Bat light on, No mivec

[Gelo]

Good day! I'm new to this board and hoping that fto owners can help me out.

I have a mirage coupe fitted with a 6a12mivec engine. Problem is that my battery indicator is on, I have changed my alternator 8 times already with 3 reconditioned and the 5 others are surplus alt. with same part number(md317515)
The engine doesnt hit mivec unlike before revving upto 8250, it limits upto 5,500.(so no sweet music for me for the past year )
My mechanic said that the alternator is not the culprit as we have changed it so many times and also the battery is charging, even tried to disconnect the neg terminal while idling and the engine does not cut off. Tested charging and 14v but he said that the charging does not cut off... The battery is not draining and I have used the car for long trips without any problems even if the bat indicator is on. Acceleration is still the same as before except for the mivec not engaging.

Was wondering what are the other things to look at aside from the alternator that limits my engine and bat indicator remained lit. It's been almost a year of frustration of trying to find out what the cause of it. I have just used my car again after 4 months keeping it garaged because i hate driving it knowing somethings wrong with it. Checked the 80a fuse and relay all are fine.
Just another info that might help... I have my battery located at the trunk, this is since i have the mivec swap and no problems before this happened. Hope you guys can help me out as I'm really frustrated and about to give up on this problem.

Thanks much!

[Aido C]

Are you sure these 2 problems are related? Did they both happen at the same time?

[colm_mcm]

The 4 pin Alternator has 2 pins on it that activate the MIVEC and 2 that charge the battery,
You need to use a 4 pin Alternator from a GPX as opposed to a 2 pin from a GR/GX.
Maybe the wrong alternator is being used?

[Kace]

The 4 pin Alternator has 2 pins on it that activate the MIVEC and 2 that charge the battery,
You need to use a 4 pin Alternator from a GPX as opposed to a 2 pin from a GR/GX.
Maybe the wrong alternator is being used?

Good point - it definitely sounds like the alternator from the symptoms, however if the thing has been changed 8 times it's hard to believe that of the 8 alternators, some were not GPX ones.

[jayod12b]

Had the same problem myself for almost a year,
Alternator went got it reconditioned by a local guy
Charged perfectly 14v all the time but when i got to 5,500 rpm it limited and no mivec

Went back to auto eletrican and he didnt want to hear about it cause it was charging perfectly
Looked into it on different sites and found out that the diode pack in the 4pin model that he had replaced had to be a special one to activate the mivec

So in the end bought a new one on ebay in the uk fitted it and she started to sing again
But it did wrecked my head for ages

[Muad_dib77]

Had the same problem myself for almost a year,
Alternator went got it reconditioned by a local guy
Charged perfectly 14v all the time but when i got to 5,500 rpm it limited and no mivec

Went back to auto eletrican and he didnt want to hear about it cause it was charging perfectly
Looked into it on different sites and found out that the diode pack in the 4pin model that he had replaced had to be a special one to activate the mivec

So in the end bought a new one on ebay in the uk fitted it and she started to sing again
But it did wrecked my head for ages

Did you get a new diode pack on a new alternator?

[Gelo]

thanks for the replies!

Anyway, here's how it started. I just had a carwash that time then on my way home the bat light was on but dissapears at 3k rpm.. the next day it stayed on already any rpm and the noticed that the horns and electrics were about to fail. So I had it recon, after installing the newly recond alternator, the bat light is still there but this time it was perfectly charging. tried to spin around for a test and realized mivec not engaging. So i was confused that time and had it recon on another shop yet its still same. got a surplus 4 pin alternator-md336780 2pcs, still did not work and by research this one is a 4 pin for a gr model. So I got the exact alternator md317515, sorry for not mentioning the other alternators I got... I also had three md336781 alternators used which is also a 4pin for a mivec unit. Still no change, bat light is still on. Im really frustrated at this point. the bat light is brightly lit up once i start the engine and turn on the aircon and lights, it reduces its brightness when i rev it but its still there.

Any more culprit that I can check? Is this somehow connected to a problem in ignition as well? wires are checked and its all good. This bat light puzzle is really giving me and my wallet a big headache

Hoping you guys can share some more info on this problem as I know you're more knowledgeable as yours are the real thing(FTO, I mean)

[CJ]

I also had three md336781 alternators used which is also a 4pin for a mivec unit.

This is a 100W alternator i.e. the best of the bunch (the others are 75A and 85A), suggest you use this one (you should be able to make up one good alternator from all of your spares!). Make sure the rectifier is working correctly before fitting....

CJ

[Bernard]

I'm not sure if it's possible with it being an engine swap but if you can run a diagnostic and see what (if any) error codes are returned.

[Gelo]

I also had three md336781 alternators used which is also a 4pin for a mivec unit.

This is a 100W alternator i.e. the best of the bunch (the others are 75A and 85A), suggest you use this one (you should be able to make up one good alternator from all of your spares!). Make sure the rectifier is working correctly before fitting....

CJ

will try to bring it at a alternator shop to check them and will try to fit it again and see how it goes...
however, with so many changing of alternator(which is a pain as my mechanic is about to get crazy changing alternators for my car ) I'm really thinking that it' not the alternator that's causing the bat indicator to turn on.

Bernard,
haven't tried it since this problem occured , but I have tried it along time ago with a mitsu service dealer here when i swapped the engine. Will go this week to a mitsu service to try and check error codes... thanks for the heads up!

[Bernard]

You shouldn't have to go to a dealer to check for error codes, search the forum for Diagnostic and you'll get a load of results.
It's an easy process that only takes a few minutes (probably).

[colm_mcm]

Battery light & no MIVEC has to be alternator related.

[Gelo]

You shouldn't have to go to a dealer to check for error codes, search the forum for Diagnostic and you'll get a load of results.
It's an easy process that only takes a few minutes (probably).

I'm a bit afraid of trying it as i might burn some wires
not really good in doing it myself....

I'll have the alternator wirings checked again once i get off from work... will try to bring it to a lifter so to see if some wires underneath are disconnected..

any more suspect regarding my tiring problem would be very appreciated!
Thanks alot!

[Kace]

Honestly - do the diagnostic yourself first. Do a search on here for instructions.

You can't mess this up or damage / fry anything and it only takes about 10 mins.

[Gelo]

update: just changed again the alternator(md317515)
mivec is now working and charging is good, but still the bat light is still on.
I was messing around the fuse box inside the car(junction block), i don't know what its called bbut when i pushed the
beside the fuse box, the one connected on its side white square one, the bat light went off but then it came back, had
another push it went out again but it came back...i feel theres something loose or broken around that area...will have
an auto electrician check it out tom. checked the manual, it says its the Body wiring harness and instrument panel wiring harness combination.... any idea what that litttle box is? is says something like 12.5v 5 bulb etc...



thanks

[Gelo]

Just want to update with this problem that I had.
Turned out that the wires for the alternator socket were placed on different pins. Since the engine bay was so tight and have to remove the axle just to get the alternator out, the first mechanic that got to my car probably have pulled out the wires and just placed them back without checking which color goes to the pins. 3 wires were altered. Damn! After all those alternators I got and labor. My trusted mechanic told me that it has something to do with the electrical and not the alternator anymore. It just so happens that it's really difficult to find a trusty electrician around till I found one haha! All the time I never really thought of checking that one since the wiring at the socket looked good...

So in any case of you mivec owners having problems with bat light with no mivec, but charging is good. You might also want to check your 4 pin wire socket just in case.

thanks for all the advises!
Missed that MIVEC roar! So happy to hear my engine sing again!

[Sebastian]

glad u sorted .
loads of cowboys out there grrrrrr