Bad Alternator on '99 Esprit....Perhaps ??

[ScottRUSA]

I recently purchased a used 99' Esprit with 22k miles, here's the latest saga after driving it all of 9 times since I received it.......

Last weekend I noticed the Alternator, ABS and Air Bag Warning (tell tale) lights coming on so I checked the condition of the battery and noticed it was an old Audi Battery without any date information on it. Members of the US Yahoo Esprit group suggested the faults (warning lights) were either caused by a bad battery (needing a new one) or the Alternator was going bad (said it was a typical problems after two years of normal use) so I took a chance that it was the battery. I simply went and purchased new battery, installed it, plus I've been putting it on a trickle charger (slow charge rate) at night. I have to admit, although I wrote technical manuals for the US Navy I found Changing the battery with the very un-clear security system concerns (documented in the driver's manual) was a challenge in itself.

Well, after changing the battery the Alternator, ABS and Air Bag warning lights went out but this morning as I was headed out for a ride the Engine Warning light came on..... So I continued for a short drive (according to the manual, if it's not flashing, it's a minor engine fault), the engine light remained on and 30 minutes into the drive the RMP gauge was oscillating from 0-3500 (even after putting the car in neutral and stopping by the side of the road) and so too was the MPH gauge oscillating, indicating a nice 80MPH whilst also stopped and idling. So here I sit writing another note, if anyone has any
suggestions I'm all ears, but until I have some sore of a clue, perhaps something simple like a bad module or maybe because the alternator is bad it affects the electrical system, etc., the car will remain in the garage. Note this car has not seen rain or a car wash, i.e., no moisture problems.

[ErnestM]

Engine Warning light = bad juju (blinking or not). Take it to a Lotus dealer and let them put it on the machine...

...Have them test your alternator as well for piece of mind (unless you've already used the a.start car b.pull battery cable technique)

ErnestM

[MikeyRide]

I understand that the battery warning light does not go on until a pretty low (useless) voltage. Run the car and check the battery directly.

When Dave Hsu's alternator died (I think it was 3 years old at that point), the check engine light came on and the scanner gave the emissions error that fires when the fuel cap is loose. 3hrs later the car was dead at the side of the road.

[cnh1990]

In absense of a stabilized voltage source the ECU will do strange things. If driven in that condtion the sensors will give flase reading and the engine will backfire and do strange things. If the diodes of the alternator go out it may actually discharge the battery instead of charging it.
Calvin

[lotusman]

Since you only have an idiot light for determining whether the alternator is working, do this. With the engine off, check the voltage across the battery terminals, it should be about 12.5 volts. If not, charge it, preferably out of the car. Reinstall, then start the car. Check the voltage again across the terminals, it should be no less than 13.3 volts and preferably 13.5. Although I have a voltmeter gauge, the warning light comes on at anything less than 12.5 volts. (Most current auto battery idiot lights though only come on when the alternator belt breaks.) If not greater than 13.3v, it is probably the voltage regulator. I have put three of them in my '89. I have a Valeo alternator(original equipment) and the regulator screws on the back. However, one melted itself into the brushes of the alternator and I needed the alternator rebuilt, $135.

And yes when the battery gets really low, all the warning lights come on.

About the other problem, the tach and speed gages jumping all over while standing still and the car running awfully rough. I think? This may be that voltage problem. However, my answer to that problem though was the computer. The computers have been known to fail due to high voltage pulses. Changed the box(Autozone) for about $80, reinstalled the Chip box and no more problems. After you fix the alternator problem, then address the gauge problem

Hope this helps,
Lotusman
'89 non-SE

[hantsmale]

I had this same problem on my Esprit V8, and it turned out to be the alternator.

Had it replaced, then a month later it went again, so replaced again! Been OK since. Just need new clutch now ;-)

[Lotusman]

So, Hantsmale. Did THEY give you a free replacement alternator? What did THEY say was wrong? How did THEY say it failed? What brand was it? And ScottR, has any of this corrected your problem? Feedback is the only way to increase knowledge. Please let us know!
Lotusman
'89 non-SE