La lancer with magna Bosch style alternator

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TRV28
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La lancer with magna Bosch style alternator

Post by TRV28 »

I have fitted a tn magna engine into my la lancer and all is complete except the alternator wiring is giving me trouble, I have used the magna alternator which is a Bosch style with regulator mounted on the rear of the alternator, I have removed the external reg from the lancer alternator setup (box which is mounted on right shock tower) and run single wire from yellow/black trace to the light wire on magna alternator, this is the same as how my other lancer appears to be wired, for some reason the light on the dash won't go out ,I believe it isn't charging but can't be sure as multimeter stopped working this arvo, has anyone else fitted a Bosch internal reg alternator to an early Mitsubishi with the external regulator alternator being original equipment? And if so, how did they wire it up?
1974 la lancer, 1993 gq patrol ute, 1971 Chevelle Malibu.
A112H
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Re: La lancer with magna Bosch style alternator

Post by A112H »

I did this on my Galant but I am pretty sure it was a solid yellow wire. But it was a Galant so no idea if it would be the same colour wire as a Lancer, lol
I really was no help there at all was I :(
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davetrees
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Re: La lancer with magna Bosch style alternator

Post by davetrees »

I run a 85A Bosch internal reg alternator off a Magna (from a TR, admittedly) in my GB.

There should be a plug with 2 wires on the alternator. One marked "L" goes to the alternator light wire in the loom. The other marked "S" goes direct to the battery, same as the main power cable does.
TRV28
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Re: La lancer with magna Bosch style alternator

Post by TRV28 »

That is what I have done but it isn't charging, the light comes on but won't go off when engine is running, the alternator was working in previous vehicle and my charging system was working
1974 la lancer, 1993 gq patrol ute, 1971 Chevelle Malibu.
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davetrees
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Re: La lancer with magna Bosch style alternator

Post by davetrees »

Sounds like the diodes in the regulator have blown ? Just get a new regulator pack put in it
TRV28
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Re: La lancer with magna Bosch style alternator

Post by TRV28 »

Is there a way if testing the reg to see if it is faulty? Are they overly sensitive? When removing engine and installing it the alternator may have been bumped but nothing major, the usual taps against radiator support panel that happens as an engine is craned from and into a vehicle, I also swapped pulley and I used rattle gun to remove nut but I held the alternator fan to dampen the rattling from travelling through the whole unit, the charge light only works when I connect alternator so I believe the wiring in the car is working, I did try to fit Bosch style alternator from a sigma to this car once before and it wouldn't work either, I figured the alternator was faulty and discarded it.
1974 la lancer, 1993 gq patrol ute, 1971 Chevelle Malibu.
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davetrees
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Re: La lancer with magna Bosch style alternator

Post by davetrees »

Are you sure it isn't charging (even though the light isn't going out) ? Put a voltmeter across the battery - once you get over about 1200-1500rpm it should show 14v or thereabouts. There could just be a fault in the alternator light circuit.

Maybe take the alternator to an auto elec & get them to test it. Regulators can just fail for no obvious reason .... they don't last forever.
TRV28
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Re: La lancer with magna Bosch style alternator

Post by TRV28 »

Ok I have tested the charge across the battery with the engine running and it is reading 11.2v this indicates I the alternator is not charging, I tested the circuit with a multimeter across the connection from alternator wiring(magna loom), and the plug from the lancer and I have a positive charge at the lancers plug, this says I should have appositive power source to energise the fields, I with run a Suiside wire once the car is running from positive battery pole and flick it across the wire on the reg and see if it energises the alternator, if not i will have to get it tested, the alternator is fairly clean and looks to be rebuilt only a year prior or so, I think if it is a fault it will be the reg, thanks for helping with this davetrees.
1974 la lancer, 1993 gq patrol ute, 1971 Chevelle Malibu.
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davetrees
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Re: La lancer with magna Bosch style alternator

Post by davetrees »

Something else to check ..... is the battery itself OK ? Make sure it is fully charged before doing your testing. Stuffed batteries can do strange things to charging circuits ....
TRV28
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Re: La lancer with magna Bosch style alternator

Post by TRV28 »

I have charged battery to full capacity on my c-tek charger, and it reads 12.8v, after I start car and run it with thermo fans off it sits on about 11.8v and slowly drops. If I put thermo fans on it drops quicker, I have pulled reg out and measured ohms across slip rings on armature and I have 130.k ohms, so I guess that means no broken windings and no shorts, the brushes in the reg are quite short and the resin in the back of reg appears to have been hot and melted slightly, I have bought another reg and will fit it tomorrow, hopefully thah will sort it, just seems coincidental that the reg stuffed up at precisely the same time I changed the alternator from one vehicle to the other.
1974 la lancer, 1993 gq patrol ute, 1971 Chevelle Malibu.
TRV28
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Re: La lancer with magna Bosch style alternator

Post by TRV28 »

Ok well I replaced the reg and the alternator is still not charging, I have double checked the wiring the wiring from the light and it has good connection and is giving a positive feed I have tested the battery wire and tested the the battery sense wire(blue) on the plug and they are all giving good signal, the light is coming on in the dash so this proves the reg is earthing, I don't have anything left to test and no more ideas on what could possibly be wrong with this alternator, only option left is possibly the alternator itself is faulty but as I said previously it was working fine in the other car. If anyone has another suggestion would be much appreciated.
1974 la lancer, 1993 gq patrol ute, 1971 Chevelle Malibu.
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davetrees
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Re: La lancer with magna Bosch style alternator

Post by davetrees »

Have you tried it with a different battery ?
2Lgalant
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Re: La lancer with magna Bosch style alternator

Post by 2Lgalant »

I did this with my galant I pulled the old external reg off just disconnect it leave it having the thick red wire onto the bolt bit with the nut on it and the yellow wire runs to the + of one of the plugs on the rear simple really
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