Logo
FULL SITE MENU

Engine not charging and orange wire disconnected.

B

Bobbyj12

New member
Hello all, I purchased the boat last November. (1997 Regal Commadore 292, twin 5.7). The port engine is not charging 11.67v. The alternator has been tested, the batteries are brand new, I cleaned and lubed with dielectric grease all connections I could find. I swapped coils and alternator, no change. Oddly enough, the orange wire at both alternators are disconnected with black tape covering the connection. I don't know why. Would this stop the port engine from charging? If so, why would the starboard engine be charging at 13+ volts?
 
The output wire is red and it seems to be routing away from the engine and goes through a large gray wire chase on the fire wall. From there I can't seem to trace where it terminates.
 
The reason why I'm asking about the islands wire is, the port engine is not charging the battery. It registers 11.67 at the battery. The alternator was checked in it is putting out 14 plus volts. I swapped alternators with the starboard engine, I swapped the coil with the starboard engine and I get the same result. I replaced the serpentin belt because it was a bit shiny. I believe because of the charging issue it is causing issues with alarms in sensor's giving the wrong readings. As long as I'm cruising at 3100 rpm the boat runs fine but still does not charge. If I cruise at 3400 rpm after about admitted or 2, I get alarm in my oil pressure drops. I have a feeling this is all electrical related. The boat has a new oil sending unit installed.
 
bobbyj12 said:
the reason why i'm asking about the islands wire is, the port engine is not charging the battery. It registers 11.67 at the battery. The alternator was checked in it is putting out 14 plus volts. I swapped alternators with the starboard engine, i swapped the coil with the starboard engine and i get the same result. I replaced the serpentin belt because it was a bit shiny. I believe because of the charging issue it is causing issues with alarms in sensor's giving the wrong readings. As long as i'm cruising at 3100 rpm the boat runs fine but still does not charge. If i cruise at 3400 rpm after about admitted or 2, i get alarm in my oil pressure drops. I have a feeling this is all electrical related. The boat has a new oil sending unit installed.
Click to expand...

you have a battery isolator!
 
Measure the output of the port alternator at a point near the alternator. If you don't have a conveninient measuring point, use a razor or exacto blade to make a small slit along the wire insulation to expose the wire enough to get a probe on it, or conversely use a sharp pin to pierce the insulation and put the meter probe on the pin. ( cover with tape when done!) With the engine running, you should see 14 plus volts. Now, measure the voltage at the "port" battery terminal. If its not the same 14 ish volts, you have a simple discontinuity between the alternator output and the battery. Per Chris, it could be an isolator, or it could be a battery switch that is defective or in the wrong position...a poor or missing connection.... whatever... volts out of alternator not getting to battery.
 
I swapped the alternator from the starboard engine. Same result.
Y focus will be on the isolator. My question, can 1 "bank" in the isolator go bad? There are 8 wires connected to it, all red of course. I'm not sure which one goes to what. I will do a continuity test to find that out.
 
Another thought, could I disconnect the red wire at the alternator and hook the orange back up to see if the charging resumes? Would that cause any harm (just for a test)?[
 
Docksidemarineservices said:
Do not cut or poke any holes in any wire on your boat.....EVER.
Click to expand...

Meter test probes with insulation piercing tips have been an industry standard longer than you've been out of diapers. In many applications, the insulation will flow back requiring no further action to be safe. In a critical application, tape ( Silicone rescue, i.e self fusing, tape. not electrician's tape) will repair the wire to its original condition. For a one time test, a pin from a sewing kit will work just fine.
 
sandkicker said:
Meter test probes with insulation piercing tips have been an industry standard longer than you've been out of diapers. In many applications, the insulation will flow back requiring no further action to be safe. In a critical application, tape ( Silicone rescue, i.e self fusing, tape. not electrician's tape) will repair the wire to its original condition. For a one time test, a pin from a sewing kit will work just fine.
Click to expand...

Sorry, No where in any Mercruiser manual does it say to use a wire piercing probe. We have breakout boxes for this type of testing.

NEVER POKE HOLES IN YOUR WIRES......PERIOD.
 
Bobbyj12 said:
Another thought, could I disconnect the red wire at the alternator and hook the orange back up to see if the charging resumes? Would that cause any harm (just for a test)?[
Click to expand...

Negative. Do not hook up the orange wire, the orange wire is not hooked to anything on either end if you have a battery isolator.
 
Under most circumstances the orange wire is the output of the alternator going to the battery. The starter lug just happens to be a convenient termination point as the electrons will flow out to the battery via the large red starter wire connected to the battery.
You owe it to yourself to find out what's going on with your charging system. Relying on what a previous owner, or even the factory, did can lead to a false sense of security.
If you do have a battery isolator, it will drain a bit of juice due to heat loss. These types of setups are obsolete and will result in a lot of problems, as you are discovering.
If you are uncomfortable with electrical work (lots of people are) then you might want to consult with a marine electrician. They will help assess your charging needs, develop a system for you and install it according to ABYC standards. It's well worth the expense and is 100 percent safety related cost so the spousal unit will have no argument against it!

Oh and yeh don't poke holes in your wiring. It will let all the smoke out.
 
Personally I would remove the wire now at the alt output post, test the Orange wire for battery voltage to make sure its hooked to the starter and hook it back up to the output post and eliminate the isolator , do the same for the other engine also.
There more trouble than there worth.
Most likely you do not have true dual, independent engine systems either with independent charging systems
 
iso2alt3bat.jpg
 
Bobbyj12 said:
The orange wire is hooked to the starter. The other end at the alternator has black tape on it.
Click to expand...

When the battery isolator was installed the wire was supposed to be disconnected from the starter and taped back into the harness. Someone f-ed up.

So you can hook it back to the alt and bypass the isolator.
 
I figured it out. It was a bad wire from the isolator to the breakers on the port engine. I replaced the wire and now the gauge is reading 12+ and the battery is reading 13+. Next I will look at the gauge.
 
Back
Top