metalmonkey47 Posted March 30, 2011 Report Share Posted March 30, 2011 I keep having a problem on my 210. I've noticed that my alternator is charging at about 15.3 volts at idle, but strangely, on occasion I notice at idle the alternator stops charging until about 3500 RPM. The alternator is BRAND NEW and I just put it on yesterday. I've gone through three different alternators trying to solve this problem and it continues, so the issue must not be with a faulty alternator. It's IR, so it shouldn't be overcharging, but it is. Also, it's not the stock 50 AMP, it's a 60amp Z car alternator. Any ideas? Quote Link to comment
datzenmike Posted March 30, 2011 Report Share Posted March 30, 2011 You've changed the alt several times and no luck, so this would indicate the alt may not be at fault. What's left is.... everything else! Seriously, remove, clean and tighten both ends of both battery cables. Make sure or make a 10 gauge ground strap from the block to the body sheet metal. (or from the neg post to the sheet metal) Remove and clean the charge wire on the alt. and make sure the two wire T plug is tight and secure. Last inspect the fusible link for internal damage or bad connection. It will be connected (one way or the other) to the battery positive post. On th truck it's out in the open, but on the 210 may be under cover where all the relays are kept. Even if this does not help, it won't hurt to do. I guess the only thing left is the battery. Can you borrow one and see if the problems go away? Quote Link to comment
Skib Posted March 30, 2011 Report Share Posted March 30, 2011 did it origonally come with an externally regulated alt? Quote Link to comment
datzenmike Posted March 31, 2011 Report Share Posted March 31, 2011 '81 would have been IR. The 280z could be either depending on year. Nissan alts. have a foil label and on it will be LT if external regulated and LR if internal. Usually they were IR after '78. Quote Link to comment
metalmonkey47 Posted March 31, 2011 Author Report Share Posted March 31, 2011 I've been through most of that already, but I suppose I could have always over looked something. I don't have a fusible link, so I'm assuming the PO removed it. I traced the wiring diagram and it seems correct, so It appears the link may have just been removed. I considered putting in a small auto reset circuit breaker. The battery is a brand new red top Optima, so I'm gonna go out on a limb here and assume it's not the problem, but I'll swap back in my other battery and see it theres a difference. Quote Link to comment
metalmonkey47 Posted April 1, 2011 Author Report Share Posted April 1, 2011 did it origonally come with an externally regulated alt? '81 would have been IR. The 280z could be either depending on year. Nissan alts. have a foil label and on it will be LT if external regulated and LR if internal. Usually they were IR after '78. oops, overlooked those posts. Original was IR, and the Z car alt now is IR. I even check to confirm and the regulator is visible. It's now charging at 16 volts when warm. I've double checked EVERY wire and it's all fine. Next idea? It's still dropping to 12-13 volts at idle, and it makes me really nervous about driving it. This was sudden. It never charged like this before a few weeks ago. NOTHING changed that could be responsible. Quote Link to comment
Rob W. Posted April 1, 2011 Report Share Posted April 1, 2011 Just a thought, is it possible the meter you're reading the voltage with is bad? Try a different meter maybe. Quote Link to comment
metalmonkey47 Posted April 1, 2011 Author Report Share Posted April 1, 2011 Just a thought, is it possible the meter you're reading the voltage with is bad? Try a different meter maybe. My meter is my Prosport gauge. My thought at first, but I checked it with a volt meter and it confirmed it. Also, my recent alternator has developed a slight whine. Not sure it that's relevent. Quote Link to comment
Rob W. Posted April 1, 2011 Report Share Posted April 1, 2011 Whines are relevant. Is the pulley size the same?? Quote Link to comment
ggzilla Posted April 4, 2011 Report Share Posted April 4, 2011 my recent alternator has developed a slight whine Your brand new alternator may be bad. A bad diode will create a an eletrical type whine. Take it to the store, and insist they use a voltmeter to test it, not just a go/no-go tester. Quote Link to comment
metalmonkey47 Posted April 11, 2011 Author Report Share Posted April 11, 2011 Whines are relevant. Is the pulley size the same?? Yup, same pulley size, so it's not overdriving it. Your brand new alternator may be bad. A bad diode will create a an eletrical type whine. Take it to the store, and insist they use a voltmeter to test it, not just a go/no-go tester. I got it from Autozone where I work, so I've pretty much checked it every way I can. I've put on 4 different alternators and they've all done this, so I have a feeling the issue is on the car. I started her up today (been out of town for a WEEK) and it's not charging. It's also flaming hot after a few minuets, and stinks like an elephants ass, so I have a feeling I've burned out the alternator. Quote Link to comment
Datsfrodo Posted April 11, 2011 Report Share Posted April 11, 2011 Just throwing it out there, tension on the alt belt nice and tight? Quote Link to comment
metalmonkey47 Posted April 11, 2011 Author Report Share Posted April 11, 2011 Just throwing it out there, tension on the alt belt nice and tight? Yeah, I've found the problem (kinda) I unwrapped ALL the wiring under the hood and back through the firewall and discovered the fucking PO cut out a harness from another car and spliced it into this car and tried to hide it I'm uber pissed. It's HORRIBLE. Quote Link to comment
Datsfrodo Posted April 12, 2011 Report Share Posted April 12, 2011 Good you caught it now, instead of driving down the freeway and smelling a fire. Quote Link to comment
DanielC Posted April 21, 2011 Report Share Posted April 21, 2011 I have found out on my 521 that I swapped a 50 amp internal regulator alternator on will charge without the two small wires hooked up, but it does not control the voltage very well. I believe the alternator uses the "S" terminal to "sample" the voltage at where ever you hook it up at. Without this wire, the alternator guesses badly on what voltage it is making. Check the connections on the wire going to the "S" terminal on the alternator. Quote Link to comment
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