MAYCO's 1982 310 TD

[mayco]

Performed Deans test 1 and 2 and everything checked good. Genset starts off the chassis battery. Still have the vacuum activated steps. I have not checked the wiring from the genset to the chassis battery though.

Just did an amp draw test on the chassis system at the battery. Looks like I have a .9 amp parasitic drain of some sort. So I need to track down whats up with that. Turned on some coach system devices while doing the amp draw test on the chassis battery and did NOT see an increase in the amps so it looks like the systems are indeed not commingling. Can you think of anything related to the generator that would cause a parasitic drain like that? Looks like Ill need to start pulling fuses one by one to at least track down the circuit thats causing the drain. Would a .9 amp drain pull down the chassis battery as far as it did over night?

Thank you guys so much for taking the time and consideration. I truly appreciate it, I hope you know.

Mike

[dadstoy]

I can't image that .9 amp would drain the battery overnight. I still suspect a faulty battery.

A few years back, I put a new Costco battery in my F150. On my way to Idaho towing my 20' enclosed trailer, I thought the starter was going out. Classic symptoms of a bad starter, and of course it couldn't be the battery since it was only a few months old. After driving a few hours and stopping and then trying to start the engine again is when the problem showed up...starter cranking slow when hot.

When I got to my brother's house in Coeur d'Alene, I talked it over with my brother...he is a 30 year airframe and powerplant mechanic that could rebuild your Pratt & Whitney turbofan engines with his eyes closed. We agreed it was the starter. I called the local parts house and as we headed to the truck to go downtown, I said, lets just check the battery before we go.

Battery had a dead cell.

I replaced the battery with a another new Costco battery and the truck has been running great for a long time!

I never thought in a million years that a new battery might be bad!

Mike, I can't say that it is your battery, but as others have said here, we will all probably have a good chuckle when it turns out to be something very simple and yet not obvious.

[mayco]

"Mike, I can't say that it is your battery, but as others have said here, we will all probably have a good chuckle when it turns out to be something very simple and yet not obvious."

I appreciate your optimism that I'LL FIND IT!!!!

[Kota]

I've heard that some coaches have a safety solenoid valve for the propane that is hot wired.

Just an idea.

Mine was factory wired so the coach battery solenoid had to be powered to connect the solar panels to charge the battery. That little bastard got hot and drew about 2 amps. The solar puts out 3 amps on a good day.

The solenoid would drain the battery in 2 days.

[ArtFJ1]

Hey Guys. An easy way to see if something is draining the battery is to get a cheap multimeter (like the one Harbor Freight sometimes gives away) and measure whether any current (i.e. amps) are being drawn when everything is turned off. All you have to do is disconnect the cable from the battery and then make the connection from the battery to the cable using the multimeter leads. Make sure the multimeter function is set to 10A and make sure the red lead is connected to the "10ADC" input on the meter. You can then measure how much current (up to 10 amps) is being drawn directly on the meter. The only caution is to not turn on any major appliance while you've got things connected this way. But even if you forget and do so and you accidently draw more than 10 amps, it will normally just blow the internal fuse in the multimeter, which is easy enough to replace.

Art

[mayco]

I agree Dean, I dont think that would drain the battery that far over night.

[mayco]

Im going to leave the coach systems off and the chassis disconnect on for tonight and take a reading in the morning just to get an idea of what that amp draw will do to the voltage. I checked my compressor system, which is hard wired with a relay, to see if it was doing something weird but it had no affect on the .9 drain. Unplugged my head unit, even though its wired to the coach system, that had no affect. Other than remove and replace, those are the only 2 things I can think of that I have modified to the 12v system. Upgraded many things, converter, lighting, exhaust fans, etc. but used existing circuit wiring for those things. But I just cant explain why that chassis battery got pulled down so far. Dean you may be right, it may be a bad battery and whatever test they did wasnt sufficient. Alternator is dead on. In the mean time...............Ill make sure to turn the disconnect off when sitting for any length of time. Not giving up yet though

Mike

[dadstoy]

Giving up is not allowed!

[mayco]

So......I did what I said, left the chassis battery disconnect turned on overnight with nothing turned on in the coach. Chassis battery voltage was at 12.3 yesterday afternoon, this morning its at 11.8. This would reflect the .9 amp parasitic drain I assume...BUT!...as I stated in a previous post, I did the same test earlier in the week but ran the two ceiling vents overnight and in the morning the chassis battery was down to under 10 VOLTS. I realize this test is kinda remedial but doesnt that difference in voltage seem to indicate that those ceiling fans had SOME affect on the chassis battery??? Yet with the coach batteries disconnected the ceiling vent wont run.......hooey. WTH is going on.

Electricity is magic.....Im convinced

Today Im going to try and track down that parasitic .9 volt drain on the chassis battery. But I dont get why I had such a difference in voltage on the two test results with the only variable (that I can think of) was running those ceiling vents.

Thanks to all of you for the input and consideration. I really appreciate it.

Mike.

[bkahler]

Originally Posted by dadstoy

I never thought in a million years that a new battery might be bad!

Mike, I can't say that it is your battery, but as others have said here, we will all probably have a good chuckle when it turns out to be something very simple and yet not obvious.

I had a 6 month old battery in my Cushman Truckster and one day it decided it didn't want to start anymore. I charged it and tried again and it still wouldn't start. Took the battery back to Advance Auto and they tested it. Their first computerized test said the battery was ok. The clerk then asked if I wanted to wait to see if a load test would indicate anything. Load test completed and the report stated "replace battery".

In this case only a load test indicated the battery was bad.

[mayco]

Well looks like I should do the same Brad. I took it to Advance yesterday but apparently they didnt do that type of test on it. I should specify that I want a "load test"??

[bkahler]

Originally Posted by mayco

So......I did what I said, left the chassis battery disconnect turned on overnight with nothing turned on in the coach. Chassis battery voltage was at 12.3 yesterday afternoon, this morning its at 11.8. This would reflect the .9 amp parasitic drain I assume...BUT!...as I stated in a previous post, I did the same test earlier in the week but ran the two ceiling vents overnight and in the morning the chassis battery was down to under 10 VOLTS.

I want to make sure I get things straight here. When you say the chassis battery was disconnected are you saying the battery cable was disconnected so there was absolutely no way any load could be on the battery?

If that's the case then your battery is bad and needs replacing. If the battery cable(s) were connected then it could be one of two things. A parasitic drain or a parasitic drain coupled with a battery that is bad.

Deans suggestion of swapping in a known good battery is a very good test to make.

I realize this test is kinda remedial but doesnt that difference in voltage seem to indicate that those ceiling fans had SOME affect on the chassis battery??? Yet with the coach batteries disconnected the ceiling vent wont run.......hooey. WTH is going on.

I think you've proven the fans are not connected to the chassis battery so that should just be a coincidence.

Electricity is magic.....Im convinced

Actually it's just smoke and mirrors

Today Im going to try and track down that parasitic .9 volt drain on the chassis battery. But I dont get why I had such a difference in voltage on the two test results with the only variable (that I can think of) was running those ceiling vents.

See comment above....

[bkahler]

Originally Posted by mayco

Well looks like I should do the same Brad. I took it to Advance yesterday but apparently they didnt do that type of test on it. I should specify that I want a "load test"??

Yep, load test. Takes between 20 to 30 minutes to perform. I went to lunch while they tested mine.

[mayco]

Thanks Brad, actually I had the chassis battery DISCONNECT TURNED ON, therefore chassis battery was connected overnight. But no 12v devices were turned on in the coach.

[bkahler]

Originally Posted by mayco

Thanks Brad, actually I had the chassis battery DISCONNECT TURNED ON, therefore chassis battery was connected overnight. But no 12v devices were turned on in the coach.

Obviously the trick is trying to find the load that is connected to the chassis battery that you haven't been able to locate as yet.

This is where you unfortunately have to test each and every device in the coach to see where it's getting power from. Something I've done from time to time when something like this is happening is to literally stand at one end of the coach and visualize what devices are in that area, such as outlets, clocks, wall chargers, cigarette lighters, etc. and then move to another area of the coach and add to your list. Might be a good idea to write this list down as you can then check them off one at a time after you've determined it is or isn't the cause.

Since it's the chassis battery the dash would probably be a good area to start. Most modern radios have a "memory" wire that is supposed to connect directly to the battery. There is a good possibility the problem you're having is something like this. The maddening thing is it can take a long time to work through the process.

Worse, it could be more than one parasitic load

Step controller
Radio
Clock
Night light
Compartment light
Gauge of some sort
Phone charger
And the list goes on....

Brad

[mayco]

Indeed it does. Ill pull fuses one by one and at least narrow it down to a circuit. It did come to me last night while sitting here on the couch and asked myself, " self, what could be switched on thats tied to the chassis fuse block that I wouldnt necessarily notice while sitting still?" Ive an after market cruise control that works quite well but I have no idea how its wired, I never turn it to the "off" position. I just leave it in the on position and engage it when needed. Ran another amp test this morning and sure enough, switched the cruise control to the off position and the amp draw dropped by about .3 amps........so there was part of the parasitic drain right there. Woooohoooo, gotta celebrate the small successes. So now down to .6 to 6.5 amp drain.

Now whats that tell me? Well obviously I need to spend more time sitting on the couch to troubleshoot this thing..

Mike

[bkahler]

Originally Posted by mayco

Indeed it does. Ill pull fuses one by one and at least narrow it down to a circuit. It did come to me last night while sitting here on the couch and asked myself, " self, what could be switched on thats tied to the chassis fuse block that I wouldnt necessarily notice while sitting still?" Ive an after market cruise control that works quite well but I have no idea how its wired, I never turn it to the "off" position. I just leave it in the on position and engage it when needed.

Wow, that's one I never would have thought of. The cruise control power should be coming off of the ignition side of the switch. I'd look into changing that one. I installed a Rostra cruise control on the 310 and I'm pretty sure it's only powered from the ignition side. Guess I should check that out before the 310 moves to it's new home.

Ran another amp test this morning and sure enough, switched the cruise control to the off position and the amp draw dropped by about .3 amps........so there was part of the parasitic drain right there. Woooohoooo, gotta celebrate the small successes. So now down to .6 to 6.5 amp drain.

Finding that last little bit is probably easier said than done

Something to consider here is the fact that the problem seems to be intermittent. If that's the case then it sure sounds like something that you have control over via a switch of some sort.

Now whats that tell me? Well obviously I need to spend more time sitting on the couch to troubleshoot this thing..

Mike

I like your way of thinking!

[Kota]

Your air conditioning units probably have 12 volt control systems. Turn the AC power off and the units on. You will probably see the lights come on.

[bkahler]

Originally Posted by Kota

Your air conditioning units probably have 12 volt control systems. Turn the AC power off and the units on. You will probably see the lights come on.

Kota, I have not seen any 12vdc circuits going to the air conditioners before but then I haven't dealt much with the newer rigs. It's going to be interesting to see what Mike ends up finding when it's all said and done.

[Kota]

Originally Posted by bkahler

Kota, I have not seen any 12vdc circuits going to the air conditioners before but then I haven't dealt much with the newer rigs. It's going to be interesting to see what Mike ends up finding when it's all said and done.

http://www.dometic.com/QBankFiles3/E...nual_17591.pdf

Check out section D in the installation guide: Connection of low voltage wires.

Sneaky little bastards.

Bet the fridge is a parasite too!