beermanpete Posted May 5, 2014 Share #37 Posted May 5, 2014 It sounds like you are making progress, which is good to hear.The charging system draws about 2.5 amps maximum. The 1156 bulb is about a 2 amp load normally, so the bulb will light trying to power the charging system, but not at full brightness. To test the regulator and alternator separately, start by leaving the regulator connected but disconnect the 2-wire connector from the alternator. The 1156 should stay dark if the regulator is good. Next, with the 2-wire connector removed and the engine off, use the ohmmeter and measure the resistance from the F terminal (on the alternator) to ground. The resistance should be about 5 ohms for the 40 amp alternator and 4.5 ohms for the 60 amp alternator. Link to comment Share on other sites More sharing options...
Da Flash Posted May 7, 2014 Author Share #38 Posted May 7, 2014 It sounds like you are making progress, which is good to hear.The charging system draws about 2.5 amps maximum. The 1156 bulb is about a 2 amp load normally, so the bulb will light trying to power the charging system, but not at full brightness. To test the regulator and alternator separately, start by leaving the regulator connected but disconnect the 2-wire connector from the alternator. The 1156 should stay dark if the regulator is good. Next, with the 2-wire connector removed and the engine off, use the ohmmeter and measure the resistance from the F terminal (on the alternator) to ground. The resistance should be about 5 ohms for the 40 amp alternator and 4.5 ohms for the 60 amp alternator.OK, I did the 280zx altenator upgrade eliminating the regulator and replacing it with the reg plug with pins 1 and 2 jumpered and installing a diode between pins 5 and 6. The light still comes on but not as bright. The light will go out if I unplug the altenator "T" plug. On my altenator there is no "F" terminal but from all the pics I've seen, it looks like the vertical leg on the "T" connector. If I measure ohms between that pin and ground I get a reading of ~1.200 with my meter set to 2K. Is this the F terminal that you are referring to?? Link to comment Share on other sites More sharing options...
Zed Head Posted May 7, 2014 Share #39 Posted May 7, 2014 The light still comes on but not as bright.Is this with the engine running, with the key On, or with the key off? Link to comment Share on other sites More sharing options...
Da Flash Posted May 7, 2014 Author Share #40 Posted May 7, 2014 Is this with the engine running, with the key On, or with the key off?With the key ON. Link to comment Share on other sites More sharing options...
beermanpete Posted May 7, 2014 Share #41 Posted May 7, 2014 OK, I did the 280zx altenator upgrade eliminating the regulator and replacing it with the reg plug with pins 1 and 2 jumpered and installing a diode between pins 5 and 6. The light still comes on but not as bright. The light will go out if I unplug the altenator "T" plug. On my altenator there is no "F" terminal but from all the pics I've seen, it looks like the vertical leg on the "T" connector. If I measure ohms between that pin and ground I get a reading of ~1.200 with my meter set to 2K. Is this the F terminal that you are referring to??My suggestions were for the orignal alternator with the external regulator. They do not apply to the internal regulator type. The behavoir you describe is typical for a properly functioning internally regulated alternator. When you start the engine and the alternator begins to charge the light will go out. Link to comment Share on other sites More sharing options...
Da Flash Posted May 10, 2014 Author Share #42 Posted May 10, 2014 My suggestions were for the orignal alternator with the external regulator. They do not apply to the internal regulator type. The behavoir you describe is typical for a properly functioning internally regulated alternator. When you start the engine and the alternator begins to charge the light will go out.Success at wast, It turned out to be the voltage regulator!! I can now start the engine and NOT have the fuse blow. I'm still working on getting the engine to turn off when I turn the key off but, I'm starting to think that it's the diode that I used. Is there a specific diode that is to be used?? Anyways, now to remove the dash and install all of the heater/defrost pieces and re install the dash.Thanks for your patience with the electrically challenged! Link to comment Share on other sites More sharing options...
beermanpete Posted May 11, 2014 Share #43 Posted May 11, 2014 Success at wast, It turned out to be the voltage regulator!! I can now start the engine and NOT have the fuse blow. I'm still working on getting the engine to turn off when I turn the key off but, I'm starting to think that it's the diode that I used. Is there a specific diode that is to be used?? Anyways, now to remove the dash and install all of the heater/defrost pieces and re install the dash.Thanks for your patience with the electrically challenged!Great!The diode needs be installed a particular way. Try turning it around. As for the type of diode, any 50 Volt (or higher) diode rated for 6 amps or more should work. Also, diodes don't like high temperatures so be carefull when soldering it to the wires. Use a heatsink on the leads (by lightly squeezing the diode lead with needle nose pliers between the solder joint and the diode) to keep the heat out of the diode. Too much heat will short out the diode. Link to comment Share on other sites More sharing options...
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