Pro5 Alternator and the "computer"

[kentphoto]

I've had my 2002 P5 in the shop this week. The power was cutting out, and the battery had died.

Anyway, the shop replaced the alternator. Then said they were having problems with it. They then replaced the battery, and said there was a connection with the alternator and the computer. They said that when tested separately , the alternator was 100%. When tested with the car and the computer, the alternator wasn't functioning as well.

So I may have to replace the computer in the car as well.

Am I getting hosed? Or is there a legitimate issue with this and the P5's.

 

[basementgeek]

iirc, the P5 "computer" is sensitive to the power that it gets. Audio guys trying to upgrade to larger, more powerful alternators, have had issues. Don't quote me on this, but check to see that the new alt is close spec wise to the old one?

 

[shanep5]

my ecu is cutting out on me could the alt. be part of the problem for me? i also have 4 gauge wire running from my alt. to my battery.

 

[aMaff]

The P5 ECU does the job of a voltage regulator on the alternator. I could see this being a problem with a bad ECU, though I'd never heard of it. I'm sure you can find someone local that'll let you borrow theirs, or buy one fairly cheap in the FS forum.

 

[i12drivemyMP5]

FYI, when I replaced my alternator recently there was a bright red sticker on the new one stating that THIS ALTERNATOR NOT MEANT TO BE TESTED OFF OF THE VEHICLE.

 

[i12drivemyMP5]

The P5 ECU does the job of a voltage regulator on the alternator. I could see this being a problem with a bad ECU, though I'd never heard of it. I'm sure you can find someone local that'll let you borrow theirs, or buy one fairly cheap in the FS forum.

I was under the impression that our alternators had an internal regulator, which would help explain why it's a 170.00 item.

 

[aMaff]

I was under the impression that our alternators had an internal regulator, which would help explain why it's a 170.00 item.

negative. That's one of the reasons that kevin (kcbhiw) was having so much trouble getting a mega-squirt set up for the FS-DE, as it doesn't really have the functionality to do that.

 

[Maxx Mazda]

If you run a vreg off a '95 and up Ford Ranger you can take the ECU right out of the equation.