naru Posted January 11, 2018 Share Posted January 11, 2018 At this point,I would remove the small plug and jumper 12 volts to both terminals. Put a jumper cable berween the alternator case and battery negative too. If the alternator still does not charge,it is NFG. (give it some rpms-idle speed is insufficent) Quote Link to comment Share on other sites More sharing options...
QuinnG Posted January 12, 2018 Author Share Posted January 12, 2018 Anybody have a cluster out of their 82 gl and can take some ohm readings for me? Quote Link to comment Share on other sites More sharing options...
QuinnG Posted January 12, 2018 Author Share Posted January 12, 2018 If I put 12v to both spades in the back of the Alt and it starts charging but it sounds like it’s working super hard. The battery is fully charged Quote Link to comment Share on other sites More sharing options...
naru Posted January 12, 2018 Share Posted January 12, 2018 Anybody have a cluster out of their 82 gl and can take some ohm readings for me Unlikely. Waste of time anyhow. The white/red wire goes to battery positive thru the fuse,charge bulb,ignition switch and fusible link. The only resistance between the plug and battery positive should be the bulb Quote Link to comment Share on other sites More sharing options...
naru Posted January 12, 2018 Share Posted January 12, 2018 sounds like it’s working super hard. The battery is fully charged What do you mean? Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 12, 2018 Share Posted January 12, 2018 (edited) Edited to remove possibly incorrect info.I never had a 1982 or close model, so I can't get more specific about this situation. Edited January 12, 2018 by DaveT Quote Link to comment Share on other sites More sharing options...
naru Posted January 12, 2018 Share Posted January 12, 2018 Without schematics, I cannot be sure, but connecting both of the small terminals directly to 12v is not going to be good. One is meant to, and the other is likely not. I never had an 82 or close model, so I can't get more specific. BS-You should resist commenting when you do not know what you are talking about. An 82 uses the same voltage regulator as your non XT EA82s. This is not rocket science. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 12, 2018 Share Posted January 12, 2018 WTF? No need to be snotty. The details went past my experience. General stuff is general. I have no specific info regarding 1982 models, so I am done with this thread. Quote Link to comment Share on other sites More sharing options...
Billyt Posted January 13, 2018 Share Posted January 13, 2018 Dead fusible link? I can't remember if the charge wire goes through the fusible link. The reference wire certainly would. I'd be checking these to ensure they're all in good health. Cheers Bennie Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 13, 2018 Share Posted January 13, 2018 If I put 12v to both spades in the back of the Alt and it starts charging but it sounds like it’s working super hard. The battery is fully charged don't do this. The L terminal (white/red wire) does get 12v but it need to come through an induced load, i.e. the "charge" lamp. That terminal is a ground connection when alt is not spinning. It becomes a source of voltage when the alt starts operating. This drives the volts high .This is the action that turns off the light. The alt basically finds a balance on both sides of the bulb that keeps the light off. keeps the volts equal from both ends. without a load in line, you have a dead short when the alt is not spinning. Could start a fire without a load inline there, you are basically creating a dead short. Quote Link to comment Share on other sites More sharing options...
naru Posted January 13, 2018 Share Posted January 13, 2018 (edited) Gloyale, on 13 Jan 2018 - 10:21, said: don't do this. The L terminal (white/red wire) does get 12v but it need to come through an induced load, i.e. the "charge" lamp. That terminal is a ground connection when alt is not spinning. It becomes a source of voltage when the alt starts operating. This drives the volts high .This is the action that turns off the light. The alt basically finds a balance on both sides of the bulb that keeps the light off. keeps the volts equal from both ends. without a load in line, you have a dead short when the alt is not spinning. Could start a fire without a load inline there, you are basically creating a dead short. Indeed,I would only do this as a short term test to prove the fault lies w/the wiring and not the alternator. But.... When the alternator is not spinning and the key is on: The white red/wire does not get 12 volts. I measure about 3.5 w/the bulb in the circuit. There is no dead short. If there was a dead short,voltage would be 0 at the plug. The field coil is in the circuit,4-5 ohms.It sees 12+ volts all the time Only danger I see is a higher than normal current thru the transistor that controls field current until the alternator spins. A switch in the white/red jumper would be a good idea. One should only have to turn it on for a couple of seconds to self excite the alternator. Edited January 13, 2018 by naru Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 15, 2018 Share Posted January 15, 2018 Indeed,I would only do this as a short term test to prove the fault lies w/the wiring and not the alternator. But.... When the alternator is not spinning and the key is on: The white red/wire does not get 12 volts. I measure about 3.5 w/the bulb in the circuit. There is no dead short. If there was a dead short,voltage would be 0 at the plug. The field coil is in the circuit,4-5 ohms.It sees 12+ volts all the time Only danger I see is a higher than normal current thru the transistor that controls field current until the alternator spins. A switch in the white/red jumper would be a good idea. One should only have to turn it on for a couple of seconds to self excite the alternator. 12v to one side of bulb, other side to L terminal. When ALT is not spinning, that terminal is ground. That is why the light comes on! THERE MUST BE A LOAD ON THE L TERMINAL. You will fry the alt if you apply 12v directly without going through a load. Quote Link to comment Share on other sites More sharing options...
naru Posted January 15, 2018 Share Posted January 15, 2018 12v to one side of bulb, other side to L terminal. When ALT is not spinning, that terminal is ground. That is why the light comes on! THERE MUST BE A LOAD ON THE L TERMINAL. You will fry the alt if you apply 12v directly without going through a load. The L terminal is NOT ground. It is 3.5 volts above ground. THERE IS A LOAD ON THE L TERMINAL-the field coil The whole purpose of the L wire is to supply intial field cutrrent.. What part of this don`t you understand? And while we are correcting mistakes,the charge lamp is neither an induced load nor an inductive one. Quote Link to comment Share on other sites More sharing options...
naru Posted January 15, 2018 Share Posted January 15, 2018 I think I’m getting closer. The two pin plug on the back of the Alt has 12v at the white and 1.7 at the white w/red. Shouldn’t they both be 12v when the car is running??? Both should be 12V running. The white/red will be about 3.5V not running.(key on) Apparently 1.7V is not enough to get the alternator charging. You have a bad connection somewhere along the path of the white/red wire back to battery positive that adds resistance and drops the voltage too low. Find it by taking voltage measurements along the way.(key on) Should be 3.5V all the way back thru the fuse to one side of the charge lamp. Other side of the lamp should be battery voltage all the way back thru the ignition switch and fusible link. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 15, 2018 Share Posted January 15, 2018 The L terminal is NOT ground. It is 3.5 volts above ground. I'm not doing this again with you. Go ahead and advise this guy on how to fry his alt by bypassing the load. I am sure Subaru engineered the whole system wrong, and you should ignore their design and do it your way. I'm out. Quote Link to comment Share on other sites More sharing options...
naru Posted January 15, 2018 Share Posted January 15, 2018 I'm not doing this again with you. Go ahead and advise this guy on how to fry his alt by bypassing the load. I am sure Subaru engineered the whole system wrong, and you should ignore their design and do it your way. I'm out. Subaru engineered it just fine. It is not thier fault you don`t understand it. Yes,I recall that you do not understand Ohm`s law. You should not give advice until you do. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 15, 2018 Share Posted January 15, 2018 Proper test diagrahm. Notice the Lamp and additionally a 100 ohm resistor on the "L" wire IMG_2813 by Dans Subaru, on Flickr Quote Link to comment Share on other sites More sharing options...
Dee2 Posted January 15, 2018 Share Posted January 15, 2018 (edited) Maybe this will help. How to test an alternator. Diagnosing Alternator problems If the alternator checks out and the battery is still going dead, then the likely culprit is a parasitic drain and there are more videos for tracking down that problem. Edited January 15, 2018 by Dee2 Quote Link to comment Share on other sites More sharing options...
naru Posted January 15, 2018 Share Posted January 15, 2018 Gloyale, on 15 Jan 2018 - 12:06, said: Proper test diagrahm. Notice the Lamp and additionally a 100 ohm resistor on the "L" wire IMG_2813 by Dans Subaru, on Flickr Notice that there is a parallel wire running DIRECTLY from L to battery positive. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 16, 2018 Share Posted January 16, 2018 Notice that there is a parallel wire running DIRECTLY from L to battery positive. slightly deceptive labeling of the diagram. That's the B terminal and if it isn't, then tell me where the B terminal would be? not the line with the switch on it, that is the "S" the one above "E" is the grounded case of the ALT. Quote Link to comment Share on other sites More sharing options...
naru Posted January 16, 2018 Share Posted January 16, 2018 That is a screwy diagram. One of the terminals is missing and having 2 wires on L makes no sense. I agree that it is highly preferable to power L thru the correct voltage dropping lamp(no resistor on ea81s) and known good wiring,but I can`t agree with your doomsday predictions for a quick test w/o the lamp. The OP has already determined his original 1.7 volts at L was insufficient and there is a wiring problem w/this technique. Quote Link to comment Share on other sites More sharing options...
QuinnG Posted January 16, 2018 Author Share Posted January 16, 2018 Ok so I checked the white wire w/red from the alternator to the black plug under the dash to the fuse block, not broken and zero resistance. With the fuse out it’s 12 volts running. Put the fuse in and it drops to 1.7. I follow it from the other side of the fuse (tan w/blue) up to the plug on the cluster. The cluster seems to be stepping it way down. All my bulbs work. Is it stepped down at the Volt meter??? Quote Link to comment Share on other sites More sharing options...
naru Posted January 16, 2018 Share Posted January 16, 2018 The charge lamp is the only thing that is supposed to affect the voltage on the white/red. One side of the bulb should be battery voltage. The other side should be around 3.5 volts or so. What voltages do you have? There is no voodoo majic inside the cluster affecting the voltage. Just the bulb. Quote Link to comment Share on other sites More sharing options...
naru Posted January 16, 2018 Share Posted January 16, 2018 What voltage do you have going into the cluster at the plug? Measure at pin #5 of the LH plug when looking from the rear(count clockwise from the gap) Upon reflection,there are a couple of diodes in the cluster that could affect things if they were faulty as well. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 16, 2018 Share Posted January 16, 2018 (edited) better diagram For XT but electrically excactly the same as any internal reg. EA alternator. IMG_2814 by Dans Subaru, on Flickr IMG_2814 by Dans Subaru, on Flickr Edited January 16, 2018 by Gloyale Quote Link to comment Share on other sites More sharing options...
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