Difference in engine voltage while running
04-24-2016, 10:12 PM
#11
Registered
iTrader: (3)
Well, I think I have it figured out. Had both engines on the hose in my driveway, and was second guessing myself about what I saw yesterday....a difference in voltage from side to side.
The starboard engine battery was 12.98 v at rest. After starting, it jumped to 14.65 at the battery and 13.8 at the gauge on the helm. I was puzzled...but thought I had the engines switched in my mind.
Hooked the hose to the port engine and with engine off, batt was at 12.55v, and after starting, it went to 14.46 at the battery, and 13.8 on the gauge at the helm. Now I was really confused. Put hose back on starboard, and low and behold, I did have a voltage drop.....when the Corsa exhaust is engaged. All 4 solenoid are tied to the starboard power and switch....as you would expect I guess.
After unhooking all of the solenoids and looking for one that was misbehaving, I found that they all will drop the voltage from the gauge on the helm, you start at 13.8, manually plug one in, drops to 13.5, then 13.1, than 12.9, then 12.8. Reverse the whole process(unplug all, and start from the other side), and you get identical v drops. Plug any one in...and you get a drop from 13.8 to 13.5. So......all of them are the same.
What is weird, is that the battery voltage through this whole thing is 14.4v....so there is no problem with draining the battery. It must be that gauge uses an upstream source, after the accessories. Probably great for battery health, but not good for things that like 14v....like amps etc.
In any case, I am no longer worried about it too much, unless someone out there reads this and has a concern.
Thanks for the ideas...that is what is great about this site.
The starboard engine battery was 12.98 v at rest. After starting, it jumped to 14.65 at the battery and 13.8 at the gauge on the helm. I was puzzled...but thought I had the engines switched in my mind.
Hooked the hose to the port engine and with engine off, batt was at 12.55v, and after starting, it went to 14.46 at the battery, and 13.8 on the gauge at the helm. Now I was really confused. Put hose back on starboard, and low and behold, I did have a voltage drop.....when the Corsa exhaust is engaged. All 4 solenoid are tied to the starboard power and switch....as you would expect I guess.
After unhooking all of the solenoids and looking for one that was misbehaving, I found that they all will drop the voltage from the gauge on the helm, you start at 13.8, manually plug one in, drops to 13.5, then 13.1, than 12.9, then 12.8. Reverse the whole process(unplug all, and start from the other side), and you get identical v drops. Plug any one in...and you get a drop from 13.8 to 13.5. So......all of them are the same.
What is weird, is that the battery voltage through this whole thing is 14.4v....so there is no problem with draining the battery. It must be that gauge uses an upstream source, after the accessories. Probably great for battery health, but not good for things that like 14v....like amps etc.
In any case, I am no longer worried about it too much, unless someone out there reads this and has a concern.
Thanks for the ideas...that is what is great about this site.
04-25-2016, 08:06 AM
#12
Registered
Well, I think I have it figured out. Had both engines on the hose in my driveway, and was second guessing myself about what I saw yesterday....a difference in voltage from side to side.
The starboard engine battery was 12.98 v at rest. After starting, it jumped to 14.65 at the battery and 13.8 at the gauge on the helm. I was puzzled...but thought I had the engines switched in my mind.
Hooked the hose to the port engine and with engine off, batt was at 12.55v, and after starting, it went to 14.46 at the battery, and 13.8 on the gauge at the helm. Now I was really confused. Put hose back on starboard, and low and behold, I did have a voltage drop.....when the Corsa exhaust is engaged. All 4 solenoid are tied to the starboard power and switch....as you would expect I guess.
After unhooking all of the solenoids and looking for one that was misbehaving, I found that they all will drop the voltage from the gauge on the helm, you start at 13.8, manually plug one in, drops to 13.5, then 13.1, than 12.9, then 12.8. Reverse the whole process(unplug all, and start from the other side), and you get identical v drops. Plug any one in...and you get a drop from 13.8 to 13.5. So......all of them are the same.
What is weird, is that the battery voltage through this whole thing is 14.4v....so there is no problem with draining the battery. It must be that gauge uses an upstream source, after the accessories. Probably great for battery health, but not good for things that like 14v....like amps etc.
In any case, I am no longer worried about it too much, unless someone out there reads this and has a concern.
Thanks for the ideas...that is what is great about this site.
The starboard engine battery was 12.98 v at rest. After starting, it jumped to 14.65 at the battery and 13.8 at the gauge on the helm. I was puzzled...but thought I had the engines switched in my mind.
Hooked the hose to the port engine and with engine off, batt was at 12.55v, and after starting, it went to 14.46 at the battery, and 13.8 on the gauge at the helm. Now I was really confused. Put hose back on starboard, and low and behold, I did have a voltage drop.....when the Corsa exhaust is engaged. All 4 solenoid are tied to the starboard power and switch....as you would expect I guess.
After unhooking all of the solenoids and looking for one that was misbehaving, I found that they all will drop the voltage from the gauge on the helm, you start at 13.8, manually plug one in, drops to 13.5, then 13.1, than 12.9, then 12.8. Reverse the whole process(unplug all, and start from the other side), and you get identical v drops. Plug any one in...and you get a drop from 13.8 to 13.5. So......all of them are the same.
What is weird, is that the battery voltage through this whole thing is 14.4v....so there is no problem with draining the battery. It must be that gauge uses an upstream source, after the accessories. Probably great for battery health, but not good for things that like 14v....like amps etc.
In any case, I am no longer worried about it too much, unless someone out there reads this and has a concern.
Thanks for the ideas...that is what is great about this site.
04-25-2016, 08:27 AM
#13
Platinum Member
Platinum Member
iTrader: (6)
Those solenoids draw a bunch of current when engaged
04-25-2016, 08:45 AM
#15
Registered
iTrader: (1)
Four solenoids can yank your voltage down that much? I would consider there is still an issue - the alt should be able to maintain voltage with that load. Otherwise it is badly undersized, which I consider unlikely from the factory. Check all connections for voltage drop while operating to find the culprit.
I think this is pretty normal (but not really acceptable) of the voltage drop many boats see up at the helm because of thin gauge wire(s) bringing the battery power up there.
edit in: too many power robbing things wired up at dash power source for the battery + wires coming up to the helm.
Last edited by SB; 04-25-2016 at 08:53 AM.
04-25-2016, 03:13 PM
#16
Registered
I read it different, I believe He said the actual battery volt stays same, but gauges go down in volts.
I think this is pretty normal (but not really acceptable) of the voltage drop many boats see up at the helm because of thin gauge wire(s) bringing the battery power up there.
edit in: too many power robbing things wired up at dash power source for the battery + wires coming up to the helm.
I think this is pretty normal (but not really acceptable) of the voltage drop many boats see up at the helm because of thin gauge wire(s) bringing the battery power up there.
edit in: too many power robbing things wired up at dash power source for the battery + wires coming up to the helm.
04-26-2016, 10:46 AM
#17
Registered
Thread Starter
I read it different, I believe He said the actual battery volt stays same, but gauges go down in volts.
I think this is pretty normal (but not really acceptable) of the voltage drop many boats see up at the helm because of thin gauge wire(s) bringing the battery power up there.
edit in: too many power robbing things wired up at dash power source for the battery + wires coming up to the helm.
I think this is pretty normal (but not really acceptable) of the voltage drop many boats see up at the helm because of thin gauge wire(s) bringing the battery power up there.
edit in: too many power robbing things wired up at dash power source for the battery + wires coming up to the helm.
05-15-2017, 09:18 AM
#18
Registered
Thread Starter
Hi all, I am going to resurrect this thread.
In short recap of what is going on.
1) Alternators and batteries are both working well. Batteries at 12.3-12.6v without engines running. 14.1-14.6v when engines running. Conclusion....batteries and alternators are fine. This is verification by using a good handheld multimeter
2) When a large load(specifically the Captain Call switchable exhaust) on, the voltage reading on the helm, AND Garmin(via NMEA2000) shows that the Port voltage drops to around 12v. When the CC is off, the voltage is better...maybe 13v. Conclusion. For some reason, the NMEA AND voltage gauge on helm are NOT seeing the same voltage as the battery(which is at 14v when engines are running).
As stated earlier, I am not worried about the health of the battery and charging system...but.....why would the NMEA and the helm gauge show a low voltage? It cannot be the wiring to the helm because the NMEA does not use the same wiring(I assume).
I am looking for advice from any and all regarding how the NMEA and normal gauge is sensing voltage. Can someone let me know where the NMEA gets it's voltage? Then where the normal point of voltage sense for the helm would be? Trying to isolate why alternator and battery are fine...but the gauge for the port engine is showing low voltage.
Normally, I would not worry about the helm voltage...but as the NMEA voltage is low too....I have to believe that the engine is running off of the 12v(when Captain Call is engaged) This cannot be a good thing for the ECU and performance in general. There must be a bad connection somewhere...I am just looking for help in where to start looking.
Any help would be appreciated..
Thanks!!!
In short recap of what is going on.
1) Alternators and batteries are both working well. Batteries at 12.3-12.6v without engines running. 14.1-14.6v when engines running. Conclusion....batteries and alternators are fine. This is verification by using a good handheld multimeter
2) When a large load(specifically the Captain Call switchable exhaust) on, the voltage reading on the helm, AND Garmin(via NMEA2000) shows that the Port voltage drops to around 12v. When the CC is off, the voltage is better...maybe 13v. Conclusion. For some reason, the NMEA AND voltage gauge on helm are NOT seeing the same voltage as the battery(which is at 14v when engines are running).
As stated earlier, I am not worried about the health of the battery and charging system...but.....why would the NMEA and the helm gauge show a low voltage? It cannot be the wiring to the helm because the NMEA does not use the same wiring(I assume).
I am looking for advice from any and all regarding how the NMEA and normal gauge is sensing voltage. Can someone let me know where the NMEA gets it's voltage? Then where the normal point of voltage sense for the helm would be? Trying to isolate why alternator and battery are fine...but the gauge for the port engine is showing low voltage.
Normally, I would not worry about the helm voltage...but as the NMEA voltage is low too....I have to believe that the engine is running off of the 12v(when Captain Call is engaged) This cannot be a good thing for the ECU and performance in general. There must be a bad connection somewhere...I am just looking for help in where to start looking.
Any help would be appreciated..
Thanks!!!
05-15-2017, 09:33 AM
#19
Registered
You could also run the main hot for 2 solenoids to the other batt, instead of putting all 4 on 1. And are you sure the NMEA isn't getting it's power at the helm where volts read lower?
05-15-2017, 09:36 AM
#20
Registered
Thread Starter
I assumer that the voltage does not come from the helm voltage source as the Garmin reports voltage for both engines. My assumption is that it comes via the NMEA network...but not sure.
