It's possibly the belt being loose?
MR2s are notorious for eating alternators. I've had 9 failures in 7 different ways over 14 years. First one wore out, second one bust a diode then the third one has had many failure modes. It's now got worn bearings that need replaced.
Alternator or other issue?
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This area is dedicated to technical discussions concerning SW20's. Please try to spell correctly because this will help people find information later if they are using search functionality. If you need assistance with your car and want to host a spanner day, please use the appropriate section of the forum: http://mr2.org.nz/phpbb3/viewforum.php?f=35 Thank you.
- GDII
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Re: Alternator or other issue?
1990 SW20 MR2 G-Limited (GEN4 3SGTE Installed)
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
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Re: Alternator or other issue?
I suspect mine is down to user failure, I.e dripped some oil while doing an oil change a couple of weeks ago ..
I'm going to do some basic diagnostics tonight when I get home from work.
I'm going to do some basic diagnostics tonight when I get home from work.
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Re: Alternator or other issue?
Cleaned up a couple of grounds at the rear. Checked the 7.5v fuses fromt and back.GDII wrote: ↑Thu Aug 04, 2022 4:04 pmIt's possibly the belt being loose?
MR2s are notorious for eating alternators. I've had 9 failures in 7 different ways over 14 years. First one wore out, second one bust a diode then the third one has had many failure modes. It's now got worn bearings that need replaced.
So I charged the battery up to 12.4v ignition off.
Started the car and the voltage drops to 11.9v @1400 rpm.
Revved it a few times no increase in voltage. Put lights on etc and it went down to 11.8x volts.
I wasn't fully able to unplug the 3 pin oval from the alt as I just couldn't get it out to test each pin.
So I'd say having read up on the subject it's 30/70 % either the middle wire or a new alternator time...
- GDII
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Re: Alternator or other issue?
I'd say new alternator. 9 out of 10 times it is.
1990 SW20 MR2 G-Limited (GEN4 3SGTE Installed)
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
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Re: Alternator or other issue?
You know what's weird, I charge my car battery to 12.7v (checked with multi meter).
And I leave charger plugged in and I turn on my ignition but don't start the engine.
I get the hotcat sensor light and the battery discharge symbol.
But if the car isn't running, of course the alternator isn't running so why wpuld these lights even come on? Does this indicate a wiring issue somewhere as to my simply mind wouldn't they only be an error when idling due to low voltage?
And I leave charger plugged in and I turn on my ignition but don't start the engine.
I get the hotcat sensor light and the battery discharge symbol.
But if the car isn't running, of course the alternator isn't running so why wpuld these lights even come on? Does this indicate a wiring issue somewhere as to my simply mind wouldn't they only be an error when idling due to low voltage?
- GDII
- Forum Moderator - MR2OCNZ
- Posts: 5741
- Joined: Sun Jul 10, 2011 5:13 pm
- Stomping Ground: Wellington
- Prime Mover: SW20
- First name: Phill
Re: Alternator or other issue?
Those lights go on because the alternator is not charging because the engine is not running. It's normal.
If the engine is running and they are on the alternator is definitely not charging.
If the engine is running and they are on the alternator is definitely not charging.
1990 SW20 MR2 G-Limited (GEN4 3SGTE Installed)
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
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- Guest of the Club.
- Posts: 6
- Joined: Thu Aug 04, 2022 8:24 am
- Stomping Ground: Bay Of Plenty
- Prime Mover: SW20
- First name: Nick
Re: Alternator or other issue?
Update; new Alternator fitted and problem is now fixed.
- GDII
- Forum Moderator - MR2OCNZ
- Posts: 5741
- Joined: Sun Jul 10, 2011 5:13 pm
- Stomping Ground: Wellington
- Prime Mover: SW20
- First name: Phill
Re: Alternator or other issue?
Excellent.
1990 SW20 MR2 G-Limited (GEN4 3SGTE Installed)
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/