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Post by dave1800 on May 17, 2020 8:41:36 GMT
Hi Nick, (edit - have crossed with your latest post!)
Sorry to jump in, but I know you are quite busy and I have a bit (lot!)of time to kill so these are my thoughts for Paddy.
As the alternator field coil appears to be in working order may I suggest the following checks.
a) Increase the idle to around 1300 rpm, if you don't have a tacho then adjust it until it almost double in speed. In theory this shouldn't be necessary but it will test for a weak alternator output as well as no output.
b) disconnect the alternator wires and measure the output voltage from the larger alternator connector to ground and the jump wire (with the bulb) connected to battery positive.
c) take the meter reading on AC from the alternator to ground. It shouldn't be more than 0.2V, preferably zero. If the reading is higher this indicates one or more diodes inside the alternator have gone short circuit or are failing.
d) repeat with the meter switched to DC range. The reading should be around 15-20V at these higher RPM. If not use a jump wire without the bulb and momentarily touch the battery positive. I don't think this is a problem now as it appears the field coil is in order. You could always add a 5A fuse to the jump wire if you feel uncertain.
e) If you do get around 15 volts or more then adjust the idle back to normal. If the voltage falls below around 13V this indicates a fault in the alternator. If that is the case then it would be worth checking the carbon brushes and the diode pack. A diode that has failed open circuit will reduce the output as will worn out brushes. Not sure if the diode pack and brushes are available but if so they will be considerably cheaper than the very high figure I saw recently following a link from the Oz crab website.
f) Don't worry about the dash charging warning light at this stage the main thing now is to check whether the problem is with the alternator. If it checks out OK then the voltage regulator, wiring and warning light are next in line!
David
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Post by 1800heap on May 17, 2020 9:17:58 GMT
Hi David
I wasn't that convinced by Paddys post that his bulb had a decent glow. Hence my post. If the brushes are nasty you might only get a slight glow and we are then assumming that the field coils are working normally when in fact he might just need a new set of brushes. Although I have not looked I suspect these units are not that easy to get! For diode issues I would not consider trying to repair the unit myself, brushes I would so I don't want him to miss that oportunity. I am starting to think we are bogging Paddy down a bit with too many things to check at once. Given his latest results the only worry in calling it after a resistance check of the field coils is the altenator output to solenoid cable. An easy check for this would be to load it with the bulb incase it only has a few good strands thats making it pass the continuity check.
Nick
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Post by dave1800 on May 17, 2020 11:33:15 GMT
Good thinking, Nick. That makes better sense, a much quicker check for Paddy to load the wiring as you described.
David
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Post by paddymk2 on May 17, 2020 12:39:44 GMT
Hi
Just a little bit of background to explain the situation better.
The auto transmission was slipping and to save costs I agreed to take out the engine. (There's a first time for everything - call it learning)
It took a longtime to get all the parts including gaskets and a cracked servo and then the Lockdown.
I put the engine back reconnected it and put in fluids.
Unfortunately most of the transmission fluid leaked out again AND i can't move the gear selector.
So I need to bring the car back to the transmission shop.
I'm in neutral/park but I'm not comfortable running up the engine for longer than a few minute or so.
I'll bring it to the transmission guy on weds - and I'm hoping to drive it the 20 minute home!
That said, it should be ok to check for lead continuity by connecting one end of the lead with the bulb to the B-terminal on the alternator and the other end to the lead just disconnected from the B terminal (?)
Paddy
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Post by 1800heap on May 17, 2020 23:03:07 GMT
Hi Just a little bit of background to explain the situation better. The auto transmission was slipping and to save costs I agreed to take out the engine. (There's a first time for everything - call it learning) It took a longtime to get all the parts including gaskets and a cracked servo and then the Lockdown. I put the engine back reconnected it and put in fluids. Unfortunately most of the transmission fluid leaked out again AND i can't move the gear selector. So I need to bring the car back to the transmission shop. I'm in neutral/park but I'm not comfortable running up the engine for longer than a few minute or so. I'll bring it to the transmission guy on weds - and I'm hoping to drive it the 20 minute home! That said, it should be ok to check for lead continuity by connecting one end of the lead with the bulb to the B-terminal on the alternator and the other end to the lead just disconnected from the B terminal (?)
Paddy
Hi Paddy Sorry to hear about your gearbox issues, thats no fun. Charging problems as well! Always the way isn't it. At the moment I am leaning towards a faulty alternator. If the alternators were easy to get or cheap I would just get one if it were me. I don't think this is the case though. Have you had a look to see what there is in the way of replacements? At the moment we can't really call it for you so you may get a new one and still have an issue at this stage. There are a couple of questions you need to answer for us to get a better idea of what is going on and to save going in circles. First you didn't say if your bulb was as bright as my one in the picture? Second you didn't say if you tested for AC volts as well as DC when you did the field coil test? Next although you have done several continuity tests these can be misleading for certain issues as multimeters are not very accurate at measuring low resistances. For example a battery cable may still pass a continuity test if all but one of the strands in the wire is broken/corroded but no way will it turn the car over, it will just get really hot! The good news is there are a couple of tests you can do without starting the car that may help if you are woried about that. These are what I was talking about in the posts to David. 1 Set your multimeter to DC volts and connect the red multimeter lead to the positive at the battery. Engine off battery connected. 2 Connect the black multimeter lead to the alternator output bolt/lug ( B - terminal ) All connectons to the alternator should be in place as they would be for normal running. 3 With your test bulb connect one side of it to a good earth on the body of the alternator. 4 Connect the other side of the bulb to the alternator output bolt/lug (B - terminal) the same place as the multimeter black lead. This should make the lamp light brightly the same as it would direct accross the battery. Take care not to short the B -Term to the body of the alternator! 5 Make a note of the voltage reading on the multimeter if there is one. Second test Disconnect the battery positive and then the aux/field coil plug from the alternator. Measure the resistance from the body of the alternator on a good clean earth point to the field coil lug on the alternator. Note the resistance. Results we need from you. A. Voltage from 5 B. Did the bult light as if connected to the battery (bright). C. Resistance of field coil. Nick |
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Post by paddymk2 on May 18, 2020 13:08:11 GMT
Hi Nick Yes I missed the AC measurement and I didn't hold the wire there long during yesterday's test - I think it was more glowing than bright This evening I measure the voltage as per test 5 - It fluctuated a bit but was around 0.45V
- The bulb was glowing very bright like in your bright pic
- The resistance at fld was 14.6ohm (15.5ohm - 0.9ohm) for the ohmmeter.
Thanks for the help
Paddy
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Post by 1800heap on May 18, 2020 22:30:39 GMT
Hi Nick Yes I missed the AC measurement and I didn't hold the wire there long during yesterday's test - I think it was more glowing than bright This evening I measure the voltage as per test 5 - It fluctuated a bit but was around 0.45V
- The bulb was glowing very bright like in your bright pic
- The resistance at fld was 14.6ohm (15.5ohm - 0.9ohm) for the ohmmeter.
Thanks for the help
Paddy
Hi Paddy With those numbers you have two issue mate. Your measurement of voltage is the drop accross the cable section from alternator to battery positive. This number although small is excessive for a think cable like that. As I said before, a test meter will measure this as continuity but a rough calculation tells me you have .25ohms so your .45volts is very high for a think cable like that, with only 1.7 amps running through it! I got .021volts and .013 ohms when I tested my cars cable. This is way better than yours and it might still be a tad high!. Now an important thing here is you got the number right! If your measurement was .045volts not .45volts that is 10 times better, although you still got double what mine was! If your voltage is correct at .45 you need to at least remake both the ends of the alternator to solenoid cable with new connectors then retest it. Next problem is your field coil resistance. This is also high. You should get around 8 ohms. Again if 14.6 ohms is correct this is high suggesting a possible problem with the brushes in the alternator amongst other things. I am a bit suspect of your test meter though as the short test on your leads is very unstable! Might be worth cleaning and tightening the connectors on that so you get a stable pretest number! Nick |
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Post by paddymk2 on May 19, 2020 3:24:46 GMT
Hi NIck I 'll borrow or get hold of a better multimeter - the short test was as good as I've seen it on that device. Paddy |
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Post by dave1800 on May 19, 2020 7:16:25 GMT
You don't need anything too special. I see Jaycar have a basic meter here and guess they probably have a store near you. (Note it's NOT suitable for working with household mains AC voltages which is true of most cheap meters). We used to have similar local stores in the UK called Maplin, handy for the odd thing but not necessarily the cheapest. I've bought a few things from Jaycar over the years and they've been OK. (I don't have any financial interests in Jaycar!- just using this as an example of what is around you may find useful). There's nothing worse than a bad meter it can waste hours of your time and potentially cost you money - the voice of bitter experience! David Hi NIck I 'll borrow or get hold of a better multimeter - the short test was as good as I've seen it on that device. Paddy |
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Post by paddymk2 on May 19, 2020 13:10:20 GMT
Hi that was very interesting.
i got hold of the $43 meter (smaller and less buttons than the $8.50 one)
i screw clamped the test wire to the b-terminal and scratched the contact point on the alternator casing.
Result: bright light and a flicker between 0,01 and 0.00V
But on the second test the resistance was as low as 7.9 ohms but it was easy to wiggle the spade connector ever so slightly and get it to jump to 37 or 55 ohms.
im wondering if thats the dodgey link.
the batterys on charge tonight
fingers crossed for mr gearbox tomorrow.
cheers paddy
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Post by 1800heap on May 20, 2020 6:56:40 GMT
Hi that was very interesting. i got hold of the $43 meter (smaller and less buttons than the $8.50 one) i screw clamped the test wire to the b-terminal and scratched the contact point on the alternator casing. Result: bright light and a flicker between 0,01 and 0.00V But on the second test the resistance was as low as 7.9 ohms but it was easy to wiggle the spade connector ever so slightly and get it to jump to 37 or 55 ohms. im wondering if thats the dodgey link. the batterys on charge tonight fingers crossed for mr gearbox tomorrow. cheers paddy Hi Paddy That would be it I would think paddy. How you fix it will be interesting! Good luck with the gear box. Nick |
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Post by andrewa on May 20, 2020 18:38:00 GMT
Been watching this thread develop with interest - it's like a whodunnit!
Good luck with the 'box.
Cheers
Andrew
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Post by paddymk2 on May 21, 2020 3:02:05 GMT
So my thoughts were: (A) Get the car back!, wiggle the offending connection and hope it comes good... (B) Get a replacement alternator, then dismantle and tinker with the Email unit. The Email alternator is made under license (not Lucas or Bosch) and comes from a time when Australian content rules were highest. It would be nice to keep it. On the other hand I saw this attachment A2.pdf (47.59 KB) at the other site and thought that would be cost effective swap. There are plenty of Mitusbishi Magnas around (they were the 3rd Car in Australia for a couple of decades.) Paddy |
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Post by andrewa on May 21, 2020 22:14:27 GMT
Based on his write up the Magna option has got to be worth a go I would have thought....
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Post by 1800heap on May 22, 2020 1:55:03 GMT
Based on his write up the Magna option has got to be worth a go I would have thought.... Sounds like the go Andrew doesn't it. Unless you have a particular need to stay OEM Paddy! Some like to keep them original. I expect it is a whole lot cheaper than getting a Lucus unit too! Unless your old unit is an easy fix of course which I can't tell you Paddy. I don't want to pull apart my working unit to look. You will have to change the wiring a bit to get rid of the external reg though I would think. Nick |
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