goinhungry
Seaman
- Joined
- Sep 8, 2005
- Messages
- 71
I'm about ready to attempt fixing my wiring / alternator short on my '89 3.0L Merc w/ 4 wire mando. Lots of guys have pitched in and helped out in the past with other issues that I've had (including this one), so I'm looking to get some advice that's specific to addressing this one so I can hopefully get it running again before spring. 
<br /><br />The history is this - last year, wires were reversed when hooking up the battery - smoked the alternator. Rebuilt (diff. one) is now in it, but tried hooking it up/running again and it started to heat up the battery (without the belt spinning the alternator pulley), so I quickly disconnected it again. All wiring is at least 5 years old, so I'm going to remove the battery cables, etc and replace with new ones, clean all connections, etc., but my question is how do I (limited mech./elec. experience..) diagnose if the alternator is the problem. The rebuilt has different color wires coming out of the regulator than my boat, although each side has a red, so I hooked up the reds, then connected the other two together. (Ground and exc. were hooked back up as per original...) Is there a way to test the 2 wires going into the regulator to determine which should be pos.? What's the other color for, since the alternator has a sep. ground wire? (sorry, I'm stupid...) Finally, is there a way to determine which wire going into the alternator should be which - I'd like to elminate the possibility that the wires are switched, and therefore causing a short inside the alternator itself. <br /><br />As always, sorry for the long post, but I know that more detail is better than less, and thanks for the info/advice!
<br /><br />The history is this - last year, wires were reversed when hooking up the battery - smoked the alternator. Rebuilt (diff. one) is now in it, but tried hooking it up/running again and it started to heat up the battery (without the belt spinning the alternator pulley), so I quickly disconnected it again. All wiring is at least 5 years old, so I'm going to remove the battery cables, etc and replace with new ones, clean all connections, etc., but my question is how do I (limited mech./elec. experience..) diagnose if the alternator is the problem. The rebuilt has different color wires coming out of the regulator than my boat, although each side has a red, so I hooked up the reds, then connected the other two together. (Ground and exc. were hooked back up as per original...) Is there a way to test the 2 wires going into the regulator to determine which should be pos.? What's the other color for, since the alternator has a sep. ground wire? (sorry, I'm stupid...) Finally, is there a way to determine which wire going into the alternator should be which - I'd like to elminate the possibility that the wires are switched, and therefore causing a short inside the alternator itself. <br /><br />As always, sorry for the long post, but I know that more detail is better than less, and thanks for the info/advice! 