New alternator
#1
01-24-2018 | 04:09 AM
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From: Armidale
New alternator
Just a quick question before I spend hours reinstalling a new alternator. Generic brand supplied as replacement has different terminals but I have that sorted. But on the old alternator the was a radio suppression capacitor but I have no idea which terminal it is connected to or if the new alternator does in fact need one. Obviously the case goes to ground but does the other lead go to battery power or the ignition light terminal.
Thanks in anticipation.
Col
Thanks in anticipation.
Col
#2
01-24-2018 | 05:07 AM
Joined: Mar 2015
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From: Dural, Northwest Sydney. Australia.
#6
01-24-2018 | 10:41 PM
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From: Armidale
OK, not happy Jan, just spent heaps of money on a new alternator and lots of hours installing same and nothing has changed with the problem. So much for auto electronicians. The battery light(ignition light) has a faint glow and with the revs it increased in brightness. Auto spark said the regulator was shot and I could not source one. Anyway the problem persist, 12.4 v at battery and 14.7 with engine running but the light refuses to go out. Tried loading the circuit with lights etc to no avail. Anyone out there that can make my Australia Day better with a fix?
Desperate Col
#7
01-25-2018 | 09:07 AM
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#8
01-25-2018 | 01:10 PM
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From: Armidale
Jagcad, consider the temperature share although if it takes as long as the Christmas card sent from Canada, which arrive last week, don’t hold your breath!
Australia Day celebrations today so driving the MG midget an hour or so away, so chasing the connection will have to wait until later. I suspect the joint on the firewall/ baulkhead but further test will continue.
Col
Happy Australia Day to all In Oz.
Australia Day celebrations today so driving the MG midget an hour or so away, so chasing the connection will have to wait until later. I suspect the joint on the firewall/ baulkhead but further test will continue.
Col
Happy Australia Day to all In Oz.
#9
01-27-2018 | 05:26 PM
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From: Armidale
OK now for the hard part!!! Does anybody know the route that the brown / yellow signal wire from the alternator to the warning light? It should be simple to physically follow one lousy wire but I can’t see well enough to trace it. Removed,cleaned and tightened the power wire back to the battery, bulkhead connection and I am sure that that side is perfect.
New alternator charging at 14.1 with good battery(new) but the warning light refuses to go out. Anyone know the route or any other ideas?
New alternator charging at 14.1 with good battery(new) but the warning light refuses to go out. Anyone know the route or any other ideas?
#10
01-27-2018 | 06:03 PM
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Speaking from Series III experience.....
The 'excitor' wire to the warning light is brown/black and travels in front of the engine...right where the cylinder head and block come together. The downwards towards the distributor, then over towards the RH wall of the engine bay. Various other wires join it along the way (oil pressure gauge and light, a/c compressor, and so forth). They terminate in a rectangular multi-plug. The mating plug and harness is down low on the RH engine bay wall, just forward of the wheel area.
Wire breakage is common in the regions where the wires are very close to the engine. They're thin gauge and years of baking takes a toll.
Cheers
DD
The 'excitor' wire to the warning light is brown/black and travels in front of the engine...right where the cylinder head and block come together. The downwards towards the distributor, then over towards the RH wall of the engine bay. Various other wires join it along the way (oil pressure gauge and light, a/c compressor, and so forth). They terminate in a rectangular multi-plug. The mating plug and harness is down low on the RH engine bay wall, just forward of the wheel area.
Wire breakage is common in the regions where the wires are very close to the engine. They're thin gauge and years of baking takes a toll.
Cheers
DD
#11
01-27-2018 | 06:50 PM
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From: Armidale
Thanks Doug, now one more. If the exciter wire just goes to the warning light which has 12+v then if I take a wire directly from the alternator to the battery though a test lamp shouldn’t the alternator behave in the same way as if it was connected to the lamp in the car. Of course the test lamp will be illuminated as soon as connected to battery rather than the ignition switch and should it not go out if the alternator is charging. The battery is receiving charge with either the car wiring or the gerry rig as it is still being excited? Does the small lamp in the car make the difference?
Any help appreciated as I have followed the wire to plug on the fire wall and can not see any problems.
col
Any help appreciated as I have followed the wire to plug on the fire wall and can not see any problems.
col
#12
01-27-2018 | 07:54 PM
Joined: Feb 2010
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From: Adelaide Stralia
Engine earth strap fiasco is also a must check when tracking electrickery in teh Series cars.
Our S2 V12 did that, and drove me more silly than normal. Everything was working, NO flat batteries, bright lights etc, so I pulled the bulb in the dash and moved on.
Always had that issue on the "to do" list, never got back to it. Care factor from the car, ZERO.
Probably NOT the answer you answer you want, but we are different way down here.
BUT
On the XJS I had the same, and eventually found 3.5v in that exciter wire with the Ignition OFF, OOPS. Ignition switch electrical section dismantled and cleaned, all sweet after that.
Our S2 V12 did that, and drove me more silly than normal. Everything was working, NO flat batteries, bright lights etc, so I pulled the bulb in the dash and moved on.
Always had that issue on the "to do" list, never got back to it. Care factor from the car, ZERO.
Probably NOT the answer you answer you want, but we are different way down here.
BUT
On the XJS I had the same, and eventually found 3.5v in that exciter wire with the Ignition OFF, OOPS. Ignition switch electrical section dismantled and cleaned, all sweet after that.
Last edited by Grant Francis; 01-27-2018 at 07:57 PM.
#13
01-27-2018 | 08:38 PM
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From: Pacific Northwest USA
Thanks Doug, now one more. If the exciter wire just goes to the warning light which has 12+v then if I take a wire directly from the alternator to the battery though a test lamp shouldn’t the alternator behave in the same way as if it was connected to the lamp in the car.
Yes, I'd say so. You're just making a duplicate circuit with your test light.
Of course the test lamp will be illuminated as soon as connected to battery rather than the ignition switch and should it not go out if the alternator is charging. The battery is receiving charge with either the car wiring or the gerry rig as it is still being excited? Does the small lamp in the car make the difference?
My experience is that, without 'excitement', an alternator will still work.....if it reaches a high enough RPM. Exciting the alternator is what allows it to charge a idle speeds. That's my understanding, at least.
The small lamp provides resistance. How resistance serves to excite the alternator....I don't know.
Cheers
DD
#14
01-27-2018 | 09:13 PM
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From: Armidale
Thanks again, earth strap is ok but ..... I traced the brown /yellow back to the firewall and tried to check the whole length and no faults found. If I take the wire of the exciter by removing the bulb surely it won’t charge at idle?Have to live with it until I get my annual rego check tomorrow. Knocked the wire off the oil pressure gauge while checking but that was an easy job. Here hoping it passes with an ordinary handbrake. Looking like I might have to take it off the road and give it a Birthday makeover!
Col
Col
#15
01-29-2018 | 05:29 PM
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From: Armidale
Finally all is right with the world. Short version there was no instructions with the new alternator so I asked the supplier and they told to me to connect the large terminal
Yahoo all is right with the world. The new alternator did not come with diagram of connections so I rang the supplier and was told to connect the battery wires to the large post marked B+ and the ignition light wire to the other post marked W+. It charged but the ignition light stayed on,same symptoms as the old alternator. As the post continued I had run out of ideas. Finally saw another auto electrician who looked up the connections in the manufacturer’s book and W+ is the centre of the stator windings. This produces volts for the tachometer on some models.
Switched the wire to another spade next to the large spade in the “plug” terminal and all is corrected.
Thanks for those who helped and I hope that this post might help someone else.
Also fixed the leaking exhaust and got the rego. inspection certificate so with the handbrake pads next on the list I am going to have a break from machanical work for a while.
Col
Switched the wire to another spade next to the large spade in the “plug” terminal and all is corrected.
Thanks for those who helped and I hope that this post might help someone else.
Also fixed the leaking exhaust and got the rego. inspection certificate so with the handbrake pads next on the list I am going to have a break from machanical work for a while.
Col
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