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I like the way you're thinking Mykey
And it's not the other way around where you got a replacement alternator that was specified for the original car with a +ve earth and you've fitted it on a converted car with a -ve earth?
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'powdering' of alternator belts...
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B
Barry White
All lucas 16 and 17 ACR are -ve earth and I can confirm the small spade conection has no other funtion other than illuminating a test lamp and the unit will funtion without it conected.
the other 2 large spade connectors are the 12+ volt output and connect directly to the battery via the solenoid (in later years by a fusible link or recently a fuse)
A simple test of the rectified pack is remove the belt and spin the alternater pulley by hand (while it is still connected) it should spin free if the pack has gone you will feel a pulsing resistance
the other 2 large spade connectors are the 12+ volt output and connect directly to the battery via the solenoid (in later years by a fusible link or recently a fuse)
A simple test of the rectified pack is remove the belt and spin the alternater pulley by hand (while it is still connected) it should spin free if the pack has gone you will feel a pulsing resistance
I like the way you're thinking Mykey
And it's not the other way around where you got a replacement alternator that was specified for the original car with a +ve earth and you've fitted it on a converted car with a -ve earth?
Actually that would be JUST like my vendor to supply such an item and not know it themselves - but I'm thinking that minis left the realm of "positive-earth" when they made the leap to alternators from dynamos in the late sixties. The online parts catalog doesn't show any options for alternator polarity, anyway.
B
Barry White
The leap to negative earth was to do with galvanic corrosion and dynamos output either you just flashed the field terminal to polarise it.so negative earth dynamo cars preceeded alternaters (but this aint solving the problem)
Interesting...gonna try the hand-spin test ASAP.
But as to that small-terminal connection: truly, this is not required for the alternator to charge? I thought that kind of alt function was possible - but only in alternators called something like "one-lead" or similar. (I think I once rebuilt an American alternator with a very simple retrofit kit that worked thusly - just one connection plus mechanical ground, and it was good to go.)
--Dave
B
Barry White
Cut the fault in half by removing the leads from the alternater (insulate securly) then run the engine and see if the belt squeels or powders)
If all runs smooth its unlikly to be a mechanical/belt problem
Then make up 2 cables run one from the earth on the alternator to the earth cable from the battery. the other from the large spade connector to the +ve side of the battery cable (use 8gauge wire) start engine if all connections are secure you should have 13 to 14 v at the battery if not the unit is goosed.
Ps did you try this i mentioned earlier A simple test of the rectified pack is remove the belt and spin the alternater pulley by hand (while it is still connected) it should spin free if the pack has gone you will feel a pulsing resistance
If all runs smooth its unlikly to be a mechanical/belt problem
Then make up 2 cables run one from the earth on the alternator to the earth cable from the battery. the other from the large spade connector to the +ve side of the battery cable (use 8gauge wire) start engine if all connections are secure you should have 13 to 14 v at the battery if not the unit is goosed.
Ps did you try this i mentioned earlier A simple test of the rectified pack is remove the belt and spin the alternater pulley by hand (while it is still connected) it should spin free if the pack has gone you will feel a pulsing resistance
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...just try a 2 ish watt lamp,wired from 12v,and connect the other side to the charge indicator terminal,via a female lucar connector.
It should take 10 minutes,and will confirm two facts,regarding your issues.
If you were down the road,i would come and do it tonight! :icon12:
*cannot believe it,i still have my old,paper notes on alternator testing,taken from original Lucas workshop procedure.
It clearly states,"voltage should be present,at charge warning terminal,engine off,igniton on"
This is present due to above^ wiring. I have an old Coventry Climax stacker,which has an acr alternator,and stops charging,when the charge lamp fails.
It should take 10 minutes,and will confirm two facts,regarding your issues.
If you were down the road,i would come and do it tonight! :icon12:
*cannot believe it,i still have my old,paper notes on alternator testing,taken from original Lucas workshop procedure.
It clearly states,"voltage should be present,at charge warning terminal,engine off,igniton on"
This is present due to above^ wiring. I have an old Coventry Climax stacker,which has an acr alternator,and stops charging,when the charge lamp fails.
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Mykey - thanks for all the pointers. I just tried the hand-spin test - no resistance felt (key on & connector in place, right?)
The other test (bypassing existing leads) seems unnecessary to me, though I'd do it anyway if I had a quick-disconnect female terminal of that large (1/2" or so width) size needed - without that, all I have is tiny jumpers that can't handle much current. Anyway, DVM tells me that the stock connections are getting full battery voltage, and have been all along. Same testing tells me alt earth is excellent as well, so I don't now see the point in creating substitute test connections, although it's nice to know it's as simple as making up one hot-lead.
No, the squeal never occurs when the connector is disconnected. I was tempted to conclude that this points to an electrical problem, but I suppose it doesn't entirely rule out belt issues (though I have no concern about that really being the problem at this point.)
I'd rebuild my two old alternators (both of them higher output than the new one, which at this point I really want to condemn 'cause...well, it's got ZERO output) but it looks like the separate rectifier/brush and diode assemblies would cost 3/4 of what each complete alternator would.
Specialty shop tested my old one, and told me yesterday that diodes are shot, and that this is typical of overworked alt trying to charge a bad battery. How crazy would it be to test/replace diodes right on the board? Seems to me diodes are cheap, and I've no problem soldering...
B
Barry White
Replace the whole unit with a rebuilt one theres about 9 diodes in the pack some to do with regulation too and a lot of heavy soldering to the windings. Then theres the voltage regulator a square block filled with resin with 3 or 4 wires coming out to test.
I had a look at the two old rectifier boards in my spares, both presumably in need of replacement. And yep, those diodes are swaged in or some such - not a simple solder-replacement at all. And of course, they all test fine anyway, but...I musta taken them out of service for SOME reason, right?
Going back to the basic-test setup, though, I noticed, while disassembling the old alternators, that the other removable modular board - holding the brushes and regulator - won't get any connection outside the alternator case unless that small QD terminal (that "small wire") is connected - that's where that terminal connects via a short wire, within the alternator's internal connections. That being the case, only the brushes will be connected to the regulator board, if the "charge light" wire is indeed not landed on a 12V source. So is it really true that the small wire isn't needed for the alternator to charge? Or might it really be that it will still charge, but with no upper-limit on the voltage - so better not run it like that other than for testing purposes?
--Dave
Going back to the basic-test setup, though, I noticed, while disassembling the old alternators, that the other removable modular board - holding the brushes and regulator - won't get any connection outside the alternator case unless that small QD terminal (that "small wire") is connected - that's where that terminal connects via a short wire, within the alternator's internal connections. That being the case, only the brushes will be connected to the regulator board, if the "charge light" wire is indeed not landed on a 12V source. So is it really true that the small wire isn't needed for the alternator to charge? Or might it really be that it will still charge, but with no upper-limit on the voltage - so better not run it like that other than for testing purposes?
--Dave
E
electron1
When I fitted a 17ACR Alt to a Ford Escort back in the 70's, the small terminal was indeed for the "Ignition" Light.
Literature at the time suggested that this wire fed the Field windings from the switched ignition supply.
Literature at the time suggested that this wire fed the Field windings from the switched ignition supply.
B
Barry White
I stated earlier that the small spade conector on the alternator was used as an indicator only and had no other function (this is from personal experience) But 3 other people Peg, Ruston, and Electron say it also excites the wiring checking on google gives mixed reviews but most are for fitting a 2w bulb to excite the alternator.
Maybe I am wrong then? Its deffo worth a try you need a 12v 2w bulb conect one side to the small spade conector on the alternator the other to 12v supply the bulb should light up. Then start up and see if it charges.
Deffo worth a try
Maybe I am wrong then? Its deffo worth a try you need a 12v 2w bulb conect one side to the small spade conector on the alternator the other to 12v supply the bulb should light up. Then start up and see if it charges.
Deffo worth a try
I know, you thought I'd ****ed off...no such luck. Settle in. Long bumpy ride awaits...
I *did* think I'd got it sorted. I went back to the 15-year-old alternator, after doing a sort of ghetto-bench-test, since I didn't really trust the shop that said "the diodes are failing" - they are, I think, the only rebuilder in town, so how's that for an incentive to exaggerate or outright lie...especially knowing he quoted me $180 (GBP118!) to rebuild. But, "Ghetto-bench test," you ask? Clamped it to a workbench, applied +12V from small lead-acid battery to one large terminal, earthed the case to -, and clipped a test-lamp between the "small terminal" and +12V.
The lamp glowed right off, as it should have. Then with a cordless drill fitted with appropriate socket to drive the field, and...at maybe 1000RPM, the bulb dimmed, current flowed, and voltage rose. Wondrous to behold.
"So," concluded I, "...it was just the battery that was knackered all along...and the belt?... well, it must have nearly worn itself out while struggling to charge that old 2008-vintage battery..."
Thus I refitted the alt, drove out with the missus, enjoyed the absence of a charge-light, and voltage-reading of about 13V, and thought all was well.
But all was not well... Returning home in the dark, it was hard to miss that charge-LED, blinding me with it's infernal, mocking glow. Checked under the bonnet on the way home, and...the belt had SNAPPED. We headed the rest of the way home regardless, me gambling on a convenient theory of convection-current circulating coolant sufficiently to keep me below, say, 800F, what with the electric fan being on. (Actually, it was a short drive, so I chanced it, and did get away with it, somehow, though I watched my temp-gauge a lot more closely than the road.)
In the light of the next day, with the belt no longer a visual impediment, and a (slightly) more critical eye, I noticed finally that there was more than a slight roughness to patches on the cheap stamped-steel alt pulley surface. In fact, on close inspection, I realized that it had a patch that was more like 24-grit sandpaper than anything - though that, too, was masked by a glaze of rubber from the belt.
So THAT was it. Eu-freaking-reka.
Ebay hooked me up with a new solid-steel turned pulley, galvanized, and I futzed around with shimming the pulley to get it aligned just right with the pump and crankshaft. Ebay also provided a matched pair (one for later) of new drive-belts at a bargain. I installed this combination just this afternoon, tested it in the driveway, and all was bliss - no squealing, good voltage, even with headlights ablaze.
Took the same trip out as last week - a few miles each way, returning in the dark. (Can you feel it? Here it comes...) On starting, I had that charge-light, but that's normal - it has always stayed on until I rev the engine up a bit, then it's out for the rest of the drive. I pulled out into a long line of traffic, and it took about ten minutes to get moving, so the charge-light stayed on, since I hadn't wanted to aggravate other drivers by revving crazily. But when I finally got out of that jam, there it was again - that unbearable, miserable squeal, as I revved my way through an almost-red light.
Once at home, I checked under the hood. The belt wasn't too loose, nor too tight, but the new pulley was noticeably warm compared to the others.
So..."diodes are failing," after all? Pffft...
I *did* think I'd got it sorted. I went back to the 15-year-old alternator, after doing a sort of ghetto-bench-test, since I didn't really trust the shop that said "the diodes are failing" - they are, I think, the only rebuilder in town, so how's that for an incentive to exaggerate or outright lie...especially knowing he quoted me $180 (GBP118!) to rebuild. But, "Ghetto-bench test," you ask? Clamped it to a workbench, applied +12V from small lead-acid battery to one large terminal, earthed the case to -, and clipped a test-lamp between the "small terminal" and +12V.
The lamp glowed right off, as it should have. Then with a cordless drill fitted with appropriate socket to drive the field, and...at maybe 1000RPM, the bulb dimmed, current flowed, and voltage rose. Wondrous to behold.
"So," concluded I, "...it was just the battery that was knackered all along...and the belt?... well, it must have nearly worn itself out while struggling to charge that old 2008-vintage battery..."
Thus I refitted the alt, drove out with the missus, enjoyed the absence of a charge-light, and voltage-reading of about 13V, and thought all was well.
But all was not well... Returning home in the dark, it was hard to miss that charge-LED, blinding me with it's infernal, mocking glow. Checked under the bonnet on the way home, and...the belt had SNAPPED. We headed the rest of the way home regardless, me gambling on a convenient theory of convection-current circulating coolant sufficiently to keep me below, say, 800F, what with the electric fan being on. (Actually, it was a short drive, so I chanced it, and did get away with it, somehow, though I watched my temp-gauge a lot more closely than the road.)
In the light of the next day, with the belt no longer a visual impediment, and a (slightly) more critical eye, I noticed finally that there was more than a slight roughness to patches on the cheap stamped-steel alt pulley surface. In fact, on close inspection, I realized that it had a patch that was more like 24-grit sandpaper than anything - though that, too, was masked by a glaze of rubber from the belt.
So THAT was it. Eu-freaking-reka.
Ebay hooked me up with a new solid-steel turned pulley, galvanized, and I futzed around with shimming the pulley to get it aligned just right with the pump and crankshaft. Ebay also provided a matched pair (one for later) of new drive-belts at a bargain. I installed this combination just this afternoon, tested it in the driveway, and all was bliss - no squealing, good voltage, even with headlights ablaze.
Took the same trip out as last week - a few miles each way, returning in the dark. (Can you feel it? Here it comes...) On starting, I had that charge-light, but that's normal - it has always stayed on until I rev the engine up a bit, then it's out for the rest of the drive. I pulled out into a long line of traffic, and it took about ten minutes to get moving, so the charge-light stayed on, since I hadn't wanted to aggravate other drivers by revving crazily. But when I finally got out of that jam, there it was again - that unbearable, miserable squeal, as I revved my way through an almost-red light.
Once at home, I checked under the hood. The belt wasn't too loose, nor too tight, but the new pulley was noticeably warm compared to the others.
So..."diodes are failing," after all? Pffft...
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