House Batteries Not Charging When Driving

autostaretx

Erratic Member
The 3 connector units tend to use their metal frame as the "ground" ... so it has to be electrically connected to the Sprinter's metal.
Not much current goes through it, so the wire does not have to be beefy.
It only drives the relay's coil, so at most 2 amps.

--dick
 

lrcasella

Member
MyGplante - do not buy the 85 amp version. No better than the original Trombetta -copper contacts and low rating. Get the 24213. As far as connections, yes the 24213 has two connections for the coil. The second post must be grounded. The easiest (and best way to do that) is to just move the white wires that are connected to the mounting bolt for the Trombetta to the second small post on the Cole Hersee.
 

billbo

Member
MyGplante,

You should be happy, you got the same answers here as I gave you two days ago on the "other" forum as Kayaknn. So...get the danged 200 amp Cole Hersee and install it. There are two more forums you can ask but we all are gonna give you the same answer and how to connect the extra small wire, how to test it and again..none of us are misleading you or giving bad info. Have a nice day and good luck!
 

showkey

Well-known member
Another data point on low house battery charge while driving.
Recent trip noticed house batteries were charging very slowly.
In my RV house battery isolation relay is under the drivers seat. Removed seat measured voltage drop access the relay at .8 to 1.1 volt drop.

Relay was the Trombetta 684-1251-012

Installed Cole Hersey relay from Amazon for $42.79

Measured voltage drop at 15mv. On the new relay, measured under similar conditions.
Measured voltage at house batteries 14.0 volts.

Autopsy of Trombetta corrosion at the contacts. This a sealed relay, note gasket in the pictures and under the seat.

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autostaretx

Erratic Member
Thanks for the photos ... i believe the theory is that the contact disk will randomly rotate (due to road vibration, whatever) to distribute the contact burns around the entire surface.

Great theory.

But, that said, you can see that some rotation did occur.

--dick (why "mercury wetted" relays are popular in industrial applications)
 

Cheyenne

UK 2004 T1N 313CDi
Any theory as to how a 'sealed' device has corrosion inside????
I would guess moisture ingress through the cork gasket!

IMO it is the wrong material for the job. I believe cork needs to be kept 'wet' to ensure it seals, think of old fashioned petrol reserve taps drying out if not used then leaking!

Keith.
 

Alphacarina

2006 Itasca Navion 23H
My Trombetta looked brand new, inside and out (I took it apart) - The copper disk looked like it had maybe only made contact a dozen tomes or less - No pitting. The coil had failed. They look like an ordinary starter solenoid to me, but they 'say' they're rated for 'continuous duty' . . . . for the few hours they seem to last anyway. I pity those who take it out and source a replacement using the Trombetta part number they find on it - I think they probably gave Winnebago and several other manufacturers a hundred thousand of these useless things for free, knowing they'd make millions selling replacements!! :bash:

Don
 

showkey

Well-known member
How did moisture get under driver's seat? I wonder if that relay had moisture in it from the get go.
Damp air from the get go might have merit.

The cork gasket is a cork rubber mix.

The under seat area has always been dry. There are 10 other standard lighting relays, fuse box and wiring clusters all showing no corrosion or moisture.
These same relay/solenoids are used in RV, snow plow hydraulics and dozens of other applications.
Trombetta spec sheet confirms sealed units certified IP66 and IP67.

IP66 Enclosures. Able to protect against powerful water jets
IP67 Enclsoures. Able to protect against Immersion up to 1 m

Add some more picture........for conversation. Back cover has a fair amount of rust while the steel near by has none.

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hoosierrun

Active member
At least on a Trombetta you can clean the contacts for a short term emergency. A Dremmel tool with the small cup type wire brush might work good. In the end, that was a good find and replacing that relay will make your life be happier. lol.

On my RV, the chassis to house contactor relay was a White Rodgers and it lasted 1 year. The contacts were pitted and grayed. They may be rated continuous duty, but the make/break number cycles is apparently limited. I replaced it with a Cole Hersee and got 2 years out of it before putting in a waterproof Sterling B2B. Your pictures really tell the story of a bad failure there.
 

mrwallysprinter

2005 T1N 2500 158"
I replaced the Cole Hersee 24213 relay on my 2008 Navion IQ in 2004 and it fixed the problem of not charging the house battery while driving. Now I notice I have another problem which may be related to my fix and I'm not sure if I caused this problem with my "fix" 5 years ago. The problem is the AUX Battery on-off switch does not function so I installed a Harbor Freight cut off switch on the NEG post to disconnect the house battery while the RV was not in use. I am wondering if perhaps I connected one the the wires to the Cole Hersee relay incorrectly? The Battery Boost switch works and the house battery charges fine since I replaced the relay 5 years ago.
 

autostaretx

Erratic Member
Could you provide a wiring diagram? (at least what you think you've got)

I don't see how connecting a switch in the negative battery cable would affect the Cole Hersee (unless you took the whole mess apart during the neg switch install).

--dick
 

Alphacarina

2006 Itasca Navion 23H
Don't know about your particular year, but on my 2006, the AUX start battery solenoid is a different, heavier duty solenoid than the one which charges the batteries while you're driving

Don
 

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