How long can you drive with a failed alternator

[ISL]

Currently on holiday in Wales with a 3 hour journey home. It appears that the alternator has failed. Have fully charged the battery and will keep it trickle charged for another 24 hours. Currently trying to find a mechanic in Pembrokeshire before we return home to Herefordshire tomorrow. Added problem is that we are also towing a caravan.

Any help or guidance is greatly appreciated.

[Tannaton]

Not very long….

When being driven the car uses a lot of electrical power, as well as the engine management, injection system and fuel pump other big users of electricity are the climate control (which you can switch off) and if your car has electric power steering, that uses a huge amount, and also the ABS brakes.

The other thing to keep in mind is as the battery voltage starts to drop, different systems will start to behave oddly and then fail completely, this will cause error messages, warning lights and fault codes, and can be dangerous as it affects the brakes and gearbox shifting, when the car finally stops you will be stranded, and as you get out it’s last act of defiance might be to apply the electric handbrake….

If you do drive a short distance to a garage, keep the climate control off, radio off, and switch to side lights so the daytime running lights are off (unless you have a car with LED DRLs).

You have no chance of getting even halfway home with a failed alternator.

[john.wigley]

Originally Posted by ISL

Currently on holiday in Wales with a 3 hour journey home. It appears that the alternator has failed. Have fully charged the battery and will keep it trickle charged for another 24 hours. Currently trying to find a mechanic in Pembrokeshire before we return home to Herefordshire tomorrow. Added problem is that we are also towing a caravan.

Any help or guidance is greatly appreciated.

Sorry to hear of your predicament, 'ISL'.

I'm afraid that this, without being facetious, is a bit like asking how long is a piece of string.

Much depends on the size / capacity and the age / condition of your battery.

Your will, of course use less of your stored electricity if you do not require lights, wipers, heater fan, radio, etc., etc., on your journey. The more of those that you use, the less the battery will last.

You mention that you have a caravan. Could the caravan battery be pressed into service in the car in an emergency?

As a guide, my wife once made it home (just) with a failing alternator on a one hour commute in her 740, so I think much more than that will probably be pushing it (perhaps literally).

Do you have a recovery service that you could call upon? (Presumably not?)

Is there a forum member local to where you are reading this who may be able to help in some way? E.G. by recomennding a local garage, for instance? (Quite possibly)

Either way, I hope that you can resolve this problem - it is an unfortunte way to end your holiday.

Regards, John.

[Tannaton]

Originally Posted by john.wigley

As a guide, my wife once made it home (just) with a failing alternator on a one hour commute in her 740, so I think much more than that will probably be pushing it (perhaps literally).

However a more modern car uses more electrical power as it has many more systems, so if an hour is possible in a 740 I would suggest you would get less than that in a modern car. The big factor is if your car has electric power steering or engine driven - if it's electric then you've probably got 15-20 mins max. It may be worth calling FRF in Swansea - they're often complimented on here as being a very helpful dealer.

[archie159]

Originally Posted by ISL

Currently on holiday in Wales with a 3 hour journey home. It appears that the alternator has failed.

Has it completely and utterly failed, ie is generating zero electricity? Or is it failing - still producing some, but not the expected amount? I'm no mechanic, but have been driving for almost 40 years, and have had a few alternators fail in that time - but none have gone from hero to zero overnight, they have all given indication of being on the way out before they completely went. If yours is at that failing-but-not-failed stage, perhaps if you can be very economical with electricity usage, keep the revs high, then maybe you might get home? I assume you have an alternator warning light showing - if you get the revs high enough does it go out?
The only other comment is that one time one of my cars gave every indication that the alternator was failing. As the battery was also old, and I couldn't find anyone who could fix the alternator there and then, I replaced the battery. Took the car to the dealership (Honda in this case) who charged me £50 to tell me that yes indeed, the alternator needing replacing - and quoted an enormous sum to do it. I decided to see if another independent garage could do the job for less, so took the car there. The mechanic queried why I thought the alternator needing replacing, and did some checks himself. His conclusion was that the alternator was probably fine, and I should wait and see if the warning lights reappeared. Two and a half years later, no problems. So my point is, are you certain it's the alternator, and not just a failing battery?

[ISL]

Thanking everyone for their kind messages, just to provide a quick update, it is the alternator belt that has failed not the alternator. Just waiting for AA to arrive.

Will provide an update later, thanks.

[Moomoo]

Excellent news!👍

[ISL]

AA said they are not coming out and referred us to a local garage. The garage have said that they can recover car, caravan, passengers and dogs, but dogs will have to stay in the car which we are not happy about at all with temperatures close to 30 degrees and extremely intense sun. Also garage can only recover us half way home, then a second recovery truck from another garage will take over.
Not happy with the AA at all.

Contemplating trying to source an alternator belt and fixing myself, has anyone done one of these and how easy to fix?

Thank you.

[BorderVolvo]

So you're heading home tomorrow and the AA have a heads up you're needing a new alternator belt yet they'd rather pay a garage to recover you??
The AA used to offer their patrols an incentive called "enhanced repair", it was to save on expensive recoveries such as what you're describing.
It's in yours and theirs best interests that this is resolved by the fitting of a new belt......I'd be arguing this with them.
Downside might be if there's a reason other than the belt failing with age that has caused this to happen??

Best of luck, not a great end to your holiday.

[john.wigley]

Originally Posted by BorderVolvo

So you're heading home tomorrow and the AA have a heads up you're needing a new alternator belt yet they'd rather pay a garage to recover you??
The AA used to offer their patrols an incentive called "enhanced repair", it was to save on expensive recoveries such as what you're describing.
It's in yours and theirs best interests that this is resolved by the fitting of a new belt......I'd be arguing this with them.
Downside might be if there's a reason other than the belt failing with age that has caused this to happen??

Best of luck, not a great end to your holiday.

Agreed. As an aside, 'B.V.', on the rare occasions that we have called upon the AA - and Linda has 50 years unbroken membership - we have always felt that we received better service when a patrol attended than when a subcontract garage did so.

I am particularly concerned regarding the apparent disregard for the welfare of 'ISL's dogs. That is unacceptable, unforgivable in this heat and very probably illegal - an owner could well face prosecution if they did so.

Regards, John.