Engine running - no ignition / battery lights :yikes:

[911motorsport]

'94 pre-serp 4.3 BV Chimaera. Draining the battery dead in 4 hours!! On turning on ignition there is no battery or ignition light, but car starts and runs fine (bit spikey). Turn off and battery gets drained. Replaced battery with known good one; no difference. Any thoughts?

[GreenV8S]

Failed electronic module in the alternator, it's easily replaced.

[911motorsport]

GreenV8S said:

Failed electronic module in the alternator, it's easily replaced.

How?

please

Edited by 911motorsport on Sunday 13th July 09:33

[Ribol]

I would have said the rectifier has gone in the alternator.

Try disconnecting the alternator and see if it stops the drain.

[911motorsport]

Ribol said:

I would have said the rectifier has gone in the alternator.

Try disconnecting the alternator and see if it stops the drain.

good idea

[That Daddy]

Ribol said:

I would have said the rectifier has gone in the alternator.

Try disconnecting the alternator and see if it stops the drain.

[911motorsport]

well, I've removed the alternator with a mind to replacing the whole unit. How much should I be looking to pay? Marelli A127-65 STC 223

[GreenV8S]

911motorsport said:

well, I've removed the alternator with a mind to replacing the whole unit. How much should I be looking to pay? Marelli A127-65 STC 223

I'd guess around £100 for an exchange unit. If you didn't mind getting your hands dirty you could replace the electrics module for a fraction of the cost, but you would need to dismantle the alternator to do it. It is up to you to decide whether that job is within your abilities.

[911motorsport]

I stripped the alternator down but could find nothing obviously wrong (fixable). So I have replaced with a new one.

I thought I would post a link to help anyone else looking to get a replacement alternator. Pre serp alternator part no is STC 223 for Magnet Morelli. 65 AMP unit. These are available as a straight out purchase at £57.00 for a brand new pattern one. From here: http://www.alternatormart.co.uk/. Freindly and a bit of a TVR fan :-)

This appears to have sorted the problem with one possible exception. I cannot recall if all three tell-tale lights between the speedo and rev counter come on and then (hopefully) extinguish. When I turn on the ignition just the bottom and centre ones light up (1 red 1 yellow) and then go out once the engine is running. Is that right, or do I still have a problem?

Also, whilst on matters electrical: The car has been running rich so I bought a couple of lambda sensors. On replacing the old ones I found one of them to be finger tight!! I thought I'd heard a bit of blowing from around there Again, I mention it in case it's something worth checking from time to time (lot of expansion and contraction there).

And finally! I have bought a Mallory high output coil. It mentions the requirement for a ballast or loom resistor to be present. It says most modern cars have one. Is there one fitted to the Chimaera?

Any help would be greatly appreciated!

Edited by 911motorsport on Thursday 17th July 23:00

[GreenV8S]

911motorsport said:

I have bought a Mallory high output coil. It mentions the requirement for a ballast or loom resistor to be present. It says most modern cars have one. Is there one fitted to the Chimaera?

Not as standard.

Some of these uprated coils also require an uprated ignition amplifier. If this one doesn't then it probably isn't much different to the original coil apart from being the wrong impedance.

There isn't much point uprating the coil unless you have forced induction or LPG. Once you have enough of a spark to ignite the mixture, adding more gives no benefit. And if the standard setup isn't working well enough to do this there's something wrong with it.

[911motorsport]

Thanks Peter. The only reason I got the uprated coil is because someone was going the Emerald route and selling off their surplus bits. Among those bits was a nice shiney chromed Mallory coil. The existing coil on my car looks old and past its sell by date, plus I've experienced occasional nmisfiring under load. It is quite tuned up in that it is the Big Valve 4.3 with H218 cam Tornado chip. Magnecor leads.