushes but sods law will say not.

Hope this helps

NickT.

[Outatime]

Thanks Nick!

I will try to check those when i can craw under the car~ Still walking on crutches at the monent and can't drive a manual....

But I have high feeling that the alternator is dead... might be a good excuse for a 150amp alternator

Will leave the car standing for the time being~

Thanks again guys!

[Guinney1971]

hmm.........my alternator is buggered too

My car, when driving is running at about 10-11v, but occassionally it 'surges' and the dashboard lights glow brighter and the fan blows harder - when it does that, the needle goes right up to the top before dropping down again.

Just had a visit from Darren "God" Bowker, and he's recommended the 105 alternator that was used on the R25 Turbo with Air Con....... (hens teeth? :lol: ) Darren's keen to come along to a tech meet if we can sort one out before winter sets in, as he's a real PRV expert. He's dropped me off a venturi for nowt (got 'loads of em' he said) and he'll also sort me out a Renault 30 CPR and see if we can finally sort out the way my car runs. Cant wait! lol

[NickT]

Has he got lots of spares? Sounds like a handy person to know. Maybe he can supply lots of the volvo conversion stuff eh !

We should get a tech meet sorted soon. Maybe do one on your car to sort out the rich running once and for all eh !

NickT.

[Guinney1971]

haha, well, Darren is the Renault 30 expert and has been working on PRV engines for years. He's actually working on a 'PRV Testbed' car at the moment, which non turbo'd, should be over 200bhp. He said the PRV never turbo'd well and prefers to tune normally aspirated engines.

He's got plenty of PRV bits, but they are mostly Renault bits as opposed to Volvo ones. He wants me to fit the Renault venturi on, then he's gonna come over and tune the car up properly and probably fit a R30 CPR too (vacuum plumbing is alot simpler too). He is thinking, that my car is running so lean, that it is chucking unburnt fuel out of the exhaust. I must admit, it will be a revelation to finally get my car set up properly and to get more then 18mpg out of it - Sorbet does an average of 25+mpg and she's an Auto! :? Darrens looking forward to experimenting on my car it seems :lol:

He's also offered some useful advice to us for the LPG conversions too

Darrens very interested in coming along to a tech meet, so if folks wanna stick their heads together and come up with a mutually agreeable date and place, then we'll get it sorted

[Outatime]

Is there any harm in installing an alternator that is rated more than needed??

And anyone got comments for the specialtauto.com alternator? There are 3 available... is the 150amp the most secure choice?

I remember someone said that there's an alternator that collects water and is not good in the long run... is it the specialtauto alternator?

And are there cross reference part for the alternator?

[Guinney1971]

Hi John,

to be honest, and from speaking to various people, there is no point putting on a huge alternator thats producing 50% more then the car needs.

I'm gonna get a 105 alternator - I doubt I'll find a second hand one - so will have to bite the ole bullet and cough up for a new one. I'll see if I can find a parts x-ref for one, but if in the meantime anyone else knows which one it is please feel free to reply

[bozzzydmc]

Personally speaking i have one of the 140 amp alternators, its been on #2001 for 3 years+ now, with no problem with anything electrically being on. Its also a nice compact unit. I agree with Claire probably a bit over kill but especially with the $ to £ rate its still a good buy. Maybe now i would have gone for the DeLorean D110 + @ $189.95 ?? plus you get a alternator belt 'free' with each purchase.

Obviously you have the tax and delivery to take into account with it being from the US.

http://specialtauto.com/delorean-parts/alternators.html

Like thats been said, a good battery and alternator is the heart of the car.

[Outatime]

Did what Nick said today, and no luck... I need a new alternator.



This is what it says on the back of mine.... Is the alternator I currently got the original one from 1981? (P.S. it also says on the side: Made in France)

If not, I might try to source where I could get an identical one....

[Outatime]

On another note, before I start making huge mistakes.... anyone got any tips for removing the alternator off the car?

e.g. Like belt off first? or someting?

[Barson]

disconnect the battery
put your car up on ramps
don't let the alternator drop onto your face.
make sure you have the correct length belt for the new one you're installing.

[bozzzydmc]

Wise words indeed

[Barson]

perhaps they're not in the right order, but...