11AC Alternator problems

B

BobTaylor

Member
Hi, My alternator is not charging. I have tested the voltage on the battery without the engine running, then with the engine running and there is no change.
I have replaced the 4TR Regulator and cleaned and checked the connections, no joy. I therefore assume that the alternator is not working. I was allegedly reconditioned a few years ago before I owned the car !! So there would seem to have been issues before.
I have placed a post in the 'wanted' section, but can anyone recommend a supplier for a new or reconditioned unit?
OR is it possible to fit a later type of alternator, though I guess this must involve some rewiring (not my strong point)
Bob
 
roverp480 said:
AES do a replacement if you want to go down that route Lucas 11AC Alternator
The Lucas ACR type is readily available only about £50, but as you say a rewire required although not too difficult
Wadhams do an 11AC J R Wadhams Ltd | Alternator 11AC: 3500
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THanks, I see that Wadhams want the old one first, which is a pain, for recon items most people charge a surcharge until you send the old one back. I will get in touch with AES on Monday, I think I would prefer to pay the extra for a new one, I looked at the pics on the site and the rear seems to have a different number of wires and connections though.
Cheers
Bob
 
hi I had mine recond for a reasonable amount (new slip ring soldered in and lathed and new brushes).
Unfortunately while half assembled on my garage floor I pushed the car wheel into it and buckled the winding.
I took it back to the my auto electrical guy and he replaced the winding and reassembled and cleaned it up.
He had parts avail locally, so lucky me ( great service in our little town of Thames on the Coromandel)
I wanted to keep my 11ac without a rewire. :)
 
My ignition light was always on, so I thought the alternator was faulty. I changed the 3AW regulator for the ignition warning light and it now goes out when you rev the engine, but eating the battery with my multimeter seems to show the battery is not being charged when the engine was running, the meter reading is the same with or without the engine running!! Can the sign warning light operate correctly but the alternator still not charge the battery?
I have traced and cleaned all the terminals junctions etc from alternator back to battery including the junction under the carpet in the drivers footwell.
One bonus is that I seem to have cured my intermittent starter motor problem, the post in the solenoid had a loose nut for one of the wires to the starter/alternator. Tightening that has fixed the starting!!!!
Can anyone suggest any other checks I can do before removing the alternator?
Bob
 
Hi, You've checked the power connections, have you checked the earth connections? Not just the battery and engine earths but the control boxes earths.

Colin
 
Worth checking all the connections in the alternator circuit including the separate ones to the steering column lock. It sounds like the alternator is not exciting to produce current , which could be the brushes or any of the connections in the circuit. With the ignition on , but engine not running, are you getting battery voltage on brown /blue wire to the 4TR, ?
 
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roverp480 said:
Worth checking all the connections in the alternator circuit including the separate ones to the steering column lock. It sounds like the alternator is not exciting to produce current , which could be the brushes or any of the connections in the circuit. With the ignition on , but engine not running, are you getting battery voltage on brown /blue wire to the 4TR, ?
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Hi, have checked the brown/blue wire as you suggested, all ok. I have also checked the 2 wits that go from the alternator to the regulator for continuity, all ok there too.
The alternator is a recon unit from Wins. I am now running out of ideas!
 
I have just re checked all the connections including earths and all seems ok. I have just re-checked the voltage on the battery it is 12.2V without engine running (normally 12.4 when fully charged!) and with the engine running with enough revs to extinguish the charging light the voltage is actually less at 12.04 V !!!!! I guess that means that there is a drain on the battery from the internal light, clock and ignition system and obviously nothing going from the alternator.
Can anyone suggest what to try next ?
Bob
 
PROBLEM SOLVED !! The battery has never charged since I got the car a few weeks ago, it turns out that someone had wired the main lead from the alternator back to the solenoid on to the wrong terminal. It was connected to the starter motor terminal instead of the battery terminal. Swapped over and all is fine. battery charges at 14.6V , ignition light goes out instantly . Anyone looking for an 11AC alternator !!!!!!
At least now I can put some miles on the car and not have to worry about getting a flat battery.
Thanks to all who offered words of advice.
Bob
 
BobTaylor said:
PROBLEM SOLVED !! The battery has never charged since I got the car a few weeks ago, it turns out that someone had wired the main lead from the alternator back to the solenoid on to the wrong terminal. It was connected to the starter motor terminal instead of the battery terminal.
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It was charging while you were cranking the starter.....

Not a lot of good, but it all helps!o_O
 
I was having issues with the 11ac setup in my 1971 P5B. Every component with the exception of the alternator has been replaced. In the end issue was a damaged earth wire from the regulator at the earthing point under the bonnet hinge.
 
Unfortunately the issue is still not fully fixed! It is working 98% of the time but the ignition light still comes on and ammeter falls below zero when coming when at lights with car in gear ... Put her into neutral and issue resolves.
 
Sounds like you have a very low idle speed, and stationary in gear reduces the engine speed just enough to put the ignition light on. I'd say the lower the idle speed the better, and live with the ignition light coming on, but if you can't then just tweak the idle speed upwards a bit and see if it cures your problem. If it does then you can make an informed decision about which way you want to go.
Some engines will idle right down much lower than they need to and your car might be one of those, plus a weak mixture will increase the drop between idle speed at rest, and in gear.
 
I concur with the above. As a matter of interest does the drivers handbook give any indication about the operation of the warning light .
My 1990's Land Rover handbook for the 90/110 fitted with an 16 or 18 ACR, mentions the light may come on at idle but as long as it extinguishes when revs are raised it is satisfactory. The 11AC is a fairly unsophisticated alternator set up compared with modern cars and I would agree, live with it or increase the idle speed a touch.
 
DubP5B said:
Unfortunately the issue is still not fully fixed! It is working 98% of the time but the ignition light still comes on and ammeter falls below zero when coming when at lights with car in gear ... Put her into neutral and issue resolves.
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harveyp6 said:
..., plus a weak mixture will increase the drop between idle speed at rest, and in gear.
Click to expand...

Indeed, i suggest that you check your mixture strength at idle, and if you find that you have a reasonable margin to enrich, you should do so. In this way the idle speed drop between neutral and in gear will be less pronounced.
 
So it was left in today he said it was running too rich and he reduced the mixture a tad. She is now driving like a dog and stalling. Have to pump the accelerator to get her to move from stationary. She did 200 miles last weekend so would guess the electronic ignition hasn't been damaged by the dodgy earth ?
 
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