Does anyone know if......

[Dick1142]

Does anyone know if there is a fuse to the battery isolator relay delay module or the isolator defeat relay? These are found (probably among others) in 05 Monaco products.

thanks for your help.

[Robi.1014]

Dick,

Your tomato ("battery isolator relay") was my tomaaaato ("battery boost solenoid" .... a phrase I used in a similar Owners-Forum post WRT charging while driving). Your description is better because that's the name of the product as sold by the manufacturers.

I'm 99% sure there is no fuse within the battery isolator relay (BIR), but you didn't ask that! Can't say about the BIR "delay module" or the "isolator defeat relay". My '04 Dip has a fuse upstream of the BIR (i.e., between the battery and one of the small terminals on the BIR).

In terms of troubleshooting your not-charging-while-driving problem, help us out with another observation as to what is (or is not) working) on your coach: Tell us if the "battery boost" function (as controlled by the switch at your dash) is observed to be functional. If the BIR does indeed shunt the house and chassis batteries when starting, then most of your BIR wiring and modules are functional. Each tidbit of information helps!

[Pusherpilot]

On our 04 Imperial the battery isolator (salesman switch) relay has a fuse built in to the relay. It is in line with the relay coil and when it blows the relay will not operate.
Ron

[Robi.1014]

Ron,

You've hit upon the reason why I like to use the description "battery boost solenoid" rather than use the "isolation" word. This solenoid is a different animal than the relay triggered by the "salesman switch" (which kills house-power to the coach). "Isolator" is a good name for this "salesman" device, for indeed, that's what the relay does. And yes: it has fuse(s) integrated into it. Us propeller heads would rather call this device what it really is: a "latching relay". When you give it a shot of juice (12VDC from the salesman switch), the relay shifts from one state to the other AND STAYS THERE when the juice is removed (taking your finger off the salesman switch). Neat device.

The solenoid that Dick and I are blogging about doesn't really "isolate" two battery banks. The banks are isolated by design from the git-go....for good reason. The solenoid, when energized, actually joins the two banks temporarily. Remove the solenoid activation current, and the banks are no longer joined (shunted together). No latching going on here.

[Dick1142]

ISSUE: House batteries do not charge when the engine is running.

This is what I have found so far:
1-the system IS supposed to charge the house battery when the engine is running (after a short (?) delay).
2-My battery selenoid is working. It wasn't at first, but I took it apart, cleaned it out, and polished the contacts. I can tell it is working when I hit the battery boost button. When I do, I can observe the voltage change on the dash and chassis volt meters.
3-During my "quest", I also found two bad house batteries. They showed 6 volts each, but no amps. I don't understand that, but....
4-Next, I found a bad battery master switch (cutoff) on the house side. Replaced it so it is not part of the initial problem.
5-In an effort to check the isolator defeat relay, I swapped some relays around, but it made no difference in any operation.
6-I have not found a way to test the battery isolator relay (a removable "board" in the circuit box beneath the drivers seat) short of buying a new one.

SOOOO, this is what I have done.
7-I installed a separate swich to manually power-up the battery selenoid (thru the boost circuit) via a new relay connected to the chassis power. That way, when the engine is running I can throw the switch and power the house batteries. If I forget to turn the switch off, it will automatically turn off when I shut down the engine.
8-I am also installing a new voltmeter on the dash so I can monitor the house batteries from the drivers seat. (ps...before I did this, I did check with the battery selenoid manufacturer (Trombetta) to confirm that the selenoid could be energized 100% of the time.)

So, I didn't find THE problem, but I did find a solution.

Dick Martin

[Denali]

Quote:

Originally Posted by Robi.1014 Dick, Your tomato ("battery isolator relay") was my tomaaaato ("battery boost solenoid" .... a phrase I used in a similar Owners-Forum post WRT charging while driving). Your description is better because that's the name of the product as sold by the manufacturers....

He is not talking about the battery boost solenoid. He is talking about the "Bi-Directional Isolator Relay Delay": http://www.intellitec.com/PDF/5300362.100.pdf. This is an Intellitec device that allows both the hose and chassis batteries to be charged from shore power, the generator, and the alternator.

[Denali]

Quote:

Originally Posted by Dick1142 ISSUE: House batteries do not charge when the engine is running... SOOOO, this is what I have done. 7-I installed a separate swich to manually power-up the battery selenoid (thru the boost circuit) via a new relay connected to the chassis power. That way, when the engine is running I can throw the switch and power the house batteries. If I forget to turn the switch off, it will automatically turn off when I shut down the engine. 8-I am also installing a new voltmeter on the dash so I can monitor the house batteries from the drivers seat. (ps...before I did this, I did check with the battery selenoid manufacturer (Trombetta) to confirm that the selenoid could be energized 100% of the time.) So, I didn't find THE problem, but I did find a solution. Dick Martin

I have the same problem, but only intermittently. Sometimes I can solve it by briefly hitting the Start Boost button. The Start Boost button will always link the batteries together in our coach, but sometimes hitting it momentarily will convince the BIRD-2 to keep them connected for charging while driving. Other times, not.

What I should do is simply replace the BIRD-2 to see if that fixes the problem. They only cost around $50: Bi-Directional Isolator Relay Delay - DIESEL [BR-31-0000839000] - $52.43 : MC Camping Supplies, Your Complete Camping Source

[DEG503]

On my 97 Exec, I had the problem of House batts not charging while driveing, for me it was the battery isolator (blue finned guy in engine electrical box) It was an easy fix once the smart guys on this forum helped me trouble shoot it.

David

[bullydogs1]

You might have the megatech board which tells the trombetta to close and thus charge the batteries.....If you have this board it is inside the front driver left run bay in the main fuse panel. I am replacing that board once the weather warms up with an updated one, meant to charge and close the relay with 13.6 v rather than 13.8...I don't know your coach but that megatech board was known to go hence the updated one.

[Sbrownstein]

The Boost solenoid or whatever you call it is perhaps the most problematic part of the RV DC system. When it works...all is well, when it doesn't nothing seems to work as the house runs down even after a 10 hour drive and the chassis runs down even after you have been running a genny or connected to shore power for days.

They fail since they spend an awful lot of time energized, getting hot and staying hot...wherever you finally find them. THis is the reason that virtually every RV parts store carries significant quantity and a bunch of different units.

I have found that the simplest way to verify that they are working is to always watch your dashboard volt meter or ammeter when you start the RV. Between 5 and 15 seconds after you start you should see a slight drop in voltage or a slight increase in amperage as the solenoid kicks in and by doing that you have easily confirmed that it is still working!

[Monacoach]

Should the board send a continuous signal to the isolator solenoid as in my case? I just got home from a second repair job. They replaced the board and the solenoid again. The problem was that the house batteries were not getting charged from the alternator. Now they are however there is continuous power at the solenoid from the board which I don't think is right. The techs were concerned about this but in the end they called someone who said this was normal. I think that as soon as the engine is shut down the power to the solenoid should be killed. Any thoughts?

[Monacoach]

After some research I have figured this out. Shutting the engine off does not instantly isolate battery banks. The isolator will separate batteries when voltage drops to 12.7.

[Sbrownstein]

You are absolutely correct. When the alternator stops the solenoid should drop out within a few minutes at most. Of course, I am assuming that the system is not plugged into shore power with the converter running. Depending on your BCC manufacturer, the situation that you describe is a known failure mechanism on at least the RV Custom products board and would indicate an ongoing problem with the board. If nothing is done, and the solenoid remains energized, the solenoid current by itself will eventually drain both battery banks down to nothing or even burn out the solenoid coil...again!

If the solenoid is always energized, without the engine or converter running, get somebody else to look at it...again!

[Dick1142]

If you don't care about it being "automatic", my fix I posted above works great. Have had no problems with it. Dick