Author Topic: Electrical Question  (Read 5876 times)

Mark Stewart

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Electrical Question
« on: December 08, 2016, 07:42:09 PM »
I fear this won't have a simple solution, but thought I'd give it at shot. New to me 1999 Patriot 330hp. Batteries were pretty much toast. Replaced with Trojans and 31 Group chassis batteries. Connections are clean and tight. Never any problem starting the coach or generator. Both run great. All 120 and 12v appliances, lights, etc...work good. However, as in so many posts here, brand new chassis batteries draining fast. Cat mechanic comes over, checks things out, determines alternator is fried, probably from trying its best to charge those previous dead coach batteries. Replaces it with new Leece-Neville Duvac. Okay?  Then this... when turning the key on, Silverleaf starts to boot, then quits. Two or three seconds, does it again, and again. Never a problem before new alternator. Cat will start, and continue to run, if holding the key to start position. But, it starts only when hitting one of these 2 or 3 second "electrical spike" occurrences when Silverleaf and gauges try to start. So, I assumed this may be caused by a faulty ignition solenoid. With the key in the on position, in the electrical bay, the solenoid was clicking on and off, every 2 to 3 seconds, as was the Allison ecu. Replaced the solenoid along with its diode. No change. Still clicks. Batteries well connected. All batteries reading 13.4 at bank and left buss bar in electrical bay. Delivers bursts of 12v current  to right buss bar as solenoid clicks on and off. Could the mechanic have shorted something when installing the new alternator?  This did not exist prior. I feel I may have a lot of wire tracing coming up, unless someone might have some ideas, or places to start. And from reading here, you guys are way out of my league when it comes to knowing stuff about these coaches. I do love mine, I just want all things working.
Thanks in advance!
Mark

Keith Moffett

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Re: Electrical Question
« Reply #1 on: December 08, 2016, 10:43:40 PM »
Mark
First off let me welcome you to the Beaver family.  The learning curve is steep and maintenance may have gotten over looked but once you get caught up it will be worth it.

Now that alternator is suspect.  The connections should be checked first because I believe the Silverleaf reads power right off the connector.  That is what I was told with our 98 Pat. 
If the connections are not reversed then get the alternator checked.  I bought a new one (not rebuilt) from Leese Neville and got junk.  I had it rebuilt in a shop and it was great.
I would hold off on alot of worries about wiring until you get more details here!
2007 Patriot Thunder
45' C-13
2006 Explorer Ltd.
DW is Carol
Safe travels and
May God bless!

Mark Stewart

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Re: Electrical Question
« Reply #2 on: December 08, 2016, 11:27:49 PM »
Thanks Keith,
I had the same idea that could be the problem. I'm certainly in no great hurry as she is basically put to bed for the winter. Just glad I'm not stranded out there somewhere. I was planning on getting the old alternator rebuilt for a spare anyway. Probably do that and stick it back on and see what happens. Learning curve is definitely steep. They are pretty complex coaches. But, man it's gonna be nice when everything is done.
Best,
Mark

Edward Buker

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Re: Electrical Question
« Reply #3 on: December 09, 2016, 01:08:57 AM »
Mark,

You should be able to isolate the alternator as a culprit by disconnecting the alternator wires and then taping them off. Turn on the key and see if you still get these intermittent connections that you consider "bursts of power/voltage". If the problem goes away with the alternator being disconnected then that is suspect. I would not start the engine unless the wires were reconnected so that there is a load on the alternator, like connected batteries.

If you do still have an issue, put a meter on the two small wires on the ignition solenoid and monitor the voltage. What is unknown is if the voltage that holds the solenoid on is intermittent or not. This problem could be that the contacts in the ignition switch are providing inadequate voltage and current to hold the ignition relay closed. If the ignition relay in the electrical bay has pulsing voltage on the small wires then check if the voltage coming into the ignition switch is pulsing also. If not it is likely the switch that is causing this issue. If it is pulsing there may be some other issue pulling current intermittently that pulls the voltage down low enough to cause the solenoid not to hold its contacts closed. You will have to trace and lift wires to see what the source is that is causing the problem. Hope this helps.

Later Ed

Mark Stewart

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Re: Electrical Question
« Reply #4 on: December 09, 2016, 01:27:30 AM »
Thanks Ed,
I read your words of wisdom often. Certainly have learned a lot by doing so. I will take your advice and check it out this weekend. Will holler back.
Best,
Mark

Mark Stewart

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Re: Electrical Question
« Reply #5 on: December 10, 2016, 10:50:19 PM »
Okay,
So, here's what I did today. I found the wire at the alternator that was causing the problem. It was the small wire connected to the ignition stud. When I removed it and turned the key to on, the Silverleaf booted correctly and read 12.7 volts... all other gauges also resumed normally. It was the only wire that had this cause and effect when disconnected from the alternator. If it is connected, things go all out of whack. Could the ignition wire and sense wire have been reversed when I had the alternator installed?
Thanks for any ideas,
Mark

Edward Buker

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Re: Electrical Question
« Reply #6 on: December 11, 2016, 05:27:23 AM »
Mark,

It would seem that ignition wire is pulling more current then it should and is causing a voltage drop that the other units like the Silverleaf are seeing and responding to. I do not think it is wired wrong (but not sure) in that the ignition circuit is acting like it has low voltage and that is the terminal you are connected to. Lift the ignition wire at the alternator and measure the voltage with the key on and off and see if it toggles the voltage. If so it is the right wire.

Then put the wire back on the alternator and measure the voltage with the ignition switch on, measure at the alternator ign. connection. Also measure voltage at the ignition buss (the one turned on by the solenoid at the bottom)in the electrical bay with and without that alternator ignition wire connected, with the ignition switch on.

It is hard to imagine that small wire at the distance of the alternator causing the kind of voltage drop that causes these symptoms. It may be that the alternator itself is pulling a lot of current when the ignition wire is connected to B+12V and it should not be. Basically you have to find out what is pulling so much current that it causes a low voltage condition or where is there a poor connection causing a low voltage condition causing these symptoms. These measurements should help. You may need to have the alternator tested to rule it out before this is resolved.

Later Ed

Mark Stewart

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Re: Electrical Question
« Reply #7 on: December 11, 2016, 02:15:25 PM »
Thanks Ed,
I'll check it out. Does seem odd that it would be the wire, since this issue never presented itself with the original alternator. The old alternator is headed to the shop to be tested and rebuilt. When it comes back, I think I'll stick it back on, see what happens, and move forward from there. Think I'll take a little break and quit worrying about it so much. We're not heading out until late spring and all else with the coach seems fine.Thanks again. I'll let you know how it turns out.
Merry Christmas to you and all here,
Mark
« Last Edit: December 11, 2016, 02:19:51 PM by Mark Stewart »

Mark Stewart

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Re: Electrical Question
« Reply #8 on: December 11, 2016, 02:27:59 PM »
One last thing... the sense wire should be hot all of the time since it comes from the isolator, right? The ignition wire only becomes hot when connected to the alternator with the key on. If true, at least I know it's hooked up correctly without tracing wires, I think.

Mark Stewart

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Re: Electrical Question
« Reply #9 on: December 11, 2016, 03:02:10 PM »
Or rather the ignition wire becomes hot with ignition on, hooked up or not to the alternator since it gets power from the buss bar.

Edward Buker

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Re: Electrical Question
« Reply #10 on: December 11, 2016, 03:31:06 PM »
Mark,

The ignition wire is hot with the ignition on, the sense wire is hot all the time. The sense wire is there because of the battery isolator. That unit has a voltage drop from the isolator diodes, and the Duvac version remotely senses the true battery voltage and compensates for the diode voltage drop. My guess is that something is wrong with that alternator. Getting the back up rebuilt and trying that is a good way to sort this out.

Regarding the ignition wire, I do not think that wire itself is the problem. There can be some inline resistance (like the solenoid contact, or the ignition switch contact) feeding the ignition circuit and when you power up the ignition wire and then add the load of the alternator ignition wire circuit, it drops the voltage enough to cause the low voltage symptoms. That is what we do not know, if the alternator itself is pulling abnormally high current or if the wiring circuit feeding it has a series resistance that is causing the problem. No need to rush on this, when you get the back up alternator that should answer the question, enjoy your Christmas.

Later Ed

« Last Edit: December 12, 2016, 03:17:57 PM by Edward Buker »

Mark Stewart

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Re: Electrical Question
« Reply #11 on: December 11, 2016, 04:10:45 PM »
Thanks Ed. You, too...