Problems, problems

[Tafford]

I was driving along happily this morning when I noticed the lower red warning light on the dash had come on. As I have always thought this was the oil pressure light I pulled over and checked the oil level - all ok - then noticed that the oil pressure gauge was showing the usual pressures. Given this I carried on thinking warning light must be electrical gremlin - it was lashing with rain at the time.

Also noticed that windscreen wipers seemed slower than usual - thought it was my imagination. About an hour later (car had been running normal pressures / temps throughout), the car started to splutter / misfire - pulled over again, and turned engine off. Then refused to restart - battery appeared to be flat. Luckily it was on a hill so I bump started it and managed to splutter the remaining 10 mins home. Battery was then so flat it would barely wind the window up.

Is it likely that the warning light that came on was in fact the the alternator /charging warning light - has anyone come across this being the lower light on the dash? (handbook says it should be oil pressure light)

If not, I assume the oil pressure light is operated by a different pressure switch to the gauge - where is this switch and how can I check which light it is connected to - presumably if I earth the cable to the switch it will illuminate the light?

If it can be confirmed that it is an electrical problem, is it safe to assume that the alternator is at fault?

Thanks for any suggestions!

[zippee]

Was it the Mil light on the bottom right side of the speedo?
If so it would most likely indicate that your 100amp fuse has gone, the one (I think) between the alternator and battery, hence the reason you battery would have gone flat as it won't have been receiving charge.

[ntel]

IIRC the "Parrot of Doom" had a similar situation. Turned out it was actually the alternator light that had come on and the alternator was buggered. I'm sure he will be along later to confirm.

[jonathant]

sorry to be dumb, but doesn't the charging light have a little picture of a battery on it, and the oil pressure light have a little picture of an oilcan?

anyways, seconded zippie. I had identical symptoms traced to a broken 100A fuse.

[Tafford]

Unfortunately none of the three LED's on my dash have any symbols which doesn't help much. I've had a look at another couple of threads and have confirmed that the bottom light can sometimes be the charging/alternator light so it looks like I just have an alternator problem, although it could be the 100A fuse too. Is there any way to tell which without testing the alternator?

[jonnyb]

Its the charging light on mine, its also for the alarm. Mines a 96.
The easy one to check on the car is the 100a fuse its on the drivers side just by the lower wishbone, in a black box type cover.

[GreenV8S]

It's well worth knowing which warning light is which, because otherwise when one of them comes on you have no way of knowing how serious it is.

For example if the oil pressure warning comes on and you know the gauge works, you might cross your fingers and hope the oil warning switch is playing up.

If the no-charge light comes on you may have lost the fan belt (in which case you could do some severe damage to the engine if you press on) or it could be an electrical fault in which case you may have an hour or so to limp home before it finally dies.

The two that are hardest to tell apart are the oil and ignition warning lights, because they both come on when you turn the ignition on and go out when you start the engine. The way to tell them apart is that the no charge warning light comes on briefly if you rev the engine and then switch off, and the oil pressure light doesn't.

[tafford]

Well I've started it up (amazingly enough in battery to just about start) and put a multimeter between the large terminal on the back of the alternator and earth - showed about 11.5v so I guess the alternator is knackered.

I did try and look for the 100A fuse but couldn't find one - do all early chim's have these?

Edited to add: Thanks GreenV8S - fan belt is OK - water temp was steady for an hour anyway so assumed that was OK. I'm now almost certain I have the lightd the right way round after 6 months of assuming them to be opposed!

>> Edited by tafford on Monday 24th October 17:50

[2 Smokin Barrels]

Fuse on chassis rail, near starter?

[tafford]

Thanks Steve - I've looked there but can't see it - I've just found another thread that implies not all cars are fitted with it. Would the fuse affect the multimeter readings on the back of the alternator which indicate an alternator problem?

[Ballistic Banana]

re the 100amp fuse,Isnt it sometimes up above the battery to the right of the fuse box too?

[2 Smokin Barrels]

Ballistic Banana said:

re the 100amp fuse,Isnt it sometimes up above the battery to the right of the fuse box too?

Yep, I reckon I had a Chimaera that had two! (The one in the battery box worked loose & set fire to it's plastic cover!)

[david beer]

The fuse in the footwell is the main fuse to the fuse box, if that went you would have nothing, ie no voltage at all. The fuse under the car would just mean the battery would not recieve a charge. My fuse under the car went and i had no warning light come on, just the volt meter showing 12v instead of 14 v.

[Parrot of doom]

I had a similar problem. Three lights on my dash in order of height:

Red - alarm

Yellow - oil

Red - electrics


The manual says that the yellow light is electrics and the lower light is oil - thats bollox, ignore it. Turned out my alternator was stuffed, and my car doesn't have a 100amp fuse either. Give the battery a charge, turn it over, and get yourself down to a local garage (doesn't have to be TVR) to see if indeed the alternator is broken. If it is, and can't be repaired, go to your nearest autofactors and purchase an exchange unit (you'll need another car/taxi to do that obviously)

[jonnyb]

Got me thinking now! I will have to go and check the LEDs on my dash. Oh well its an excuse to take the long way to work later (not that I need one!)

[Tafford]

Thanks for all your help. Fitted an exchange alternator (£44 + VAT IIRC) yesterday - took about 10 mins to get off and on - and all is well! Now even know that I should ignore the handbook regarding which warning light is which. Also took the opportunity to get a new drive belt whilst the other was off so have now have a spare.

POD - sounds like my car very similar to yours - ie warning lights in 'wrong' order, no 100A fuse, dodgy alternators etc...