LoneStarS30Z Posted May 20, 2011 Share Posted May 20, 2011 (edited) So here's the story. '72 240Z with L28ET. The car has been doing great, I came home from overseas and have added a lot of parts. The only electrical parts I changed were the headunit/speakers,replaced my narrowband with a wideband, installed the upgraded side marker harness, and a push button start offered by Dave on this site. So the wiring for the headunit was already there, I basically unplugged and plugged in. So first off, the car did well and everything was looking good. Then one day I went out to start the car and got the dreaded "click!" sound. I replaced the battery with an Optima unit along with new battery cables, stick got the click. Narrowed it down to the starter solenoid, replaced it, and everything worked fine again. Then yesterday it worked great all day, even drove around for a few hours as I was to take it to get inspected the next day, which is today. So, earlier this morning, the car starts up fine, runs fine, etc. Arrive at the inspection station, the tech starts the car, drives through the parking lot to make sure the brakes work, then pulls into the bay and does his inspection. He calls me to turn on the lights, and I do so. He then instructs me to use the turn signals and I flip the stalk....no turn signals. WTF?! My turn signals have been solid for a long time now and work every time. In confusion, I admit defeat and tell him I'll come back. The tech hops in the start the car and now another WTF! It won't start! So we jump it and it works, and I drove off in more confusion. Along the way I'm flipping the turn signals off and on and they're working just fine. I drove around a bit thinking the alternator will charge the battery up. I get home, turn the car off, then try to start it. It cranks and cranks and slowly starts losing power until I get the "clicklickclickclickclick". So I suspect the alternator is dead and replace it with the upgraded alternator MSA offers. I should mention I could not find my voltage regulator ANYWHERE, so I'm assuming the PO took it out during the L28ET install. So I get to working on replacing the alternator, finally do so, and use another car to jump mine. Car works good for a few minutes after I take the jumper cables off. Then I notice my headunit won't turn on, then I notice my digital gauge fluctuating, then slowly but surely the car dies. WTF?! I installed the alternator according to the instructions, and even the picture matches my set up as far as the black wire connected to "E", and the red/white cable on "BAT". I jumped it again, let it sit again, and it died even faster that the first time I tried. Looks like I'm in for some fun, can any of you knowledgeable gentlemen tell me where to start while I do some researching? Edited May 20, 2011 by LoneStarS30Z Quote Link to comment Share on other sites More sharing options...
Leon Posted May 20, 2011 Share Posted May 20, 2011 Have you measured the voltage at the battery when the car is running? When revved to about 3k rpm? It should be around 14.5 volts if your system is charging. My 260Z had that problem. I traced wires, cleaned some connections and all was good. These cars often have issues caused by poor electrical connections. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted May 20, 2011 Author Share Posted May 20, 2011 I will have to try that, have to acquire a multimeter in the near future. For now I'm just going to run through everything and make sure I have no exposed wires. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 20, 2011 Share Posted May 20, 2011 If your car wiring has been modified to use an internally regulated alternator (which might be why you can't find the regulator, because the PO did take it out) then the "upgraded" alternator that MSA offers my not be the right replacement, if you bought the upgraded alt for a '72 240Z. You might have created a short when you re-installed a non-regulated alternator, draining your battery. Either way, you should confirm that you have the right mix of parts. The wiring changes will be back where the voltage regulator should/would be, not at the alternator. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted May 20, 2011 Author Share Posted May 20, 2011 If your car wiring has been modified to use an internally regulated alternator (which might be why you can't find the regulator, because the PO did take it out) then the "upgraded" alternator that MSA offers my not be the right replacement, if you bought the upgraded alt for a '72 240Z. You might have created a short when you re-installed a non-regulated alternator, draining your battery. Either way, you should confirm that you have the right mix of parts. The wiring changes will be back where the voltage regulator should/would be, not at the alternator. Well I was under the assumption that since the the regulator is gone, the alternator I pulled was internally regulated since it's run fine all this time. The MSA alternator is also internally regulated: 60-Amp Alternator Upgrade Kit, 70-73 240Z And what's more, the kit comes with that plug that would get plugged into if I did still indeed have the regulator left. I talk to Dave who made this plug after my original confusion on where the regulator was at and he said: "The Plug has a jumper and a diode that make the right connections to bypass the voltage regulator make the connections that the VR used to make. The diode keeps the alternator from powering the ignition. That causes the engine to not shut off. so it's all needed." So the regulator is out of the question, however like you've mentioned, the wiring could be suspect. I need to find a ::gulp::, schematic and start chasing wires. The more I think about it though, the more I think it's extremely odd the car starting acting up out of the blue once the tech drove it. I'm really hoping he accidently kicked something under the dash. About to go take flash light to it real quick. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted May 20, 2011 Author Share Posted May 20, 2011 (edited) Ok fellas, I've picked a multimeter and got multimetering, and for sure, there's a drainage somewhere in the system. I also took the original alternator to be tested, and it passed twice. Here's my readings: Battery only, no ACC/Power applied - 10.86V Battery, jumper cables applied - 12.89V Alternator, jumpers cables installed - 12.52V I took off the jumper cables off and kept the multimeter on the battery and watched the voltage slowly drop. I moved the multimeter over to the alternator and watched it drop also. With the car off, no power applied, I then checked the battery again, it read 11.47V, which means the alternator is indeed doing it's job right? it charged the battery nearly 1V. I then turned my ACC on and measured the battery, and sure enough the voltage was slowly dropping. So if my assumption is correct, the battery and alternator are working correctly, and somehow somewhere, somethings grounding out? Edited May 20, 2011 by LoneStarS30Z Quote Link to comment Share on other sites More sharing options...
dexter72 Posted May 20, 2011 Share Posted May 20, 2011 With a working alternator your battery voltage should be from 13.0 volts up to 14.9 volts. From your readings I will say the alternator is not charging the battery. Your battery voltage should be 12 volts. Get the battery charged up first. A lot of shops have a newer type of charger that will charge the jell type AGM, Optima Batteries. I would also check your system for a draw. I would disconnect that new head unit you installed. Seems like the problems started with that install. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted May 20, 2011 Author Share Posted May 20, 2011 (edited) With a working alternator your battery voltage should be from 13.0 volts up to 14.9 volts. From your readings I will say the alternator is not charging the battery. Your battery voltage should be 12 volts. Get the battery charged up first. A lot of shops have a newer type of charger that will charge the jell type AGM, Optima Batteries. I would also check your system for a draw. I would disconnect that new head unit you installed. Seems like the problems started with that install. I had the same idea as you just a few minutes ago about disconnecting things. The battery read 13.30V this time with the jumper cables. Before that though, I had the multimeter propped up still reading the battery while I turned ACC on and started disconnecting things. I disconnect power and ground to the head unit and wideband gauge. When I went from having no power applied, to power applied, the voltage would drop by around .08V and stick there temporarily. I then proceeded to disconnect power and ground to the head unit and wideband individually. I noticed when I had power connected to wideband, and connected the ground, voltage would drop by around .10 rapidly, then when I took the ground off, it'd climb back up, connect ground, voltage back down and it sticks at a certain voltage. I did the same with the headunit and it didn't have nearly the same symptoms. So I immediately thought the wideband to be suspect. So I hooked up jumper cables again, started the car, took off the cables and monitored the voltage with the grounds taken off both the headunit and wideband at the same time, but with their power wires still connected, and the voltage was STILL dropping. I took off power to the headunit and same deal. I however didn't take the power wire off the wideband yet, but I figured that'd be a lost cause. So right now, I'm at a standstill and more confusion. I'll start tracing more wires when I have more free time. But as off now, I couldn't visibly see any exposed wires. Edited May 20, 2011 by LoneStarS30Z Quote Link to comment Share on other sites More sharing options...
rsicard Posted May 20, 2011 Share Posted May 20, 2011 I had the same idea as you just a few minutes ago about disconnecting things. The battery read 13.30V this time with the jumper cables. Before that though, I had the multimeter propped up still reading the battery while I turned ACC on and started disconnecting things. I disconnect power and ground to the head unit and wideband gauge. When I went from having no power applied, to power applied, the voltage would drop by around .08V and stick there temporarily. I then proceeded to disconnect power and ground to the head unit and wideband individually. I noticed when I had power connected to wideband, and connected the ground, voltage would drop by around .10 rapidly, then when I took the ground off, it'd climb back up, connect ground, voltage back down and it sticks at a certain voltage. I did the same with the headunit and it didn't have nearly the same symptoms. So I immediately thought the wideband to be suspect. So I hooked up jumper cables again, started the car, took off the cables and monitored the voltage with the grounds taken off both the headunit and wideband at the same time, but with their power wires still connected, and the voltage was STILL dropping. I took off power to the headunit and same deal. I however didn't take the power wire off the wideband yet, but I figured that'd be a lost cause. So right now, I'm at a standstill and more confusion. I'll start tracing more wires when I have more free time. But as off now, I couldn't visibly see any exposed wires. What is the item that you are cooling the "Head Unit"??? Please use the proper terminology such that appropriate advice can be issued. It sounds as though the Alternator is good but the wiring is faulty and not connecting the alternator to the battery properly. Do you have the wiring diagram for the 240Z? What is the "Digital Gauge"??? What does this gauge indicate? The 240Z has the ammeter in series with the alternator and the battery to measure charge/discharge current. What is the ammeter indicating throughout all these exercises? An appropriately charged battery should be slightly greater than +12 volts. When cranking the engine for starting the voltage should not go lower than 8 volts DC. If it goes lower there are bad cells in the battery. When the alternator is initially charging after engine start, the alternator voltage should be +14.x volts. As the battery attains a charge the alternator voltage should taper off somewhat from +14v yet still stay above +12v. The newer alternators need only a small amount of current from the battery to provide excitation for the alternator field to cause it to generate 12 - 14 vdc. There may be an excitation return (2 wire excitation) to ground or battery negative to complete the circuit. Normally the case of the alternator is the return or ground path for both excitation and heavy current to charge the battery. The other heavy post or connection on the alternator connects back to the battery through a heavy current (low or no resistance to current flow) fused wire. Older alternator charging systems had more (complicated) wiring than newer charging systems. Hope this helps. Will look at the 240Z wiring diagram to see which OLD alternator system wiring IS NOT NEEDED. Quote Link to comment Share on other sites More sharing options...
billseph Posted May 20, 2011 Share Posted May 20, 2011 The "head unit" is the reciever for his stereo system...the thing you put CD's into. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted May 21, 2011 Share Posted May 21, 2011 I think you need to start your testing all over again. Check battery voltage without using jumper cables or a jump box connected to the battery. Battery voltage should be 12volts. If you don't have this have the battery charged. Get the car started and check the charging voltage at the battery. Should be more than 13 volts with the engine running. If not, figure out why the alternaor is not charging. You don't check for a system draw the way your checking it, I would start from scratch. I think your confusing yourself. Quote Link to comment Share on other sites More sharing options...
rsicard Posted May 21, 2011 Share Posted May 21, 2011 I think you need to start your testing all over again. Check battery voltage without using jumper cables or a jump box connected to the battery. Battery voltage should be 12volts. If you don't have this have the battery charged. Get the car started and check the charging voltage at the battery. Should be more than 13 volts with the engine running. If not, figure out why the alternaor is not charging. You don't check for a system draw the way your checking it, I would start from scratch. I think your confusing yourself. First set the Multimeter on the resistance mode. Short the two meter leads together and it should read ZERO ohms (meter check). Then connect one lead to the heavy post on the alternator and the other on the Positive side of the battery. The meter should read near or at ZERO ohms. There should be a direct connection between the two with a fusible (low resistance fuse) link in-line. If that is OK then check for battery voltage on the field terminal of the alternator with the ignition key in the RUN position. The return path for both of these is the case of the alternator. If the return path is in question, attach a heavy gauge wire from the case of the alternator to the negative post of the battery and recheck the alternator heavy post/electrical terminal for something greater than +12volts with the engine running at say 2000 RPM or above idle if the two previous checks were OK. Suspect that one or both are NOT OK. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted May 21, 2011 Author Share Posted May 21, 2011 Yes head unit refers to my cd player, and my apologies, digital gauge I meant my digital water temp gauge. I will try what you've mentioned now and see what happens, but however I have an ignorant question, by field terminal you're referring to the "power" terminal that the red/white wire connects to right? Quote Link to comment Share on other sites More sharing options...
rsicard Posted May 21, 2011 Share Posted May 21, 2011 Yes head unit refers to my cd player, and my apologies, digital gauge I meant my digital water temp gauge. I will try what you've mentioned now and see what happens, but however I have an ignorant question, by field terminal you're referring to the "power" terminal that the red/white wire connects to right? The field connection on the alternator will have a lighter gauge wire with +12v on it when the ignition key is in the "RUN" position. The Red/White should be the heavier gauge wire that connects to the heavy post on the alternator. The Red/White wire is carrying the heavy charging current for the battery through the ammeter back to the battery. This is the wire which must be a very low resistance connection between the alternator and the battery positive connection. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted May 21, 2011 Author Share Posted May 21, 2011 Ok I gotcha, thanks for clearing that up for me. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted May 22, 2011 Author Share Posted May 22, 2011 Ok fellas, I put in a battery I KNOW works, it's the one I've been getting a jump from this whole time. Battery voltage w/ no ACC - 12.62v Battery voltage w/ ACC - 12.27v Battery voltage running - 12.15-12.11v With headlights on - 11.95v Parking lights - 12.06v I then revved the engine to about 6k a couple of times and the voltage shot up a bit and stuck around 12.85V. That was the last thing I did before shutting the car off and starting itb ack a couple of times to make sure I still wasn't losing voltage. Next order of business it to take back this damned Optima and get something else, throw the new battery in, go for a quick spin around the block, come back and measure voltages again. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 22, 2011 Share Posted May 22, 2011 (edited) At 6,0000 rpm, even ~1200 rpm, you should see around 14.8 volts at the battery. The older external regulators will even let up to ~15.5 through. Either your alternator or regulator is bad, or you have some wiring issues. Your assumption that the alt and battery were working correctly, back in Post #6 might be wrong. You might take the alt in to a parts store or auto shop to have it tested. If you had a bad battery, you might have damaged the alternator. Edited May 22, 2011 by NewZed Quote Link to comment Share on other sites More sharing options...
Leon Posted May 22, 2011 Share Posted May 22, 2011 The FSM has an alternator test procedure located in the EE section. Look it up in the FSM pertinent to the year of your alternator. In fact, read through the EE section on the charging system of your car as it will help you get a better grasp of what's going on and proper test procedures. Quote Link to comment Share on other sites More sharing options...
KenshinX Posted May 22, 2011 Share Posted May 22, 2011 (edited) I just got finished dealing with headaches with my charging system even after replacing a bad battery and alternator, the first issue was the battery which I expected since it was 5 years old, but I suspected that the bad alternator put it out of its misery. (It was a Walmart battery which served me well!). Next I replaced the alternator, but the reman I received from the local parts store was rubbish. Got a new one and all was well for a little while. Then it wouldn't charge again, yet the alt passed the load test every time. So, I replaced my voltage regulator got 2 for a good deal at rock auto for 20 bucks shipped wholesale closeout! But that didn't fix the charging issue; I checked my fusible links (good). Then I checked my fuses and the lid that labled the fuses seemed fishy so i referred to the FSM and sure enough for my 260z the fuse placement was completely different then what the lid the PO had in the car. Replaced the fuses with the correct rated fuses in the right spots and all was well for a week. Then it would stop charging every so often. So, I suspected the belt because it wouldn't get tight enough, but it would charge correctly sometimes. So, the parts store rep. noticed the diameter of the alt pulley on the reman and gave me a smaller belt and all was well. So the key parts to this story/nightmare is: -Check your grounds, connections etc. -Get your alternator LOAD tested. -Check your voltage regulator if you have one. -Check your fuses and fusible links. -Check your alt belt tighness. Key links: Parts: http://www.rockauto.com/ http://www.courtesyparts.com/kb_search_result.php?chassis_id=0&keywords=fusible+links&Submit_Button=Go&cat=1 FSM: http://www.xenons30.com/ http://www.xenonz31.com/s130/index.html Edited May 22, 2011 by KenshinX Quote Link to comment Share on other sites More sharing options...
rsicard Posted May 22, 2011 Share Posted May 22, 2011 Ok I gotcha, thanks for clearing that up for me. Check the items as described. YOU WILL FIND your problem. Quote Link to comment Share on other sites More sharing options...
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