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Regular Contributor
Not sure where to begin with this problem. I have two blowers, when they are on the voltage meter reads low (forgot the volts) but it is low. My instrument lights in the dash panel are low too, making it difficult to read them at night. This problem has been going on for a while and I figure it is time to solve it now. I seldom turn the blowers off because cruising down the intercoastal it is a "no wake" zone (Manatee season).

All four batteries are less than a year old (grp 27's) a 50 amp 3 bank charger (less than 18 months old) with two Yandina combiners. No problems here. I rewired the DC panel to the new house bank of two batteries a few months ago. So no all appliances and interior lights run through the house bank, in addition to radio and other electronics. Windless is also wired to the house bank and is seldom used. All battery wiring is new. I added a fifth battery and placed it in the stern next to the generator and is a standalone, not wired to anything except the generator via on-off switch. This generator wiring is not shown on my diagram.

The wiring changes were reviewed by Yandina and they say it is OK. A brief diagram is attached which only shows the battery setup.

Each engine has it's own battery, the cockpit panel is wired to the starboard battery as near as I can tell. This is where I believe the voltage drop is and before starting I thought to get some advice since I am very weak on electronically troubleshooting. The cockpit panel manages the nav lights and other lighting for the exterior, horn, blowers, actuators, etc. If the blowers are on, the horn does not get enough voltage to work, then I have to turn the blowers off and the horn works.

I was going to begin at the blowers and start tracing the wires. Instead of running around in circles, thought I would seek some advice.

Thanks to all.
 

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With blowers "on" have you checked for noise, heat, smell, etc to see if one or the other is "wearing" out?

If I were "king" I would start by using a meter and a good battery, (cutting in right at the blower and isolating each blower for the test), and checking each blower to see if one, or both has a defect which is causing an excessive draw on the battery.

If both blowers are running "normally" after the test.......then I would start up the "wiring chain".

I'm no expert with electronics either but as you said...you gotta start somewhere:eek:
 
I looked at the blowers and they seem to be OK, no excessive noise but as with blowers they are loud. No odors like burning, the wiring looks OK too, and one is fairly new, the other old.
 
The first thing I would do after checking or disconnecting the blowers, to see if the problem goes away, would be to find and thoroughly clean all of your system grounds, most of the time dim lighting comes from corroded or loose and dirty grounds. However, I'd be a little bit worried about running those blowers all the time, I don't think they were made for continuous use....Lee
 
Lee is correct...blowers are really not meant to be used continously...however...you will find a wide varience of opinion on when blowers should be used. Many do use their blowers all the time....some go by the 5 minutes on before start along with the "lift the lid and sniff" prior to engine start........I think a bit of common sense should rule.

I use the blowers for 5 minutes prior to engine start and after refueling. In my case I have two forward facing air scoops on each side of the boat, close to the engines, (total 4) that vent the engine room while underway. beside these, on each side there is a blower vent that faces aft and those two vents are connected to separate flex hoses that go down to the bottom of the engine room.

Personally I do not use the blowers in no wake zones.

If one is concerned about fumes and is always using their blower I would suggest a close inspection of the engine(s) and look for leaking carbs or poor fuel connections and poor lines and if all is well go by the 5min/sniff rule.

The other option is to purchase and install one of these...
http://www.iboats.com/Fireboy-Gasoline-Fume-Detector/dm/view_id.38734

Just my opinion.:cool:
 
I think you need to find out the rated amp draw for your blowers. It's not unusual for the bigger blowers to pull around 10 amps each. A 20 amp draw will pull the volts down especially at low engine RPMs,with low alternator output. Check the volts at the battery to get a true reading.
 
Thanks for the advice. I do not have a fume issue, a few months ago I added a two zone sniffer system and it works really well. One zone in the engine room and the other in the stern near the gas tank and generator. It will go off for high water, and several different types of fumes.

As for the blowers, I feel better running them in a low speed zone because I do not believe enough air is injected into the boat via the vents at slow speeds. Just trying to be safe.

I will begin by disconnecting the older blower to see what happens to the voltage. I tested the batteries last month when running and they all read the same voltage, forget now what that was but may have been 12.8 maybe a bit higher.
 
Have you checked what the altenator is putting out? I would start there and be sure that you don't have an issue with it. I would then check the ground wire to the panel and also the feed wire. If ether one is corroded then you are going to have issues.

How heavy is the wire feeding the panel? If it is to light then you not only won't get the power you need but could actually melt the wire. I would assume the same would go if the ground is to light.

You say that the batterys are new, there is always a chance that one could have a bad cell, you might want to have a load test done one each one. Or you could always run your panel off a different battery to see what happens.

As for the blowers, I would see what the manufactuer has to say, I think you will find that they are not built to run steady.

I just reread your last post, if while running all you are getting is 12.8 volts then that leads me to think altenator again. You should be getting more then that while running. What does each amp gauge show while running? I am just spit balling here, electrical issues are the pit's but if you can solve it yourself then you will come out of it a lot cheaper then hiring it done. Good luck and with the help from the guy's and gal's here you should have it solved in no time.
 
Last month I was tracing a different problem and checked the alternator and the voltage is good, that is when I also checked the batteries and they were good also, I was trying to get a steady sync gauge reading and to be sure the tachs were accurate as possible. The 12.85 voltage is the same on all four batteries with both engines running.

The dash dc panel is fed by 8 AWG, and I cleaned the negative bus bar some time ago, it is in a dry place so not corrosion problems there. All the connections in the dash panel have been cleaned and dielectric grease applied, last month. All in all the wiring so far has been found to be a good condition.

This week I will disconnect the older blower and check the voltage, and work from there. If this is a wiring problem it must be in the engine room, space is tight down there and not my favorite place. Thanks.
 
I was thinking more like the negative connections to your engine blocks and the batteries themselves and any other major ground connections that you know are in your system....Lee
 
Those were rewired over a year ago when I moved the neg cables to a bus bar, all batteries, engine, and bonding grounds are on the new bus bar.
 
If the instrument panel 'reacts' to a switch throw then somebody wired things based on ignorance or economy. The instrument panel really should be wired independently of the rest of the controls located at the helm...big reason is minimize the exact symptoms you are seeing.

The 'drop' is a real voltage drop and is due to the increased current draw when you close the switch feeding the blowers. If that switch is fed from a separate panel (assuming it has a separate set of cables to the battery), then there's an issue in a common ground wire OR there is a wire that is too small for the total current passing thru it (or a bad connector).

As far as starting, write down what you consider 'proper operation' and then see if what you have supports it...too small gauge wire is very common...especially if electronics have been added incrementally over the life of the boat.

A good digital meter will help the debug activity...an auto-ranging one makes life easy. As far as theory goes, Fluke has a tech note out for auto servicing that provides a good foundation for specific measurement techniques for this type of troubleshooting. if you can't find it, I could probably send out a PDF
 
I could not get to work on the boat today due to rain. As I thought this through, all my problems to date were switches. As suggested, it could be a undersized wire, possibly with the blower. I am going to access the dash panel, lower helm panel, and fuse panel and begin there. When I got the boat, the previous owner had added equipment with the positive wiring to the fuse panel, several are on the same circuit breaker, some time ago, I ran a positive wire from the battery (via fused accessory bus bar/block at the battery) to the helm, this was for future NK2 network with multiplexer. I may use this wire and add a new power bus bar in the helm for accessories.

Leo: The problem has always been there since I owned the boat. Not a huge problem in the past and can now be addressed. I have had many other priorities but as I work through them, the list is getting smaller. I have yet to begin on the engines, that is when this is going to get interesting. So far, the engines run great.

I have three digital meters, I like tools :cool: Mostly cheaper variety but the readings are always very close with all of them. All have auto ranging.
 
leokow said:
1.... and thoroughly clean all of your system grounds, most of the time dim lighting comes from corroded or loose and dirty grounds.

2.... However, I'd be a little bit worried about running those blowers all the time, I don't think they were made for continuous use....Lee
Click to expand...
1... Ditto!
Often we overlook system Negatives, and we tend to overlook harness connectors.

2... This may depend on the blower motors themselves. Some are continuous duty, intended to be operated when the engines are running.
Mine are continuous duty, and I run them continuously during engine run time.

FYI, the continuous duty are typically the squirrel cage type..... not the Turbo or In-Line style.
IMO, I'd avoid the In-Line style blower motors..... they are noisy and do not last very long.


makomark said:
If the instrument panel 'reacts' to a switch throw then somebody wired things based on ignorance or economy. The instrument panel really should be wired independently of the rest of the controls located at the helm... big reason is minimize the exact symptoms you are seeing.
Click to expand...
Ditto again!
The OEM hull harness is generally not rated for any much of an accessory load.
Add to this the Hull harness/Engine harness interface connections, a bit of corrosion, and we have a rather weak link in the system.

What I did with my twin continuous duty blowers, is that I fed them via a small five pin relay from a power source that is independant from the hull harness.
The relay is then triggered via the normal helm switch.
The triggering amperage is very low.... and your instruments won't even know it's there.
This removes the actual blower motor load from the OEM hull harness.

This is very simple to do using a 30 amp five pin relay....... about $4-6 to purchase one!

NOTE: this does not cure a poor Negative continuity issue, so you may still need to chase this down.
 

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I know what you mean about liking tools,probably could be said for most of the guys on this forum, I don't like borrowing tools,when I did the damn thing would break , I'd buy a new one for him and still not have one for myself, so I don't borrow at all. Sometimes the tool cost me more than the repair, but still less than taking it to a shop,so I guess things work out ok. It would be nice if when you disconnected the blowers the problem would stop,that would knock it down real quick for you. I checked mine yesterday and they are fused with 20 amp fuses and it looks to be about 12 ga. wire going to them. It may be printed right on your newer blower,that's where I found my info. I know it's not a big problem but it can sure be annoying, Good luck and have a Happy Thanksgiving.....Lee
 
Thanks Ricardo, a good suggestion too. I lean towards making sure everything is working correctly so what i want to do is to chase the voltage drop problem down first so I now what I am dealing with. I am going to rewire some of the electronics that came with the boat because they are connected to the same breaker as the blowers, I checked today. This was I will have a fused Blue Seas bus bar for the AP, and other equipment. My hope is this may solve the blower issue, in any case, this should be done because of a electronics upgrade planned for Jan/Feb.

The blowers are the same old type I have had in other boats:

PAR's now Jabsco:

{Continuous duty 100mm (4") blower, flexmount 12 volt dc}
 
bulletine said:
I am going to rewire some of the electronics that came with the boat because they are connected to the same breaker as the blowers, I checked today.
Click to expand...
Good call! :D
IMO this is where running a new/fresh dedicated circuit forward is a great idea.
Not only does this put your Nav and Electronics on their own independant circuit........, it keeps them from the OEM harness and from the main harness DC breaker that may trip or fail completely.


.
 
Good call on using those 5 pin relays. I have several on my boat to overcome one malady or another, and they work great. (You'd be amazed at the number of relays on the average car!) One particularly irksome problem--energizing the starter on one of my engines--was solved by using one of these relays to pull in the solenoid directly (instead of the usually circuit from the switch). For 5 years I battled this problem (there's an occasionally weak link in the circuit somewhere) before adding the relay that totally cured the problem.

Jeff
 
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