ihiryu Posted November 11, 2012 Share Posted November 11, 2012 I just completed my RB20 swap on my 76. I set my multimeter to to amps, and put it in line of the positive battery cable to terminal, and got 1.34 on the meter. I began with removing the fuses I added, and the maxi-fuses. When I removed the fuse for the alternator the drain dropped down just a little, (IIRC it went down to 1.2 or so), but still way over the limit. At that point I disconnected all the interior fuses, and even the ECU with no luck. Any other ideas guys? Quote Link to comment Share on other sites More sharing options...
dexter72 Posted November 11, 2012 Share Posted November 11, 2012 Now try disconnecting the radio, speaker Amp,Upgraded headlights, and so on. and any other things that have been added to the car. For the alternator i would remove the power wire not just the fuse. I also think the multi meter setting should be on Ma and around 400ma is ok for a system draw. correct me if i am wrong. Quote Link to comment Share on other sites More sharing options...
ihiryu Posted November 11, 2012 Author Share Posted November 11, 2012 All that stuff is fused. The only thing it's funny because I was thinking about disconnected the battery power wire from the alternator. That and the starter. Quote Link to comment Share on other sites More sharing options...
Domzs Posted November 11, 2012 Share Posted November 11, 2012 Can you post pic of your add-ons ( fuse box ) ? Have you tried removing fusible links , if you still have them ? Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 11, 2012 Share Posted November 11, 2012 Alternators can cause a short, either through a failed component or just dirt and carbon creating a conductive path to ground. Disconnecting the wires is a simple test. Disconnect all of them, S, L, and battery. If it's the problem check the condenser/capacitor connected to the B+ wire before replacing the alternator. The same thoughts apply to the starter, lots of exposed positive connections and possible short paths. Quote Link to comment Share on other sites More sharing options...
ihiryu Posted November 11, 2012 Author Share Posted November 11, 2012 Can you post pic of your add-ons ( fuse box ) ? Have you tried removing fusible links , if you still have them ? The add-ons are just a regular aftermarket fuse box that is connected to the positive battery terminal. And yes, I have tried to remove them. Alternators can cause a short, either through a failed component or just dirt and carbon creating a conductive path to ground. Disconnecting the wires is a simple test. Disconnect all of them, S, L, and battery. If it's the problem check the condenser/capacitor connected to the B+ wire before replacing the alternator. The same thoughts apply to the starter, lots of exposed positive connections and possible short paths. The only thing that is a bit hard is the battery positive on the alternator, a tight place to get to it. Where is the condenser at? For some reason I don't recall seeing it. I spliced the factory wiring to the RB alternator plug. And ditched the external regulator. Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 11, 2012 Share Posted November 11, 2012 (edited) I spliced the factory wiring to the RB alternator plug. And ditched the external regulator. If you followed the atlanticz write-up for the alternator swap then the brake check warning lamp relay under the passenger seat is probably on all the time. You can cut the yellow wire to the relay and splice it in to your fuel pump circuit to power the relay, if you want the light to work, otherwise you can just cut the wire and tape the ends. I have a 76 and I had the same problem after converting to the newer regulator setup. If I recall, the yellow wire is tapped in to the same wire that S uses so it's a direct connection to the battery. Check the wiring diagram first and check the wires for power to be sure, before you take a chance on my memory. I think it's described in Body Electrical in the FSM. Edited November 11, 2012 by NewZed Quote Link to comment Share on other sites More sharing options...
Domzs Posted November 12, 2012 Share Posted November 12, 2012 Does the drain go away if you remove power from your add-on fuse box ? I like to use low amp probe when i check for battery draw . Max 50mA is acceptable . Some cars allow up tp 75 mA . Quote Link to comment Share on other sites More sharing options...
ihiryu Posted November 12, 2012 Author Share Posted November 12, 2012 If you followed the atlanticz write-up for the alternator swap then the brake check warning lamp relay under the passenger seat is probably on all the time. You can cut the yellow wire to the relay and splice it in to your fuel pump circuit to power the relay, if you want the light to work, otherwise you can just cut the wire and tape the ends. I have a 76 and I had the same problem after converting to the newer regulator setup. If I recall, the yellow wire is tapped in to the same wire that S uses so it's a direct connection to the battery. Check the wiring diagram first and check the wires for power to be sure, before you take a chance on my memory. I think it's described in Body Electrical in the FSM. Got home removed my seat, check both plugs for power, and none of them had power with the key off. Disconnected the positive cable and put the multimeter between it set on amps, disconnected both plugs from their respective relays and nothing. Removed my maxi fuse for the alternator and the drain is slowly dropping. I'm going to let it sit and wait for it to settle. Unfortunately it wasn't the seat relay even though I followed the alantic z car write up as well. Does the drain go away if you remove power from your add-on fuse box ? I like to use low amp probe when i check for battery draw . Max 50mA is acceptable . Some cars allow up tp 75 mA . No it doesn't. My draw for some reason is at 5 amps, instead of the 1.34 or whatever it was at before. Disconnected the fuse for the alternator is causing it to slowly drop though. Quote Link to comment Share on other sites More sharing options...
ihiryu Posted November 12, 2012 Author Share Posted November 12, 2012 So I think I did my test wrong or something previously. On the RB swap there is two wires that need 12+ all the time; ECU memory and one other one. I tied both of them together and fused it to my add-on fuse box to a 30 amp fuse. I wired up my CEL light via the floor lamp by cutting both wires, adding on to the battery to a 5 amp fuse, and the other to the ECU (ecu grounds that wire). I removed the ECU fuse, and the CEL fuse, along with the Alternator Maxi fuse, and my power draw disappeared all together. I find that very strange since the ECU must have those wires to keep the ECU memory, so I'm starting to think that my ECU is staying on. I had to remove one of two of the relays since one of them would keep the ECU on (which I've read elsewhere). I realized that after I wired up my CEL (since the the CEL stayed lit even though the key was off). If I reinstall any of the three fuses the draw comes back. With just the CEL fuse installed the draw goes up to 3.xx amps. The ECU fuse alone shoots up to 4.xx amps, and the alternator maxi fuse alone it goes up to a whopping 5.27 amps of draw. At this point I'm really confused on what is going on. I followed the swap write up, and took a look at the wiring for the s13/s14 and they virtually do the same thing. Two wires to +12v, one to ignition on, one to start. Plus fuel pump relay. I've checked those wires over and over again to get it right. At this point I don't know what's going on with the ECU side of things. I guess for now I'll just keep those three fuses disconnected overnight. Quote Link to comment Share on other sites More sharing options...
Domzs Posted November 13, 2012 Share Posted November 13, 2012 (edited) Don't know much about the RB swap . I would wire the CEL hot when key on . Disconnect fuel pump relay to see the draw goes away or down . Good luck . Edited November 13, 2012 by Domzs Quote Link to comment Share on other sites More sharing options...
ihiryu Posted November 13, 2012 Author Share Posted November 13, 2012 Okay guys, I hate to say this, but my old man shows me up again. When I was talking to my old man (he came over last night to steal some of my beer) about my predicament he asks me if I was using the multimeter right. I never swapped the red pin from the Ohm/Continuity port on my Fluke. So late last night I moved the red over to the 10a slot and test again. ECU and CEL have no draw. ONLY the alternator has a draw. I also removed the starter from my battery terminal to make sure it wasn't the starter. When I got home, I removed the alternator fuse, let the car sit, and this morning plugged it back in, and it started right up. So it's confirmed that somewhere in the wiring is my draw. I'm looking through the FSM, but it doesn't show the entire circuit of the alternator. Can someone correct me if I'm wrong, but to my understanding the alternator is actually daisy chained. Alternator->starter->maxi fuse->battery. Is that right? Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 13, 2012 Share Posted November 13, 2012 Everything has (had, in your case) a fusible link or fuse between it and ground except the main cable from the battery to the starter, and a few odd wires like the yellow Sense wire or the Lamp wire (which pass through the VR in the stock 1976 configuration). The power branches off to various places (headlights, accessory circuit, ignition) through the fusible links, it's not in serial to the battery. After starting, the battery is just one more load for the alternator to handle. Here is an easy to use wiring diagram put together by a guy over on Classiczcar. http://www.classiczcars.com/forums/thread36494.html Quote Link to comment Share on other sites More sharing options...
ihiryu Posted November 13, 2012 Author Share Posted November 13, 2012 NewZed Thanks so much! You wouldn't believe how much that helps me! Quote Link to comment Share on other sites More sharing options...
darom Posted November 22, 2012 Share Posted November 22, 2012 After swapping fusible links to the blade fuses per Blue's web site on my 76, in addition to the brake light relay, I also had the EGR solenoid's circuit being energized with the ignition key off. Maybe on yours, it is worth checking out as well? I had to re-wire it to allow the igntion key to deliver 12V. Quote Link to comment Share on other sites More sharing options...
ihiryu Posted November 26, 2012 Author Share Posted November 26, 2012 Could you link me to Blue's website? Quote Link to comment Share on other sites More sharing options...
ihiryu Posted December 5, 2012 Author Share Posted December 5, 2012 So here's an update, I figured out what's wrong. It took me a little bit of time of going over everything I did, and I feel a bit sheepish about it now. I followed the Atlantic Z car's guide which states to hook up two and three together, HOWEVER On Z car creation's page, it shows to hook up THREE and SIX together. I hooked up three and six together, now my charge light is working, and it seems like my drain is gone (verified through a craftsman multimeter not my trusty fluke though). Seems like this is specific to the 76 though. Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 5, 2012 Share Posted December 5, 2012 (edited) What is your brake check light doing? Probably doesn't work anymore (I think it doesn't come on now since that's where the drain was attached), but may not be a big deal to you since you can tell problems through brake performance anyway. That's the difference between the two writeups. Battery drain or non-working brake check light. Edited December 5, 2012 by NewZed Quote Link to comment Share on other sites More sharing options...
ihiryu Posted December 5, 2012 Author Share Posted December 5, 2012 Well I'll gladly take a missing brake light instead of a battery drain Quote Link to comment Share on other sites More sharing options...
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