Yet another solenoid bites the dust!

John_Canfield · 06-02-2008, 04:03 PM

We have now had our second or third failure of the battery bank bridging solenoid. This is the solenoid that energizes when you are running the engine to charge both battery banks, and energizes when you operate the "Battery Boost" switch.

I don't know why we have had so many failures, but I am about ready to yank it out and install a diode isolator (no moving parts!)

The disadvantage of the isolator is no more battery boost switch (unless I add that back in) and the diodes have a 1.2 volt voltage across them which will be manifested as heat (if 50 amps are passing through one diode to charge a bank, you have 60 watts that need to be dissipated.)

John_Canfield · 06-02-2008, 04:03 PM

We have now had our second or third failure of the battery bank bridging solenoid. This is the solenoid that energizes when you are running the engine to charge both battery banks, and energizes when you operate the "Battery Boost" switch.

I don't know why we have had so many failures, but I am about ready to yank it out and install a diode isolator (no moving parts!)

The disadvantage of the isolator is no more battery boost switch (unless I add that back in) and the diodes have a 1.2 volt voltage across them which will be manifested as heat (if 50 amps are passing through one diode to charge a bank, you have 60 watts that need to be dissipated.)

Mutha · 06-02-2008, 04:31 PM

John, a continuous duty solenoid should solve your problem. Here is a link to a very good heavy duty one:

Heavy Duty Solenoid

Good luck - Glenn

Harry B · 06-02-2008, 05:48 PM

Sorry to hear about your charging problem again John. I remember when you, mentioned it the last time that you had the same problem.

You might try changing it out for a Blue Sea Systems component. Being I used to be in their neighborhood in Seattle I have used their products before on my boats. They have a very good reputation.

It seems to me that continuing with the same part replacement makes no sense. You might compare the specs and see if this would work.

bluesea.com/category/2/productline/overview/389

I guess I have been fortunate to not have had this problem yet again. I did have the same problem on my previous coach. I have since carried a spare relay but have had no failures since (knock on wood).

MrTransistor · 06-02-2008, 07:37 PM

Hi John,

I mentioned in earlier thread that I have talked with the Trombetta engineers about this problem. To date, I have had no response and as far as I know they have not re-designed the part to solve the problem.

The contactor that they sell to Winnebago is designed as a strictly 12 Volt continuous duty unit and when operated in a coach winds up with 13.8 to 14.4 volts across the coil the whole time the engine is running. This causes it to draw too much current and severely overheat.

I replaced one contactor, overhauled it, and now keep it as a spare. By adding a 2 or 2.5 ohm 25 Watt resistor in series with the coil, the problem is solved. This allows the contactor to pull in at about 8 Volts yet keeps the power dissipation well within reason.

If you would care to do it, it's not too difficult to drill out the rivets, open it up and replace the rivets with screws when your done. That's assuming that the coil isn't too burned to salvage. All I had to do was clean the contacts.

I am including the part numbers for both the standard copper contact and much better silver contact parts. The resistor can be found at any good electronics store or even some Radio Shacks. I used a terminal block to connect the resistor.

The other option is as mentioned by Glenn and Harry. Replace the Trombetta unit with something else. I wouldn't go the battery splitter route since it supplies a reduced voltage to the batteries for charging, needs to handle the 150 Amp. alternator of the Diesel engine, and as you said, you loose the battery boost feature. Good luck.

Trombetta 262-251-5454
Tie Contactor
Copper contacts 114-1211-010-03 (Winnie PN)
Silver contacts 114-1200-020 (Trombetta PN)

Harry B · 06-02-2008, 09:28 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I mentioned in earlier thread that I have talked with the Trombetta engineers about this problem. To date, I have had no response and as far as I know they have not re-designed the part to solve the problem. </div></BLOCKQUOTE>

Looking at the Trombetta site it appears that they now also make a 15 volt version of this relay. The 15 volt version has a pull-in voltage of 9.5 and a hold voltage of 4.0 versus 7.5 volt pull-in and a hold voltage of 3.5 volts on the on the 12 volt version. All other specs are the same. It looks like they may have paid attention to your input Mark.

For myself, I would still opt for the Blue Sea Systems 9112 relay should my relay need replacing. The cost is about $180.00 however the 9112 relay is a sealed unit and pulses the relay coil instead of a continuously applied voltage. This should have less heat dissipation and it has all the needed logic internal for remote starting and dual battery sensing which pretty much eliminates the need for an Echo Charger or Trik-L-Start charger.

PeteB · 06-03-2008, 03:09 AM

John,
Just curious as I have not had any problems to-date. What were your symptoms that indicated that your relay had "gone south" and where is the relay located on your rig?

Thnaks,
Pete

John_Canfield · 06-03-2008, 05:51 AM

Pete - our head's up about the solenoid failing was the generator starting thanks to the auto gen start I installed. It started on a low house battery voltage. When the genny started, I looked at the Xantrex control panel and it told me it started on low battery.

I looked at the house battery voltage and it was 12.x and I knew that wasn't right.

Harry & Mark - thanks!! I have used Blue Sea parts on my boat and I was in fact looking for a marine parts solution for the problem.

Isn't that interesting that Trombetta has apparently responded to the high failure rate with this application of their product. I have partially dissected a previously failed solenoid, but stopped before I completely got it apart. I sent it to Bryan at Winnebago over a year ago so they could pass it on to Trombetta (or whatever.)

Lots of good information to chew on - maybe the simplest solution is to simply add the resistor.

Thanks everybody for responding

Harry B · 06-03-2008, 06:30 AM

Let us know how the final resolution to the problem works out John. I fully expect to see this problem at some point as well.

There are many problems re-occurring due to poor design or implementation. I have already headed off several problems due to others experiencing them first and sharing that info. When I inspect some of these issues, I can see quickly that for many it would be just a matter of time before failure.

That being said and based on some of my personal experience, I still believe Winnebago does a better job than most building and assembling RVs. There is however also much room for improvement yet.

By the way where is the relay located? Is it in the electrical compartment underneath the drivers seat? Or is it located in the rear electrical bay on the driver side?

skigramp · 06-03-2008, 08:47 AM

Piggybacking onto Harry's question ...

a) Is this the same relay that you hear click when you depress the MOM switch?

b) How large is it? (smaller than a can of soup?)

c) How many wires are connected to it?

d) What kind of markings are on it?

As you can probably tell, my relay has not failed ... and I don't have the slightest idea of what I am looking for ...

Thanks in advance John for educating me ...

Bob&Pat · 06-03-2008, 10:39 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by John_Canfield:
We have now had our second or third failure of the battery bank bridging solenoid. This is the solenoid that energizes when you are running the engine to charge both battery banks, and energizes when you operate the "Battery Boost" switch. </div></BLOCKQUOTE>

The first time I needed to use the "Battery Boost" switch it did not work, that was this past March in Florida. The funny thing was a neighbor commented as I was trying to start the engine "I bet your Battery Boost switch did not work." His Battery Boost switch failed when he tried to use his on his Winnebago.

I just got out the jumper cables and jumped the house battery to the engine and it started right up and charged with the engine very quickly.

We were using the slide-outs without starting the engine first and the chassis battery went dead.

MrTransistor · 06-03-2008, 11:35 AM

Hi John and Harry et al.

Thanks Harry for letting me know about the re-design. I'm finding a Powerseal part number 684-1551-012 that has the 15 Volt coil that would work fine except for the contact arrangement. This may or may not be a problem. It could be that other coach manufacturers use this device and that is why they redesigned it. Hopefully the one for the Winnies will get the same treatment.

The contactor that is installed in the Winnebago's is the ˜Bear' and there is a misprint in their .PDF showing a 12 Volt continuous duty unit that has a listed pull in voltage of 14 Volts. This is actually a 24 Volt device (you can tell by the coil resistance). I can see no change to the 12 Volt continuous duty contactor, so the problem would persist and the only answer for now is to add the resistor.

As I recall, the Trombetta part was around $40.00.

John,

The inexpensive way would of course be to repair the one you have and add the resistor. If you buy direct from Trombetta, you could try the 15 Volt Powerseal with silver contacts. Let us know how it fits if you go that route. $180.00 seems a bit steep for an alternative. You could buy a couple of 4G SD cards with the money you'd save.

Pete,

Who's contactor fails or not would be directly related to how much the engine is run and for how long. Many 8 to 10 hour driving days would be the worst since there is time for the heat and temperature to build up inside the contactor housing. Mostly little short trips would be the easiest on the contactor not allowing the time for the heat to build.

I think the normal mode of failure is pitted contacts due probably to the coil overheating and not providing enough pull-in force to keep the contacts cleaned. This would also support the argument for silver contacts, as well as a reduction in heat. If you hear the contactor pulling in or clicking but you don't see the voltage on the coach battery increase when you do, then it's the contacts that are pitted.

I thought about rewinding the coil with one gauge smaller wire and increasing the length of wire to increase the resistance yet provide the same magnetism as the original. But it turns out that just the resistor was sufficient to reduce the voltage and current and still provide a good solid activation of the armature.

The contactor on a Vectra and Horizon is located in the electrical compartment at the rear of the coach where the inverter is normally placed. It's behind a black painted L shaped panel above the inverter, held in with at least a half dozen screws and may have three circuit breakers and a 120 Volt outlet for the engine heater mounted on it. I believe this is the same setup on the Journey and Meridian. For the gas models, (which I haven't owned since 2001) I think everything is reversed, i.e. the contactors are in the front and the generator is in the rear.

SkiGramp,

a) Yes
b) Just about the same size and weighs 1.8 Lbs. Also has a metal bracket around it for mounting.
c) Normally 6, a 00 or 000 wire to the coach batteries, a 00 or 000 wire to the chassis batteries , a 0 wire connecting the two contactors together (the other contactor is the battery disconnect), a #1 (too small in almost all units) that feeds the front circuit breaker compartment and generator starter, and two #14 wires, a white and a yellow that feed the coil of the contactor.
d) A sticker with the Trombetta P.N. 114-1211-010-03 12V/cont (and other info)

Enough for now, have to take my son to PT. Go ride that Bonneville!

vicsryd · 06-03-2008, 04:03 PM

My MOM/bridge relay failed within a couple of months of purchasing the coach. A tech at Russ Dean RV in Pasco said he replaced it with a Bosch unit. I've never have had a problem since. Next time I have a chance I'll track down the extact part number.

rnabors · 06-03-2008, 07:17 PM

Hello John. I had the same problem and the last time I replaced the Trombetta solenoid I mounted a 12v 3" computer cooling fan in front of the unit. Knock on wood I have not had any additional problems.

tderonne · 06-04-2008, 04:30 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MrTransistor:
....I'm finding a Powerseal part number 684-1551-012 that has the 15 Volt coil that would work fine except for the contact arrangement. ...
... If you buy direct from Trombetta, you could try the 15 Volt Powerseal with silver contacts. ... </div></BLOCKQUOTE>

I'm not quite following. Does the part number you mention have the silver contacts? Or is that a different piece?

Mine hasn't worked reliably in years. My mom's in her '99 is failing too. We both frequently drive 24 hours straight engine running for whole tankfulls at a time, must be the long engine on time that kill it. I can easily add a resistor to something, but need to know the best starting point. (I'm assuming both mine and hers are junk, we've been living with hitting the boost switch a few times when the engine is one to get it to charge the house batteries.)

MrTransistor · 06-04-2008, 10:18 AM

Hi Tim

I stand corrected; the Continuous Duty Powerseal in the 15 Volt version is not available with Silver contacts. At that point the options are to use the original Trombetta ˜Bear' PN 114-1211-010 or the ˜Bear' Silver contacts Trombetta PN 114-1211-050 (also -020 & -060). These part numbers are a little different than in the original response, Trombetta changed the numbering and contact arrangement. I don't know which Silver contact type would be more reliable but it seems as though the –050 moveable would provide the self-cleaning action that I am familiar with in relay contacts. Trombetta sales may provide an answer.

Unfortunately, this still leaves the solution of adding the resistor to the coil circuit or buying a rather expensive alternative. I'll do a little research to see if I can come up with some part numbers and prices.

Trombetta's phone number is 262-251-5454.

PeteB · 06-04-2008, 11:53 AM

Mr. T,

I have not had any issues yet but am considering being pro active and going the resistor route. Could you be descriptive in what the mod is for a non techie?
Thanks,
Pete

John_Canfield · 06-04-2008, 01:59 PM

Back on the air after an Internet famine

We are now in damp, chilly and overcast San Diego.

Lots of good discussion since the last time I was able to look at the thread.

I think Mark answered most of the questions... As far as a physical description of the solenoid, it's about the size of one of those little cans of soup (or maybe a little smaller.) There are two studs on the top for the contactor (maybe 1/4"?) and two smaller terminals for the coil near the bottom. On the Vectra/Horizon, the solenoid is the inboard one (the outboard solenoid is for the battery disconnect.)

Pete - Mark's mod is to add a resistor in series with one of the coil terminals. This effectively lowers the coil voltage since the added resistor will drop voltage. In other words, if you have 14 volts on the coil and then add an appropriately-sized resistor, you can have 2 volts dropped by the resistor and the remaining 12 volts will be on the coil. It is a simple series circuit and you just need to use Ohm's law to do the simple math.

If I was going to do this, I'd mount the resistor somewhere outside of the little solenoid compartment for cooling. Hook up the yellow (+) wire to one resistor leg, connect a wire from the other resistor leg to the coil terminal. I forgot what resistor value (watts/ohms) Mark specified, but it is a few posts up.

Winnebago says they *have* worked with Trombetta and the solenoid used is appropriate for the application. I certainly don't doubt that since I know Winnebago is careful with their design and engineering, but that doesn't explain all of my solenoid failures.

My electrical bay is now forced-air ventilated and I was waiting to report on the performance of my mod. Results so far are really good and I haven't seen the bay get above about 100 degrees - in that case, only two or three degrees above ambient temps. I'm waiting to see how it does with a long travel day in hot weather. Since we left our place, we haven't done more than about five hours in a day.

This ventilation will doubtless help the solenoid live longer if Mark's diagnosis is correct.

smith88 · 06-04-2008, 02:36 PM

John I don't know what failed in your solenoid. I am on my third one and every one has failed because of oxide on the contacts. I have never had a coil failure. I took two of the solenoids apart and found the contacts were in excellent condition but had a film on the contacts. The third one in my Journey acts up from time to time. I can burn the oxide off the contacts by toggling the aux switch on the dash real fast as I am craking the engine. This draws current through the contacts and burns the oxide off. The solenoid then works for a while and then I have to repeat the trick.

Monte

Harry B · 06-04-2008, 04:45 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">My electrical bay is now forced-air ventilated and I was waiting to report on the performance of my mod. Results so far are really good and I haven't seen the bay get above about 100 degrees - </div></BLOCKQUOTE>

John,

I believe you probably solved several problems by power venting the electrical compartment.

As we know, excessive heat is major problem when it comes to electrical and specially electronic components as it changes the resistance.

It seems several things have problems in that compartment and if the temperatures run up as high as you have measured, it could explain the contactor problems as well as the inverter/converter problems.

I am on my 3rd dimensions 2000 inverter/converter and have had lengthy discussions with Dimensions' engineers regarding the failure rates I and many others are experiencing with their brand inverters/converters. They insist that it is a problem unique to the Winnie diesel pushers and have by their saying not determined as to why this is happening. At RV shows I have seen many other make coaches that have a factory installed exhaust fan present in the compartment where the inverter/converter is housed. As good as I was able to determine, those exhaust fans seemed to run anytime the inverter/converter was powered up or might have been thermal switched. I will also be installing a fan before we hit the road and for safe measure replace that contactor as well. Thanks for the tip on the temperatures inside that compartment.