I'm replacing a Volvo Penta TAMD74EDC 24v alternator and when I received a "compatible" replacement, it is missing a 4th wire which comes out of the regulator. The photo is my existing alternator; the D+ and B+ wires have already been removed. I'm assuming the small gauge red wire coming out of the regulator is voltage monitor to my helm monitor/light. Can anyone confirm? If so, can I just place this wire on the B+ terminal?
With such little information, alternator model numbers (in & out), no schematic or ships install diagrams,, it will be hard for anybody to answer this question, except maybe from the guy that sold you the "compatible" replacement. Your experimenting with electricity and expensive equipment and no DIY warranties. I hope you have good luck.
The existing alternator model number is provided (Valeo H642509A) and if I was experimenting, I'd just install the replacement and cross my fingers, which I won't do. I have no schematic/ships diagram, or I wouldn't be here reaching out in the hope of constructive comments. Valeo has no cross reference for this model. As for the "replacement", the model number is irrelevant. I've also reached out to Viking and Volvo. Further research tells me the small gauge red wire leading into the regulator is a remote sense from the battery-side of the isolators. I'm going to ping that out to confirm.
Capt CG, Ralph is generally helpful but his humor might be hard to read. I know you cross posted to other forums in search of answers. We run a tight ship but sometimes any crew can become mutinous. Hopefully you will find more constructive guidance moving forward.