eastcoastz

@jpc3006 Thanks for the info! I ended up going back with the 0.6 Ohm Flamethrower II coil with a 2.4 Ohm ballast resistor. Knock on wood, the tach is been working well with that setup. The ballast resistor is part F1104 if anyone needs it in the future.

I switched back to the 3 Ohm Flamethrower I coil that I had laying around (without the ballast resistor) and now the tach works better. I like that the .6 Ohm Flamethrower II is higher voltage so I might try a 2.4 Ohm ballast resistor with the .6 Ohm coil. I’ll keep you posted.

I know there have been a lot of topics on this but most of them are old so I thought I would start a new one to explain what’s going on and to see if there are any new ideas/solutions. I installed a Pertronix Ignitor II with a Flamethrower II (0.6 Ohm) coil. According to Pertronix, this is a matched pair. The car (1971 240z) has and continues to great with this setup. The issue I’m having is with the tach. When I first installed this Pertronix set, I had an issue with the tach not going above 3000 rpm. The car has no issue revving well above that, but the tach would stop at 3000 rpm and sometimes would even start going backwards. I talked with Pertronix tech support and they recommended that I put in a ballast resistor which I did and then the tach started working perfectly (for weeks). Fast forward to today, the tach started doing the same thing (stalling at 3000 rpm) even with the ballast resistor. At random times it will go above 3000 rpm if I rev it up in 2nd gear for instance but even then the needle bounces around and then when I get to a cruising speed it stays stuck at 3000 rpm even if I push it in 4th. I can’t imagine it’s related but the only recent change I made was I swapped out the original 40A alternator for the 60A alternator from the 280ZX. Any ideas why the tach keeps stalling at 3000 rpm? What could I do to make it reliable again? The tach had no issues with the points installed. Thank you!

Third time's a charm... so the first one had a bad diode (or two or three) and caused the battery to drain.... the second one had a bad voltage regulator... and the third one finally appears to be working properly. Remy/BBB definitely has some quality assurance issues and I would highly recommend getting a "NEW" one instead of re-manufactured if you have the chance. If I had to do it over again, I would NOT go with a re-manufactured alternator. Thanks all for your help!

Unfortunately the old external VG was melted so I threw it out. 😞 I guess I’ll just have to wait for the replacement. If this 3rd one is defective for some reason, I might just have to pay more for a new one vs. the remanufactured one. Hopefully the new, new ones are better quality and tested more thoroughly.

I was probing the yellow wire with it plugged into the alternator with the car on. Can it damage the wiring (or anything electrical in the car) if I drive it like this until the replacement one arrives?

Thank you @Dave WM Yeah my ammeter is going crazy non-stop when the RPMs are below 2500. Here a video of what mine is doing: https://youtube.com/shorts/YmhfYndqG4E?feature=share I talked with Remy/BBB (the supplier/refurbisher of these alternators)... described the issue to them and they said it sounds like a bad internal voltage regulator. Since this is the second bad unit from them, the guy I talked to said he is filing a QA report to his team. Can it potentially damage the wiring/electrical in the car if I continue to drive it like this (until the third (new) alternator arrives)?

When I say that the E-Brake light is pulsating... a better word for it, would be that it is slightly flickering when the ammeter needle is dancing. It's not pulsating to the point that it is on a standard repetition like a blinker/flasher. Nor is the needle dancing with any repetition... it just goes all crazy when idling and gets a little better when the engine is revved up. I also forgot to mention that I currently have it idling at about 900-950 rpm.

@SteveJ Thanks so much for your help... I really appreciate it! I apologize for the delay in getting back to you. I just had a chance to run through the tests and here are the results: Black/white wire has no voltage when the key is off Yellow wire on the T connector has 13.27 volts with the key off Yellow wire on the T connector dances around between 14.8 - 15.1 volts when the car is on (idling) I no longer appear to have the issue with the battery draining while sitting, but I do still/now have this issue with the ammeter dancing. When idling the ammeter needle sweeps the entire gauge over and over. Once I rev up to about 2500 rpm, the needle dancing settles down a little but still occurs. I also noticed that the E-Brake light (in the speedometer) is pulsating when idling. Does this sound to you like I have yet another bad (new) alternator?

... so the initial impression is that the new alternator is not draining as fast as the first "new" one. I still need to test the voltage on the battery a little later again. One odd thing that I've noticed with this second new one is that sometimes at idle, the ammeter (in the car) goes a crazy/wonky... the needle moves around side to side from like middle of the left to middle of the right (like a seismic needle... haha). If I give it a little gas while it's doing this, the needle goes back to center and stays there. Has anyone else seen this before?

That makes totally sense about the old wiring... I've added a few additional electrical components (Petronix Ignitor II, aftermarket radio, NISMO fuel pump, etc.) and I read that the 60A alternator was a common upgrade that seemed easy enough to try. I still need to find some time to test the wires for voltage as recommended, so I'll write back on this thread soon with the results.

Thank you. I’ll run some test as soon as I can and respond back. If I’m reading the wiring diagram correctly it looks like the L/S was originally F/N and it looks like those wires just go between the alternator and the (now absent) external voltage regulator. That being said, I’m not sure what you mean about the L circuit since the L (former F) wire just ends at the voltage regulator. I never had any battery drain issues with the OEM alternator (and external voltage regulator). I just thought it would be a good idea to upgrade to a 60A alternator and I immediately had this battery drain issue. Thank you for all of your help!

Thanks so much! I have to wait for the replacement alternator (had to send the first one back already)... so I'll test that black/white wire when I connect up the new one and I'll let you know what I find.

@Zed Head Yeah I've been using a meter to test the wiring... that's how I found that the battery was dropping voltage when the alternator is connected. I had read that I could put the meter on the diode setting and put one lead on the battery output (on the alternator) and the other lead on the casing of the alternator. This is giving a reading of around 1250... I read that if it's a diode in the alternator that's causing the drain, then this reading should be a lot lower (like 250), but some people were also saying this may not be a fool proof way of testing the diodes because an alternator can have 6 (maybe more) diodes inside. @SteveJ I pulled the connector (with the jumped wires) off of the engine harness and the diode tested fine (got a reading of about 580) when I put the meter probes on the pins/blades (that go into the engine harness). Are you saying that I should probe the black/white wire with the "jumped" connector off (in order to test the diodes inside of the alternator)?

Thank you. I have a 1971 240z.... I purchased a 60A 280ZX alternator (BBB Industries - Part# 14592).