[Mk2] [Turbo] Battery drain

[Doobie]

Hi guys, I've just bought my first MR2

She's a 91 plate, turbo 3SGTE.
Got a teething problem though, which isn't suprising as she's been stood for 2 years.

When I first gave her a bit of a poke she spat her dummy out Couple of dash warning lights came up;

Battery Drain
Engine Compartment Cooling Fan
Exhaust CAT temperature

Later when I tried to start her, the battery didn't have enough juice. I took the battery to get tested, and they confirmed it was faulty and I got a new one. This didn't clear any of the warning lights though, and the battery is continuing to drain.

I've checked the ALT SENCING and ECU-IG fuses, and both look fine.
The alternator belt is spinning when the engine runs.

What's the next step, a new alternator? Have a missed anything?

Thanks

[2mad]

I had some random dash lights come on when my alternator failed .. just a thought

[MR2 Turbo Boy]

I had some random dash lights come on when my alternator failed .. just a thought

+1 ...

[Doobie]

I had some random dash lights come on when my alternator failed .. just a thought

I was hoping it wouldn't come to that haha

[thomp1983]

Those lights are common signs of alternator failure but before you condem it do a few checks

Check auxiliary drive belt is present and not snapped or slipping
check alternator pulley is turning and not seized
remove 3 pin plug from alternator and with ignition on check you have 12v at each of the pins

If the alternator is turning freely and has 12v on all 3 pins then it's likely the rectifier has died a new one is about £20 and an easy diy fit.

If it's seized then water has got into the casing between the armature and casing and formed a layer of rust, you can dismantle and clean It all up but it's tedious to do and if you do I'd fit a new rectifier anyway

[Doobie]

Those lights are common signs of alternator failure but before you condem it do a few checks

Check auxiliary drive belt is present and not snapped or slipping
check alternator pulley is turning and not seized
remove 3 pin plug from alternator and with ignition on check you have 12v at each of the pins

If the alternator is turning freely and has 12v on all 3 pins then it's likely the rectifier has died a new one is about £20 and an easy diy fit.

If it's seized then water has got into the casing between the armature and casing and formed a layer of rust, you can dismantle and clean It all up but it's tedious to do and if you do I'd fit a new rectifier anyway

Brilliant mate, thank you! This was exactly what I was looking for, a £140ish alternator needs to be a last resort

[Gaz-32]

Hey guys jumping on the band wagon here. I also have my first mr2 but mine is an n/a I have the same issues but I've had my alternator tested and is giving correct readings I've also had my battery checked and is also giving a good reading but I bought a new and it's still draining the battery even more so when my lights are on.
I'll follow the guidelines given in this post but while I'm here could it be anything else if I'm getting good readings?

[thomp1983]

Hey guys jumping on the band wagon here. I also have my first mr2 but mine is an n/a I have the same issues but I've had my alternator tested and is giving correct readings I've also had my battery checked and is also giving a good reading but I bought a new and it's still draining the battery even more so when my lights are on.
I'll follow the guidelines given in this post but while I'm here could it be anything else if I'm getting good readings?

With the car running what voltage do you get at the battery terminals? What voltage do you get if you hold the revs at 4k?

[Gaz-32]

According to my battery test 14.16v loaded and 14.31v no load

[thomp1983]

Your problem sounds like a parasitic drain not a charging issue. First thing to do is get yourself a multimeter

[Gaz-32]

Your problem sounds like a parasitic drain not a charging issue. First thing to do is get yourself a multimeter

Already have one dude. What am I looking for and where? New to all this electrical fault issue business and I have to say I don't like it lol

[thomp1983]

http://m.wikihow.com/Find-a-Parasitic-Battery-Drain

That article covers what you need to do quite well, remember there's 3 fuse boxes, do unplugging the alternator last as I doubt it's your issue.

Does the car have an aftermarket alarm or stereo system fitted? Or anything else aftermarket for that matter such as a boost controller etc.

[Torero]

Nice one Chris, that's pretty useful.

[QUOC2008]

I had this problem... it was a bad earth wire...