Voltage regulator???

[Wade Nelson]

Wade, I would think almost anything is possible with a Volvo!!

Fast, there was an Volvo TSB on it. S80. You could install a brand new battery, start the engine, and in under 10 minutes the battery would be completely flat and the engine would die.

Using a VAT-40 charging tester I measured 40+ amps coming out of the alternator at idle, except it was actually GOING INTO the alternator. Discharging the battery. The faster the alt spun the greater the drain.

Some sort of failure of the diodes, such that the alternator was SUCKING current instead of generating it.

You could also watch the battery, initially at 12.6 or so immediately head for points south when you started the motor, so CLEARLY, instead of charging, the alternator, was, at 40A+ discharging the battery.

I had never paid attention to which way I put the clamp-on cable over the alternator cable as I had never, EVER seen an alternator sucking current. Initially I saw 40A and told myself "alternator is fine!" Ten minutes out customer calls, we have to drag the car back in.

Damnedest thing I ever saw, and after 2-3 brand new batteries in less than an hour we figured it out, with the help of Alldata, which referred to a "massive alternator failure" problem on the S80's.

That much current, you would THINK the alternator would be smoking!

I tried to find the TSB for you but failed. It's out there, somewhere. S80 model.

Clearly, Mailbud needs ONE and ONLY one voltage regulator attempting to control the alternator. What he really needs is to take it to a qualified auto electrician to straighten it out, but, I get reamed every time I suggest such a thing. So I'm gonna suggest he keep fiddling with it instead. He'll either earn a tech's degree in automotive electrical engineering in the process, develop great patience, or keep the hair regrowth products industry rolling in the green as he pulls all his out.

[malibud]

Ok wade I understand your point and no I am not supporting hair regrowth products because my hair is long gone. This is a hobby for me and first time messing with anything fuel injected. I cleaned up the connections and everything has worked for the last week although I still have fuel issue but I think it may have been fixed by cleaning out the fuel pump. But I have learned a lot from you and your patience. the people at auto zone said I had a bad alternator because at idle i was only at 11 amps. wrong . After taking it out and having it tested it was fine . I found the external voltage regulator it looked new and must have been replaced along with the alternator. After cleaning up all my connections no problems so thanks for the lesson on alternators . I am not past taking to the expert but only after giving it a good try ....

[71Nissan240Z]

Your alternator has a roll on voltage that increases with rpm