2003 Windsor Chassis Maintainer maybe NOT working? Hamsar Relay Swap? How to test and troubleshoot maintainer and/or relays?

[Russell]

2003 Monaco Windsor

I started a discussion on Facebook about some issues I have been having with the battery maintainer for the chassis batteries. I'm not getting much of a response, so I thought I'd post here. It was suggested that if my battery maintainer is functioning (green light on) that the issue could be the relay. (see pics) I have the green light. 

Chassis batteries are dying while plugged in to shore power. House batteries, I believed were maintained by the inverter, but it seems they too are topped-up with this battery maintainer located in the rear electrical bay. 

It appears to be the relay on the right which feeds the chassis batteries. What I'd like to know is how to test this relay. I found a pack of several here: https://www.amazon.com/5Pack-Replacement-irhapsody-Automotive-Starter/dp/B0BJ9S2MQ4/ref=sr_1_2?crid=41KIXQNY4Y2S&keywords=hamsar%2Brelay%2B42-032T%2B12V-40A&qid=1699997345&sprefix=hamsar%2Brelay%2B42-032t%2B12v-40a%2Caps%2C1148&sr=8-2&th=1

This makes sense to have a few extras being that these 2 relays seem to be identical. However, these may or may not be the right ones.

So another question is: How can I find an replacement part number? This "Hamsar" doesn't show up on Amazon. 
Furthermore, once I procure the correct relay, how will I know which wires go to which pins? The current relays have a little diagram on the top but I don't see that on the replacements. 

Thanks!

[Steve P]

@Russell Have you tried contacting Hamsar at hamsar.com or the number they list?  One would hope they can identify a cross-reference relay with the same functions.  

Some manufacturers emboss the relay info into the plastic housing, making it harder to see.

HD Switch 12V 40A Waterproof Relay Replaces Hustler 601053 026237 Super Z Super Mini Z ZR7 X-One Z4 Sport Super Fastrak Raptor Mini Fastrak Mowers w/LED & Dielectric Grease https://a.co/d/052CZaY

That one on Amazon appears to have the same diagram as yours.

 

[Tom Cherry]

41 minutes ago, Russell said:

2003 Monaco Windsor

I started a discussion on Facebook about some issues I have been having with the battery maintainer for the chassis batteries. I'm not getting much of a response, so I thought I'd post here. It was suggested that if my battery maintainer is functioning (green light on) that the issue could be the relay. (see pics) I have the green light. 

Chassis batteries are dying while plugged in to shore power. House batteries, I believed were maintained by the inverter, but it seems they too are topped-up with this battery maintainer located in the rear electrical bay. 

It appears to be the relay on the right which feeds the chassis batteries. What I'd like to know is how to test this relay. I found a pack of several here: https://www.amazon.com/5Pack-Replacement-irhapsody-Automotive-Starter/dp/B0BJ9S2MQ4/ref=sr_1_2?crid=41KIXQNY4Y2S&keywords=hamsar%2Brelay%2B42-032T%2B12V-40A&qid=1699997345&sprefix=hamsar%2Brelay%2B42-032t%2B12v-40a%2Caps%2C1148&sr=8-2&th=1

This makes sense to have a few extras being that these 2 relays seem to be identical. However, these may or may not be the right ones.

So another question is: How can I find an replacement part number? This "Hamsar" doesn't show up on Amazon. 
Furthermore, once I procure the correct relay, how will I know which wires go to which pins? The current relays have a little diagram on the top but I don't see that on the replacements. 

Thanks!

The relays are what is called a “Bosch 87/87A”.  Google that and look at the circuit diagrams.  There are many YouTube videos that explain how they work.  The relays are a Single Pole Double Throw (SPDT) relay.  Terminals 85 and 86 is the voltage to the coil.  The 12 V means that the relay coil must be used in a 12 VDC system.  Pin 30 is a common pin.  With NO relay coil voltage….and they are assumed to be Normally OPEN with No Voltage, Pin 30 and Pin 87A make a circuit.  But when voltage is applied to pins 85 and 86….and either one can be grounded….they are not polarity sensitive….  THEN. Energize (put voltage on the coil), the relay “closes”.  THEN, Pin 30 moves to pin 87.  Thus you have a circuit between Pins 30 and 87 and there is no “circuit” to Pin 87A.

BTW….there ARE some relays that do NOT have the Pin 87A….so they are a 4 pin relay and the 87/87A is 5 pin.

NOW….got all that…??. OK, the 40A means the contacts are rated for 40 Amps.  That means that you could use a piece of #8 wire.  The TYPICAL “Bosch 87/87A” relay comes in 25 or 30 amp ratings.  In your picture, the Red wire “appears”, guessing…to be #10… #10 is good for 30A. #8 is 40A and #12 is 20A.

Next up.  These relays are NOT in a socket.  That tells me, that the current is higher….so, the wiring was run directly via a solder-less or crimped terminal.  

MOST of the Bosch style relays we have are plugged into a socket.  But, when higher currents are needed….direct wiring is used. Finally…there ARE some Hamsars that have a different layout for the terminals….so that a Hamsar 87/87A will not fit or interchange with the more commonly used Bosch.  

OK….at this point….kidding of course, we have had folks say….SELLING IT TOO COMPLEX.  But in order to troubleshoot and test, you need to understand how the circuit works and what contacts are closed and where the control voltage comes from.

Pull your prints.  What energizes the coils? Also google and find a diagram for that relay.  MY GUESS….the relay on the Right…. The two outside terminals are the coils,  the white wire is probably Ground….and runs to both.  The right relay yellow  is getting a signal or voltage to the coil from a common circuit….maybe an Ignition ON. Your prints will show that.  The Left relay is getting a control circuit from some other circuit….and that may NOT be the “ignition on”.

Based on the wires….and a PURE GUESS….the right relay is NORMALLY OPEN.  The incoming RED should have gone to 30….  However, there is an unused terminal.  So only terminals 30 & 87 are used….the unused is probably 87A.  You need to look at the bottom of the relay.  The 30 pin will be in the middle of 3 pins.  The coil pins will be different or not in line.  That is why you need the prints as well as a diagram of the Hamsar “pin layout”.  If ONLY the 30 and 87 are used…..then, power into 87 will be connected to 30….so, you can, and Monaco OFTEN DID THIS, interchange 87 and 30 as they were merely ON/OFF circuit or switch.

Next up.  Notice that the front pin is used on this relay.  That, my suspicion would be is the 87A pin.  So, that relay MAKES a circuit when the coil is NOT energized.  Apply power to the small red on the left…..the relay is energized….and the circuit between 30 and 87A is shut off or turned off.

NOW…it, in your case, doesn’t matter if you install a Hamsar or any brand.  The terminals are hard wired.  i WOULD only purchase a 40A relay….and buy a NAME brand.  I only buy BOSCH relays….they MAY make a 40 A model.

Now, with this explanation….and doing some googling and watching the YOUTUBE videos and a VOM, you can trouble shoot the coils.  

OK…..this is what you will NOT, maybe learn.  If the contacts are “pitted” or corroded from constant closing snd opening.  You need to use your VOM on the terminals 30 to either 87 or 87A.  You MUST measure when the relay contacts (30 to whichever one is used…87 or 87A) is making a circuit.  UNDER LOAD….as in “working”.  You can measure and find the incoming 12 VDC.  But….you need to push the VOM leads into the BACK of the terminals 87/87A and the respective terminal 30.  Put the VOM on VOLTAGE.  If you read a voltage of say more than 0.1-0.2…..BAD CONTACTS.  A new relay, under load will have a ZERO Voltage (potential) if it reads higher than say 0.2 VDC…the contacts are pitted….a valuable thing to know and use on a MH.
 

 

[Russell]

Hey Steve, thank you. I emailed Hansar and sent the pics. I do like that there's a little LED on those new ones. Pretty easy to tell it's working or not. In that listing you can see a pic of the underside of the relay where the connectors are. I do see the embossed numbers there. Seems like I could just match up the numbers if mine have them. I just checked. The bottom of the relay is not embossed with those numbers. Is there a way to tell where the wires go? Thanks. 

[Tom Cherry]

Just now, Russell said:

Hey Steve, thank you. I emailed Hansar and sent the pics. I do like that there's a little LED on those new ones. Pretty easy to tell it's working or not. In that listing you can see a pic of the underside of the relay where the connectors are. I do see the embossed numbers there. Seems like I could just match up the numbers if mine have them. I just checked. The bottom of the relay is not embossed with those numbers. Is there a way to tell where the wires go? Thanks. 

See my above post…just ordering and swapping without testing and troubleshooting first may be wasted or expensive.  They are pretty robust.  Knowing what the circuit controls and what and where the switched outputs go is the key.  Until you determine if they are opening or closing correctly, then you don’t know.  First check the control circuits and verify that the coils are getting voltage.  Then verify that the full current is passing through.  You can use, per my post, a VOM and measure the contact load….  

as to your question….  YES…look at the bottom.  Google Hamsar and Bosch 87/87A.  The coil will be “isolated”.  The 87A/30/87 contacts should be in a “cluster”. Take a picture of the bottom of your relay (this may be on your printshop).  Then disconnect the wires.  Use a VOM on OHMS.  85 and 86 will have some resistance.  
Next….put the VOM on the center terminal in the cluster.  It will be 30 or the common,  then the 87A will make a circuit between 30 and 87A.  Use a test 12 VDC to the 85 & 86.  That closes the relay or energizes it. NOW you will have a circuit between 30 and 87.  Thus, you know the pin numbers and orientation.

BUT…then you need to start troubleshooting….see if the relay operates as it should and the contacts are not high resistance.  If SO…then there is an issue with either the “volts” going to 30 or the relay coil signals.  

YES… You can buy spares and swap out.  But if the circuits are not functioning properly or you don’t have voltage going to the Isolator/maintainer or the maintainer  is defective, a new relay ain’t gonna fix that.
 

[MyronTruex]

Bosh Relay Pinout.pdfbosh relay posts.pdf Bosh Relays.pdfBosh Relays.pdf

[Tom Whitlow]

To keep it simple -  Take off the wires and apply 12v DC from any source to either 85 or 86 and a ground to the other. (I just used jumpers to the batt pos and neg terminals.) Listen and feel the relay as you touch the 12V wire.  If it's working, you should hear or feel it click. 

[jakarrels]

I was having same problem with my 2002 Windsor. After checking everything I put a volt meter on the battery maintainer center pole, it says negative , after checking, it turned out the wire that was connected was 12 volt positive. I removed that wire and ran a new wire to the ground bar. Working perfectly the last 2 years.

[Russell]

Had it always been doing this or did it just start out of the blue? Mine was working fine and then just stopped. Do you have any pics of this mod? Thanks!

[Tom Cherry]

7 minutes ago, Russell said:

Had it always been doing this or did it just start out of the blue? Mine was working fine and then just stopped. Do you have any pics of this mod? Thanks!

Russell, Your PICTURE shows a WHITE wire hooked up to the NEGATIVE Terminal.  ODDS ARE, that it is a GROUND.  BUT, easy to test with your VOM.  The "GROUND" or Negative wire that Jerome posted was a POSITIVE...as in, it was wired, incorrectly.  Easy test for you to do.  

If you did a SEARCH for the LAMBERT (which is what, according to the images online), I think you have....then used TOPICS in the Everywhere drop down menu, then here is what we have. Richard (Dr4Film) posted the manuals...which tell you how to test.

Your Lambert is wired correctly.  NOW, is it DEAD?  Maybe...Probably...as they were good, but not 100% and many have replaced them.  There is a LOT of units out there....if you want the THIEF style that steals voltage...

Amp-L-Start gets good reviews and folks here like it.  There may be others that work as well...some different brands...on Amazon.

OPPS...  Amp-L-Start appears to be "unavailable.... scroll down....the one man company is now a "NO MAN - RIP" company...

https://sprinter-source.com/forums/index.php?threads/116417/

https://www.bestconverter.com/AMP-L-START_c_211.html#:~:text=HOW IT WORKS - Connected between,your engine starting batteries charged.

Bottom line...  Your Windsor came with a circuit to make it work.  It did work.  NOW, the way to troubleshoot is to run the tests.  I would do that...a whole lot easier than doing the testing on the relays.  IF it checks out....then on to the "Hamsar" tests...which are bit more complicated.

However...  SOME of the Thieves on Amazon may work...as long as they are the same "KNOCK OFF" as the original Lambert.

NOW, many folks have just "had it" with 120 VAC Maintainers or the THIEVES ... and gone to directly to a REAL BiRD or Bi-Directional charging system.  Blue Seas makes the ML-ACR.  You can use that in the Search.  MANY topics, with instructions...and hardly a member who regrets the upgrade. In your case, my preference would be the SIMPLE one...  No FRILLS.  You replace the Boost Solenoid that you have.  There is a switch or button for Auto, Manual (ON) or OFF.  Most don't opt for running a 5 wire bundle up front.  When they need, if ever, a BOOST....they walk back....switch to Manual (ON) and do their trick....then back to Auto..  That will keep your Chassis Charged when driving.  

The "Thieves" like your Lambert steal power from the House....to keep the Chassis charged.  BUT, the Amp-L-Start, I think, had better safeguards than the Lambert....based on what I remember when I talked to some folks...it has been so LONG ago...I did spend time talking to whom I thought was the original "Lambert" or maybe the recently deceased Amp-L-Start owner.  BUT, when you get below a certain point....then the HOUSE will not or can NOT give voltage.  SO....if you store with POWER, then the ML-ACR is the nuts....it keeps both banks up.

Hope this helps...wish it was simple...as in "change this wire".  A quick test....is the white wire a GROUND...will tell you.  THEN...start with the Lambert protocols...

Keep up informed.

[Russell]

UPDATE: 

Tests run. Faulty relay. Relay replaced. All is good again. Thank you all for your kind words and advice. I'm very glad we have resources like this when we get stumped. There's a vast wealth of knowledge out there and you all are very knightly. 

 

Thank you!