Charging problem..Merc 160

[thunderroad]

My amp gauge always ran just a little to the right of center but the other day I saw it flickering back and forth and now it stays right in the center. Turn on some lights and it drops to the left just a little but doesn't come back. I took the alternator off and had it checked. It was fine. With the engine running, I tested the field wire at the alternator and it showed no measureable voltage. I tested the white wire on the plug at the regulator and it had 12 volts so I thought the regulator was bad. I swapped it out with one that I knew was good and still got nothing. The alternator isn't putting out anything. Registers 12.2 volts. Run a jumper wire from the battery to the field terminal on the alternator and the alternator kicks in and puts out 15+ volts plus the needle on the amp gauge reads about +15. What's going on here? I'm scratchin my head. Checked all the basic stuff I could think of. Battery checks out ok and cables are clean and tight. (no wing nuts) All connections look ok. It has an external transistor regulator. <br />SN 2497444

 

[Bt Doctur]

Re: Charging problem..Merc 160

you got a real oldie there. Id update to the GM single wire alt. <br />reg. is internal and only a hot and ground wire to deal with.

 

[thunderroad]

Re: Charging problem..Merc 160

I thought about that. The alt and regulator seem to check out though. <br />If I did that, how exactly would I wire it up? What becomes of the wires that go to the present regulator?