Dear all,

Today when I am cruising along the highway, I suddenly got two fault messages on the desh. They were "Air Suspension Fault" and "cruise not available". The yellow warning light on the dash was on as well. The ride has then become very harsh.

When I reach my parking space, I found that the ride height is absolutely normal, which I think the air suspension is totally fine as I replaced my air compressor and front shocks 2 months ago.

Any idea? Could that the battery? Appreciate for your helpful advices in advance.

 

What is the age and condition of the battery? After ten minutes with the ignition in the off position, there should be a minimum of 12.6 volts across the battery terminals. If not, the battery should be replaced.

Many of the odd electrical faults discussed on these forums can be traced to a failing or weak battery.

 

Thanks for the reply. Yes I will use a multimeter to check the voltage of the battery later this week as I don't have time today. The battery was purchased for my previous BMW E39 around 1 year and 9 months ago, then I switched the battery to my Jag when I bought it.

learnt from this forum that many fault messages can appear when battery voltage is low, I will check the battery first.

Another question, do the alternators on the X350s last long?

 

As with all automotive components, some last longer than others.

 

You could try rebooting the car.

Remove battery leads and touch together for a minute or two and replace the leads.

 

New brushes, bearings, greased, after a good cleaning, usually works as well as a new one, and just as long. Put new diodes in if you want to be extra careful, but if there were no issues with your present alternator. But mileage is getting up there, with preventive maintenance being your goal, this is what i've done for more years than i care to remember.

 

Hi all,

I just used a multimeter to check the battery voltage with the car off. The voltage is around 11.65V. Then when I started the car, I checked the voltage again across the battery terminals and the value is 11.2V. Does anyone know why the voltage is even lower with the car switched on?

I guess 90% is the alternator failed.

 

It does appear that the alternator has failed. The best way to ensure everything functions correctly is to remove the alternator and take it to an automotive electrical specialist for testing and overhaul.

As was suggested above, the brushes and rectifier assembly can be replaced to bring it back to specification.

 

Thanks for your reply. Since there aren't many people rebuilding parts in Hong Kong, I think I will buy a rebuilt one from UK. Thanks!

 

Be certain that the one you obtain from a UK supplier is for your vehicle so there are no warning lamps that come on in the instrument cluster.

You can check with S.N.G. Barratt and see if they have one for your vehicle, but bear in mind they are VIN-specific:

https://www.sngbarratt.com/uk/#!/Eng...TOR%20ASSEMBLY

 

Yes I checked SNG Barratt and thry have it on the list. However, I also found some on eBay which are rebuilt and cheaper. Let me do some research and see which option is the best. Thanks!