Part number Isalotor Relay

[Pedrodasdas]

Hello, finally found the problem why the batteries were not chanrging on engine.

The isolator clicks but the parts inside do not connect.

I need the part number of the isolator. NAPA or anywhere else.

Here is a picture of the isolator.

Thanks.

Leaving for south on Nov 2nd !

[bubbles]

There should be a part number and manufacturer printed on the unit somewhere.

[Slow_movin]

Check this website..your part MAY be on there....Products

[Pedrodasdas]

Found it:
This part number has now been discontinued and replaced with #24213.
24123 had silver contacts; the replacement 24213 has superior silver tungsten carbide contacts, but is electrically identical.
200A, with silver contacts. Normally Open Contacts, spst, One circuit: Off - On
Housing: Plated steel
Studs: Copper 5/16" -24 thread, hexnuts and lockwashers included. Coil, ignition and ground terminals: Steel 10-32 thread, hexnuts and lockwashers included.
Bracket mounting holes 5/16" x 19/32" (7.9 x 15.1) on 2 13/64" centers (56.0mm).



WARNING: Before you try to replace it, disconnect ALL batteries (frame and coach), not easy to unscrew the nuts.

[cousin01]

Any after effects from disconnecting the chassis battery?

Did you just pull the plug near the gas pedal and disconnect the house battery from its cables?

[Pedrodasdas]

Do what I say, don't say what I do !
I did not disconnect the chassis battery, I was afraid of the collateral effects !!!!
I just put electrical tape to avoid touching the negative.
You unmask me !

[cousin01]

Well I have been over at the sprinter forum researching procedures for disconnecting and reconnecting the chassis battery.

I did not find reference to any adverse affects except a possibility that the radio might have to be re authorized. Something about a code that has to be entered into the radio.

Just found the following info regarding the "battery master switch" located near the gas pedal.

http://www.lonestarsprinter.com/lone...ter_config.pdf

Details & Technology
The battery master switch breaks the ground connection between the the battery and the body and switches off all electrical consumers.
It is situated in the driver’s footwell, to the right of the accelerator pedal. The battery master switch is activated by disconnecting the
earth bolt connector.
It must be ensured that the battery master switch is only disconnected when the vehicle key in the ignition lock is in position 0,
otherwise there is a risk of damaging other components in the electrical system.
Benefits & Arguments
 Prevents uncontrolled discharging of the battery
 Work on the electrical system can be carried out more quickly
The battery master switch prevents uncontrolled discharging of the battery due to quiescent current consumption. It is recommended
for vehicles which are likely to be immobile for extended periods. The battery master switch also allows work on the electrical system to
be carried out more quickly, since it is not necessary to disconnect the battery pole.


this looks like the way to go if working on the ISO relay.

Am I missing anything?

[Slow_movin]

2011 Solera 24s
This procedure for battery disconnect is also explained in the Sprinter owner's manual. It works for me.

[Nats]

I'm getting ready to put my Solera up for the winter so I made sure I could disconnect both batteries. I installed a ground disconnect switch for the house batteries so I made sure they were disconnected from the frame, I then pulled the chassis disconnect by the gas pedal. Everything was then dead so I am pretty sure I can put it in storage and find the batteries in good condition next spring.

The only thing I did was insert the key and leave it at position 0 before I reconnected the chassis battery as instructed in the manual.

Everything came back up OK, I didn't even have to re-initialize the windows as identified in the manual.

[cousin01]

Good to know. Thanks for the first hand report.

[cousin01]

Ok, I just finished replacing the isolation relay.

A couple of observations.

Absolutely should disconnect both batteries before attempting this. The procedure in the MB owners manual is to be followed to disconnect chassis battery.

For the coach battery, disconnect ground, then positive.

Now safe to work on the relay.


From inside, remove the nuts on each side of the isolator relay. Disconnect red and white control wires.

Unscrew the screw on the control board marked " coach battery" This screw connects to one of the the mounting arms for the relay.


From underneath:

Disconnect the battery connections from the rear of the isolator panel.

Loosen the nuts that hold the battery studs to the rear of the isolator panel. Back them both off about an inch.



Remove 4 screws that hold the isolator panel in place.

Pull the isolator panel out far enough to get at the mounting nuts for the relay. Remove the nuts. There should now be enough play in the relay and the mounting arms to remove it.

Install the new relay. first LOOSELY attach the mounting arms. Next position the battery studs and snug them up. Note that there is a nylon bushing between the mounting arm and the isolator panel. be sure this is fit squarely in the hole. (Also make sure there is a nylon washer under the nut that secures the stud. If you didn't remove the battery studs, but simply loosend them, then the washer and bushing should still be there!)

This isolates the battery connection from the isolator panel which is grounded. Get this wrong and it will ruin your day.


I checked everything with an ohm-meter to ground to be sure the battery studs were reinstalled correctly.


You can now tighten the nuts holding the mounting arms to the relay.

Still working from beneath the coach replace the nuts that hold the relay in place.

Now re install the isolator panel using the four screws.

Reattach the battery cables to the rear of the isolator panel. Use two wrenches to be sure to get a tight battery connection while not over-tightening the mounting stud which could ruin the nylon part)



Inside the coach, reconnect the red and white control wires to the isolator relay.

Replace the screw on the control board for the "coach battery"


At this point I retested all of the battery connections with the ohm-meter to be sure they were still isolated from ground. Cant be too careful here.


Reconnect the coach battery positive cable, then the coach battery negative cable.

Finally, with the key in the ignition and in position 0 (per the manual) reconnect the chassis power cable near the gas pedal.

This took me about two hours but I had a couple of false starts before I got the sequence right. It should only take about 45 minutes.

this is a pretty simple repair but it will test your manual dexterity!

[Pedrodasdas]

Hello, nice post cousin01.
In my case, after I unscrew everything on the relay , I just bended the "wings" on each side of the relay to take it out.