Another relay acting up...

[John How]

You may remember a couple months ago I my battery disconnect was not disconnecting. Turned out one of the I/O studs had been over tightened and was making contact all the time.
Now the other relay, the one that supplies 12v front the alternator to charge my house batteries is not connecting. With the engine running, I measure 14.4v on the right (alternator) side of the bottom relay and 12.7v on the left (house) side of that relay.
Now I am assuming that while the engine is running, that relay should be connected, am I right?
I also think that when my starter battery is dead or low, I should be able to use this relay to connect the house batteries as a boost to start the engine, right? It happens that the other day I was at a shopping center in the MH with the toad on back and left the lights on while shopping and when I tried to start after the batt was dead enough not to start. I tried the boost switch to no avail. Bought a battery charger on the spot and charged my battery using the generator.
Later, after driving for about 4 hours, we arrived at the CG to find that the house batteries were less than fully charged. They had been pretty full when we left home but had used some enroute, but I was surprised that the alternator had not recharged. Pretty much the same thing when I returned home.
Am I right in my assumptions, any good testing procedures you care to recommend?
Thanks!!!

[John How]

Forgot to mention, it is a 2006 Damon, Daybreak motorhome.

[dwhit]

My 1999 Daybreak 3270 has exactly the same relays you show.

Archival reading informed me that these relay contacts will become pitted and insulated and not perform properly. One contributor says to disassemble the offending relay and clean it up. Another suggests replacement. I had this same problem you have...I temporarily "fixed" by removing one of the relay trigger wires on the bottom relay while I was on my own shore power and repeatedly sparking the relay terminal with the wire causing the relay to make/break numerous times. This actually worked although it will be fixed better when I return home from my chilly trip to the Florida Keys.

These relays have a life span and are readily available.

The searchable archives on this forum will have instructions on how to properly test these relays for proper function. In my case the bottom relay was warm signifying actuation but as in your case 12.5vdc battery power was on the left terminal and shore-power 13.5vdc on the right signifying the internal relay contacts are pitted. I believe part numbers and suppliers were also supplied. All of it informative reading.

[John How]

I spent the morning taking measurements around the solenoid under different conditions, and I'm confused. I see house battery voltage on one side and chassis battery voltage on the other and that seems right when the solenoid is not engaged. There are 2 control pins on the solenoid and by my schematic, one should be connected to ground and the other comes from the ignition switch and aux start switch. With these wires connected, I see about 14v on each pin, slightly different from each other actually but close. The solenoid never does engage though. I took each of the control wires off and both still show about the same voltage though the schematic says one should be at ground potential. I went ahead and replaced the solenoid but this did not make any difference. It still acts the same.

Here is a pic of the circuit I have orate least close to my circuit. I cannot find the bock called "Bi-directional Isolator Relay Delay Controller" so I don't know of that exists in my circuit. Anybody have any idea about that. I don't really care if it is bidirectional or not. I just want my coach batteries to be charged while I am driving down the road and to be able too use the boost button when needed.
What has me puzzled is the lack of ground potential on either of the control pins. Also unclear is how the circuit decides when to allow charging of the batteries.
Thanks again for any assistance.

[teddyu]

John How,

Check you PMs. I sent you a PM on this subject. JM2¢...

[Old Bounder]

Here's a link to the trouble shooting procedures for you unit.

[John How]

Originally Posted by loulong

Here's a link to the trouble shooting procedures for you unit.

Thanks but unfortunately that doesn't look anything like what I have.

[dwhit]

I think John you have the older Intellitek unit. There's a lot of information on this unit in the archives.

I'm the type of person that will go in there for an afternoon and do thorough reading of numerous threads. I apologize if I'm exclusive in my enthusiasm to learn. Quick fix isn't my thing. I was educated as an engineer.

[TQ60]

Those are likely magnalatch

A pulse locks them via internal magnet then reverse polarity counters magnet and it releases.

These may be powered by coach battery so it needs to have enough charge to make it go.

If not hold down the boost switch then hit the control.

This is how a 1993 southwind works...yours may be different

[John How]

It's the bottom relay that is not closing. The top one is the house battery disconnect. All that does is disconnect the house loads from the house batteries.
The bottom relay is what connects the house and chassis batteries for charging and for start boost. One of the small pins on the relay(coil pins) needs 12v to close the relay while the other pin needs a connection to ground. I was not seeing a connection to ground on either pin and the wire that is supposed to supply that ground leads into the BCC circuit board enclosed behind the relays. Finally I pulled all that apart and found the circuit board. Sure enough, as you can see between the red and yellow fuses, there is a burned trace on the board. This is the ground buss. I will try to repair this board first. A new one is about $112 online if I'm unable to do that. I am unsure what might have caused this but I'll see if I can fix it.
It'll probably have to wait until after the football game though!

[Jim_HiTek]

A good repair technique would be to scrape off the conformal coating (that thin green layer on top of the copper traces), melt some solder on either side of the break in the trace, then lay a piece of copper wire (pre-tinned) across it. Then solder it in place.

Because of the nature of the problem, I'd be looking for a short somewhere before I powered it up. (Perhaps you already found it in post #1). A ground trace would never open circuit due to over current unless there is a short downstream from the fuse and the fuse is larger then specs.

Aside from that, the "Bi-directional Isolator Relay Delay Controller" is in there in that BCC (Battery Control Center). What it does, after the engine is started, is sense the charge on the chassis battery. When the voltage from the alternator reaches a certain level, indicating that the chassis battery is charged sufficiently, it closes that solenoid to allow charging of the house batteries. This prevents damaging the alternator and should give you fully charged house batteries when arriving at your destination. The amount of time it takes depends on the condition of the chassis battery, the size of the alternator, the cleanliness of all the interconnected connections, etc. It usually takes less then 2 minutes for the solenoid to close...with a new chassis battery, an appropriately sized alternator, clean connections, and an engine running at idle.

IF the chassis battery is old and weak, bad, or doesn't have sufficient water, or if the alternator is going bad, it may never come up to charge. So the relay will never close, and the house batteries will slowly be discharged while driving. After plugging into shore power, the CONVERTER will charge the house batteries.

[John How]

Originally Posted by Jim_HiTek

A good repair technique would be to scrape off the conformal coating (that thin green layer on top of the copper traces), melt some solder on either side of the break in the trace, then lay a piece of copper wire (pre-tinned) across it. Then solder it in place.

Because of the nature of the problem, I'd be looking for a short somewhere before I powered it up. (Perhaps you already found it in post #1). A ground trace would never open circuit due to over current unless there is a short downstream from the fuse and the fuse is larger then specs.

Aside from that, the "Bi-directional Isolator Relay Delay Controller" is in there in that BCC (Battery Control Center). What it does, after the engine is started, is sense the charge on the chassis battery. When the voltage from the alternator reaches a certain level, indicating that the chassis battery is charged sufficiently, it closes that solenoid to allow charging of the house batteries. This prevents damaging the alternator and should give you fully charged house batteries when arriving at your destination. The amount of time it takes depends on the condition of the chassis battery, the size of the alternator, the cleanliness of all the interconnected connections, etc. It usually takes less then 2 minutes for the solenoid to close...with a new chassis battery, an appropriately sized alternator, clean connections, and an engine running at idle.

IF the chassis battery is old and weak, bad, or doesn't have sufficient water, or if the alternator is going bad, it may never come up to charge. So the relay will never close, and the house batteries will slowly be discharged while driving. After plugging into shore power, the CONVERTER will charge the house batteries.

Well I was sitting here waiting for the game to start and I couldn't stand it so went down to the shop and fixed it. What I did is just what Jim is saying. Cleaned the traces and tinned them and then laid a small tinned copper wire on and soldered that in. An interesting thing though, the board can only go in one way in order for all the connections to line up with the openings in the case, the printed circuit board has the fuse values printed exactly in reverse of the printing on the case. A quality control issue for sure. I left them in the order they were already in which agrees with the case not the board. Anyway, it all works just like it's supposed to now. I get almost 2 tenths of a volt drop from the input of the isolation relay to the house battery, not too bad, they are about 8 feet away. WhenI get another person to help me, I'll check to make sure the start boost is working as well.
Thanks a bunch for your assistance guys!!!

[Old Bounder]

Sorry about the earlier link John. This should be more like your BCC. If it's not exact, let me know because I have them all.

[dwhit]

Good job John!

Now you know a LOT about the Intelletec BCC.

Interesting note on page 5 states to remove ground spade before disconnecting battery terminals. This may or may not be a result of previous activity by previous owners, etc...or something that occurred downline of the BCC.

Never a boring moment with MH accessories.

Electric issues are the most interesting.

Thanks LOULONG for supplying the schematic...I found it in the archives some time ago and it helped me with other issues.