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Old 09-19-2007, 10:07 AM
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azurite300E azurite300E is offline
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Quote:
Originally Posted by oldiesel View Post
I dont know what diode trick you tried but i have always been able to get regulator voltage up .5 volt by putting a diode in the wire to D+,perhaps there is something different about your alternator but it has always worked for me.you are aware that the diode has to be placed in the correct polarity? Connect the diode to the wire that goes to D+ and use a test light to be sure the voltage is getting thru the diode before you connect to the D+ terminal. My $.02 Don
Hi Don,

Thanks for sharing your experiences with the diode mod. In any case it makes perfect sense and it should work, because the regulator would see between 0.5~0.6V LESS due to the diode's voltage drop.

When I first did my own test, I followed the instructions found in an article that involved in this case lifting the GROUND terminal of a Bosch regulator through a diode, which technically should attain similar results. But for some reason as I mentioned earlier, it did not work for me, and I did double check that the regulator body (ground connection) was completely isolated. I'm guessing the regulator circuit itself didn't like this, and stopped working altogether, there was no voltage output from the alternator at all. The article is here:

http://www.detomaso.nu/~thomast/alternator/

At the time I though about connecting the diode in series with the D+ terminal as you suggested, a much more elegant way to trick the regulator. But in my particular case it would be very tricky to do. There is already very limited space in the area where the regulator is mounted inside the alternator, and the regulator D+ makes contact with a hidden terminal inside the alternator. Furthermore to complicate matters, the D+ on the regulator is kind of a springy tongue that compresses over the hidden terminal inside the alternator, so no way to install the diode anywhere in between.

Someone suggested using an old gutted regulator just to get at the terminals inside the alternator, attach two cables to it, and use an external 14.4~14.5V regulator. This might have worked for me, but I neither have a bad regulator on hand (don't even want to consider gutting a good one), and I'm not too fond of the idea of using an external regulator.

Anyway, thanks again, appreciate your two cents.
-Alex
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