Is200 Voltmeter

[GWilso]

Hi guys I've got real concerns I may have a problem, I suspected I had a low running Battery as the voltmeter started to dip towards the 9volts were as previously it stuck around the 14volt mark, also the car struggled to start up a couple if times, according to the manual between 18-9volts is normal however I changed the Battery anyways it was probably due, now I have a fluctuating voltmeter while driving when I'm at idle it drops down to 9 volts and when I'm on the gas it rises to 14 mark I've and again I'm not always confident she's going to start up

Sorry to waffle on again! but I've never noticed any fluctuation before and am worrying there is an underlying fault such as alternator etc etc I've not long taken out a warranty with warranty direct and I'm not covered for ware and tear faults until after 90days and I'm guessing a new alternator would bring me a nice bill if £500. car is 05 and only done 70k am I just being paranoid or has anyone had similar experiences?

thanks for your time

Gordon

[steve2006]

It certainly looks like the alternator is playing up, there is an inbuilt regulator within the alternator which is there to prevent voltage variations like you are getting.

To make sure have the voltage across the Battery terminals checked and see if the voltage also varys when measured this way.

First thing to check is the drive belt for condition and tension as this could cause the same problem.

Also make sure all the connections to the alternator are secure and good especially earth points which suffer corrosion on any vehicle.

If it is your alternator there are more routes than via Lexus for a replacement, look for a reputable company that does rebuilds locally and have your own done, buy a secondhand one and have that rebuilt then fitted to your car or buy a serviced exchange one with a warranty.

Or buy a working secondhand one

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=lexus+2005+is200+alternator&_sacat=See-All-Categories

[GWilso]

Steve thanks for the response mate it's as I thought regrettably, I'll get and have a look as soon as, were is the alternator located? Also I've not long had the cam belt done could it be related?

Thanks again

Gordon

[sparkystav]

Steve thanks for the response mate it's as I thought regrettably, I'll get and have a look as soon as, were is the alternator located? Also I've not long had the cam belt done could it be related?

Thanks again

Gordon

Could the belt be simply slipping on the alternator? if it youve recently had cam belt then they have to remove that belt to do it. and it may not be tight enough

[steve2006]

As I and Sparkystav said check the belt and tension first it may be the end of your problems.

It doesn't look from the diagram that the belt is autotensioned so it's normally a case of adjusting the alternator position to correctly tension the belt.

The alternator depending on which engine you have fitted is either top right or bottom left of the engine, the other pullies the belt goes over are the crank pulley,water pump and air con compressor.

I don't know the correct belt tension check proceedure but a good guide is you shouldn't be able to twist the belt more than 90 degrees on its longest section.

[GWilso]

Thanks for your time guys I've had a quick look at the belts all seems to be ok, but I'm not to sure what to be looking for best I take it back to were I had cam belt done and ask them to check it over and hope it's a simple fix! This is my 3rd IS and all I've ever had to replace is a brake light bulb hopefully it can stay that way

regards

Gordon