Coach Battery Switch

darzoom · 06-06-2011, 09:04 AM

I have a 2000 Jayco Eagle 26' with the "salesmans" Switch just inside the coach door. It has never lit up since I bought the unit used. Well, I replaced it with a new one and it stays lit (in the off position) when not on coach power. The light goes off when it is on coach power (switched on) using the battery.

Was the that way it was suppose to work? I tried reversing the two outside wires on the switch and it started blowing the 7.5 amp fuse in the box by the coach battery. I just switched it back and all is fine. So the question is, is there a schematic around that I might be able to see how it is suppose to be wired? It has a red, orange and white wire and the switch has two brass and one silver post. The silver post is one of the outside posts.

I have had my share if issues with the coach battery charging and had to replace the "Boost" switch solenoid to correct that issue on one trip. I also added a Black and Decker battery maintainer ($20 at Target) and wired it into the 120 when on shore power so the coach battery will charge when using the unit. I also put an in-line blade type dissconnect on the negative side of the coach battery to dissconnect the coach batery when in storage to stop the parisitic circuits from draining it dry in two weeks like it was before.

This light on the switch is just bothering me. Maybe I should never have replaced it.

Suggestion?

**FPM III** · 06-06-2011, 10:16 AM

Salesman's switch? That's a new one on me. I have to think this was some mod done to the trailer after it arrived at the dealer's. Sounds like a lot trouble; especially for you.

By what you describe in your posting, it appears there have been other modifications made to the electrical system of this trailer. A "boost switch solenoid"? I never heard of one either, and as far as I'm aware of, my trailer has no such "animal" like that inside. What's its purpose?

You say you had to install a Black & Decker battery maintainer to keep the battery charged when on shore power? That function is normally taken care of by the DC converter. What brand of DC converter is in your trailer? In 2000 Jaycos, it should have been a Todd Engineering. There were a large number of converter failures caused by overheating that involved a particular model of Todd Engineering converter (The problem was so widespread it eventually put Todd Engineering out of business). Maybe yours had one of those problem units and it was swapped out for some other brand and/or the electrical system was modified so that the battery was no longer able to be charged by the converter. My trailer has the newer model Todd Engineering converter and it's still in use today.

Hopefully there is some other member out there may be able to be more helpful.

Denise · 06-06-2011, 12:07 PM

Welcome to the Jayco Owners Forum DarZoom! Come on back and tell us a little about yourself. Don't be a stranger. When you get a chance, post some pics. And just curious, what is a "salesman switch"?

darzoom · 06-06-2011, 03:57 PM

Mine is a 26 foot class "C" on a Ford E450 chassis with a V10. It gets a whopping 10 miles to the gallon. But then I am moving my house down the highway.

The salesman’s switch is the switch installed at the factory on the wall to the left of the door when you step into the coach. It is on the wall shared with the Norge (refrigerator). It is called a “salesman’s” switch as when the unit is on the sale lot the salesman uses it to disconnect the coach battery from the unit to try and save the coach battery from running down.

It is also the one an owner uses to do the same thing. In reality, it does not disconnect everything from the coach battery as there are parasitic circuits (warning lights, radio lights, propane monitor’s and such) that continue to draw from the coach battery even when the switch is in the off position. The owners manual says to pull the 7.5 amp fuse from the panel where you hook up shore power to stop coach battery drain. I installed a blade type disconnect switch (about $25) on the negative terminal of the coach battery to accomplish the same thing. It keeps me from having to get on the ground to reach into the panel to pull the fuse.

The “boost” solenoid switch is a button to the left of the steering wheel on the dashboard. You press it when you want to use the coach battery to help start the engine if the chassis battery has ran low. It is connected to a solenoid that is mounted in the engine compartment next to the brake booster. When the button is pressed, it actually passes the voltage from the coach to the engine battery. I believe it is standard on that and most models to boost the starting as needed.

I recently did a cross country with the rig and was coming out of the Eisenhower tunnel into Denver when the Propane warning started sounding. I had driven from the Grand Canyon and the coach battery had completely drained. I pressed the boost switch to back feed from the engine to the coach battery to charge it and determine that the solenoid had gone bad.

The one thing you mentioned that I did not know was about the Todd Engineering converter. I need to check that and see if the rig has one. Again, I bought the unit when it was 5 years old so it could have been replaced before. If it is a Todd, I guess I will start looking for a replacement.

I did have the converter tested when in Denver and it was functioning normally. But overheating could be an issue that may be causing the coach battery not to charge. It does produce a lot of heat when in use. Maybe I should put a fan in the seat to draw the air out and keep it cool. I was thinking there may be a converter issue but the test in Denver has me second guessing. That is why I bought the $20 Black and Decker maintenance charger as I did not want to spent the big bucks in a converter right now. Once I find one at a reasonable price I will look into installing as hopefully a final answer to the charging issue. Right now, I solved the issue with only a $20 spend. I don’t do any dry camping anyway so I am good there. If I did I would run the generator as needed.

Thanks for all the useful information. Keep it coming!

darzoom · 06-07-2011, 09:06 PM

Anyone know of a schematoic so I can troubleshoot the switch?

darzoom · 06-15-2011, 09:33 AM

Well we are out this week and I just changed the switch back to light up when on coach battey. All the other stuff is no longer an issue. It has so far ben an unevenful stay as far as having to repair or troubleshoot any issues with the coach. Happy motoring!

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