Battery Isolator Relay (solenoid)

[Rick Coleman]

My old solenoid recently went out (I think it was a Trombetta Fatboy) and the tech replaced it with an Intellitec Big Boy Battery Isolator Relay #77-90006-120. The first one lasted a week or two, and the second one has lasted just about as long. You can hear it click when powered up but the the 2 main contacts inside apparently are not joining. A lot of calls to Intellitec tech support (double hah hah) have been unsuccessful.

In many prior threads and discussions on this forum the last recommended solenoid was the Trombetta Fatboy 114-121-020. Is that still the case? emike feel free to jump in at this point! If that is the case what is the best source?

[Mike & Mike]

Rick,

Doing a Google search on the part number you provided, here's some info for you.

According to the Trombetta website (http://www.trombetta.com/distributor.cfm), one of their domestic distributors is down your way:

MurCal
41343 12th Street West
Palmdale, CA 93551
Phone:800-321-8386
Fax:661-947-7570
http://shopping. murcal.com/Trombetta
sales@murcal.com

The correct part number seems to be: 114-1211-020

You'll find this solenoid at webpage: http://shopping.murcal.com/Cat...-Family/114-1211-020 and it is called the Bear

I have purchased from Murcal before and they ship solenoids to me at work (Alaska) with no problem.

I'm not able to Google-up any Trombetta Fatboy solenoids!

The Trombetta corporate office is at (phone): 262.251.5454 (WI) and, if Murcal can't give you tech support, I bet Trombetta could.

Cheers!

[EngineerMike]

Mike's link to Murcal is a good one. It has a great photo of the Trombetta solenoid showing its top & bottom, high & low amp stud separation. The old Cole-Hersee (of which I carry two spares) had side mounted high amp studs and angled-towrd-front switch signal studs. The Intellitec Fat Boy has all top mounted studs with high bakelite separators to aid in not shorting out while wiring the gizmo.

Of all the options, I like the Trombetta best on both fronts- cost & design. It's $30 plus shipping at Murcal, its lower-front signal studs are easy to use (that top-rear stud on the Intellitec is a pain in the rump), and it has a two-piece case that splits at the bottom which should minimize water intrusion vs. top-riveted cases.

If your solenoid is dying out too soon, listen to see if it is snapping on/off/on/off all the time. They go fast when that's their status. That happens when the charging voltage isn't high enough and the sum-charge-of-both-banks is well down. First, battery charge (& therefore volts) is down; you plug in to shore & charge kicks on to house bank only (solenoid not on); house reaches sufficient volts to kick on solenoid. If the charger isn't set to put out enough voltage, and chassis + house charge load is high, a big charging amp draw will draw voltage down farther than the solenoid volt trigger so solenoid snaps back off. Volts go up (lower charge load without chassis) and solenoid snaps on; load goes up & volts go down, solenoid snaps off, etc., etc. I killed my Trombetta recently. Found the setting for the RS2000 charger wasn't adequate to overcome high total charging req'mts. The RS2000 needs to be set for max "Power Share" or it won't allow high charge rate from the charger side regardless, and then the battery bank Amp Hour rating needs to be set high enough to allow 65 or more amps charge. Mine was set (i.e. WRV'ed) to the actual house battery bank specs as "recommended." But I think the error is that once the solenoid kicks on, your actual AH's now include two Group 31 starting batteries (AHA!!!! or should that be DUH!!!!) so the setting req'd to charge the two banks is higher. I just eyeballed the setting up 5 amps at a time till I got >85amps charging (on downer batt's) and now everything is jakey, including the solenoid stays on solid rather than self destructing.

I've been thinking of setting this story in couplets of iambic tetrameter, and calling it To a Solenoid Dying Young where the moral to the poem is:
<span class="ev_code_BLUE">In the End, We All Get WRV'ed</span>.

[Rick Coleman]

Thank you Mike & Mike and emike.

[Oregon Coyote]

Ted: Can you explain to me in English what the h... Mike just said? Coupled iambic tetrameters give me a headache just thinking about them.

Norm

[bigfish]

May want to check the make/break amp rating and duty cycle (continuous or intermittent) for these solenoids. Intermittent duty solenoids may have a rating of 10 sec on/20 or 30 minutes off. With a duty cycle rating like this and a short cycling operation like EMike describes, solenoid will fail pretty quick.
BTF
05 40FDQS

[Ed & Diane]

Our solenoid is shot. It is the original WRV installed solenoid, a Trombetti Bear, (12V/Cont. 225Amp) Is this a good one to stick with for our 07 Apex?

We replaced our alternator a month ago. We replaced our inverter 2 weeks ago, I will start a new thread on that issue.

Ed

[EngineerMike]

That's the one I'd use, and I'd order a spare from MurCal (see above) to carry on the road. Good luck getting the original off the metal backboard. If it is like ours, the screws have nuts on the back side that will spin. I backed the screws out enough to move the solenoid side to side and get it off the backboard, then drilled new holes slightly above the OEM screws for mounting the new solenoid. Now I have screws that come out when turned.

[cajunjohn]

May sound stupid, but how do i kow if my solenoid is in good shape or not? Mine is OEM on a '99! What a bewildering thing is a MH!
Thanks in advance for helping me!
jt

[EngineerMike]

Here is a link to a previous thread on Charging Solenoid Test:
http://www.irv2.com/forums/showthrea...=solenoid+test

[Basil Shannon]

I went out to get a part number off my Trombetta to give to another owner and I notice it is quite hot to the touch which I assume is caused by contact resistance. Normal? I have had this one since about January 08 I think. I should probably order a spare.

[dgerstel]

Basil,

The solenoids do normally run hot, just heat from the coil being on most of the time. An easy test, is to check the voltage across the two large battery connections while the solenoid is engaged. The voltage should be 0, though not likely. Anything under .5 or so should be OK, the smaller the better. If you order a new Trombetta, make sure that the next to last digit in the part number is a 2 not a 1. The one is for copper contacts. Some friends had one installed at Guaranty, it had a 1 as the second to last digit in the number and failed in less than 6 months.

See here: http://www.trombetta.com/cm/pdfs/bear-family.pdf

[Old Scout]

Cajunjohn, WRV significantly changed the way they "wired" our coaches after 2004. Before 2004, the fatboy solenoid was used infrequently to boost house/chassis bat. After 2004, solenoids are in "continuous" use within the system. The solenoid in yr 99 probably hasnt been used much.

[Ted III]

Norm, once I got to the word "jakey" I was in trouble. It was close to 4PM when E Mike wrote this. Is that before or after siesta time? Or possibly cocktail hour.

Mike, I think possibly it might be more apropos if you were to put it to song.