Lots of discussion on merging of the house and engine batteries on other threads. I just changed my merge relay for a couple of reasons, it was old, hot and it had some internal resistance across the contacts producing a voltage drop. I think Newell recommends changing this relay every year. So I cut mine open to show why. It is a simple coil magnet plunger with contacts. The contacts were pitted and burned a little, the contact disc was the same.You never know when the next closing will either weld together the contacts, or the coil fail to pull down the plunger from heat damage. The part for mine was a Cole Hersee 24106 found easily on Amazon. It is very easy to change. But I recommend disconnecting shore power and batteries isolated first. A short to ground while energized will be same as a welder.
Terry & Cherie 95 Newell, 45', FMCA Show Coach, Series 60, Allison HT741 4spd, #373
The 24812 is a new product from CH and is rated continuous duty at 200 amperes with 12v coil. The large cables may not fit exactly but that is easily overcome with the benefit of the increased current. In the $100 range.
The one in the picture I don't know how old it was, I bought our coach in 2019, it had brand new house batteries, the start batteries I changed this Summer and after reading about the merge relay here, decided to investigate our merge system. In merge the bus voltage was different at the house batteries than the start batteries at the battery terminals. So I was working the charging system outwards, when the merge relay came to play. Realizing of course that length of wires, quality of grounds and battery condition that no coach will be perfect match as to voltages. There was a difference in voltage on either side of the merge relay. It needed to come out. The relay in the picture I cut open maybe circa 1995, I don't know. The outside and inside of the can metal reflects a lot of time even with our coach being stored indoors. I thought I'd post the pictures, might help others.
Terry & Cherie 95 Newell, 45', FMCA Show Coach, Series 60, Allison HT741 4spd, #373
Was the relay located in the aft engine bay compartment that is accessible from the rear of the coach (not the right side access)?
I ask because I tried to merge the house to engine batts and my annunciator light did not illuminate.
Kristi & Jeff King
Bentonville, Arkansas
#744 2005 45’ Newell Coach
ZF Suspension/Active Steering Tag Axle
CAT-13 ACERT KCB Engine 525HP 1642 ftlbs Torque Cat Compound Turbocharger 43.5 psi
Allison HD4000MH Transmission with PTO drive.
Was the relay located in the aft engine bay compartment that is accessible from the rear of the coach (not the right side access)?
I ask because I tried to merge the house to engine batts and my annunciator light did not illuminate.
[attachment=10420]
Kristi & Jeff King
Bentonville, Arkansas
#744 2005 45’ Newell Coach
ZF Suspension/Active Steering Tag Axle
CAT-13 ACERT KCB Engine 525HP 1642 ftlbs Torque Cat Compound Turbocharger 43.5 psi
Allison HD4000MH Transmission with PTO drive.
But a few seconds with a voltmeter will tell you if you have a light problem or a merge relay problem.
Measure voltage on both terminals to ground. They will likely be different. Record the numbers.
Now, take a jumper from either of the terminals to the small post in the center. That activates the relay.
Measure the voltages again. If they approach one another compared to the previous measurements, then the relay is working. If the voltages don’t move, you need a new relay.
I am suggesting this test, because the annunciator(pilots, what you gonna do with them?) light is powered by the switch up front, it just tells you if the switch is made or not. It does not tell you if the relay is working.
Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home )
The connector was pulled from the switch by the weight of the wire bundle and the manner it was twisted around behind the console. I’ll try to reposition it and tie it up to remove the tension. I’d rather not take everything apart more than I already have because this was NOT on my project list today.
I’m going to make a pigtail using connectors with plastic covers. This will protect things as I try to slip the new pigtail on the switch’s blade connector.
Wire bundle support strap.
It’s always something!
JK
Kristi & Jeff King
Bentonville, Arkansas
#744 2005 45’ Newell Coach
ZF Suspension/Active Steering Tag Axle
CAT-13 ACERT KCB Engine 525HP 1642 ftlbs Torque Cat Compound Turbocharger 43.5 psi
Allison HD4000MH Transmission with PTO drive.
(This post was last modified: 10-07-2022, 03:33 PM by jdkskyking.)
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