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techheadgw · 05-04-2015, 08:03 PM

A story ... then I need your advice/opinion:

I am a new RVer, just bought a one owner, 2000 Tiffin Allegro Bus last week. Drove it home 1,000 miles. Everything was fine for the first 3 hours or so. Suddenly, the transmission shifted into 4th. All gauges went out. We were suddenly traveling about 50 mph down the interstate. Got off the freeway at the next exit, found a good place to park and turned the coach off. Tried to restart. Nothing. Tried the generator. Nothing. Eventually, called a tow truck to give me a jump start. We quickly restarted the generator, but the chassis engine would not start, his jumpstarter was not powerful enough ... though he had started trucks before with it. Just an indication of how empty the batteries were.

Eventually discovered that both sets of battery (house and chassis) were dead as a doornail. We got a guy with a more powerful jumpstarter to come help us start the main engine, but neither battery was charging. Both were dead/dead and if we removed the jump starters, the engines would die. We had AC from the generator, but no DC. In fact, if you turned on a 12 Volt light, the generator would die.

The tow truck driver (what a godsend) was quite knowledgeable and suggested that we go to Walmart, get a battery charger, plug it in to the AC and charge the batteries ... jumping them together. So, that's what we did.

Charger connected to the chassis batteries, jumper cables from the chassis batteries to the house batteries, and let the generator run all night. In the morning, started it up and it ran fine. Drove 800 miles, getting home at midnight (yes, even using the lights worked), keeping the charger going the whole time.

So now the question is: What is wrong? Remember, I have just purchased this coach, so I don't really have knowledge of everything that has happened to it over the years.

I was able to track down the original owner and ask him about it. He was very helpful, but hadn't had any issues with it before this. I do know, however, that it has been a number of months since the coach was driven this kind of distance, and it was just "unmothballed" from winter storage prior to selling to an RV dealer. The previous owner said he noticed that even though it was plugged in all winter, that the house batteries would drop below 12, and then go back up the next day.

I have several theories:
- Both the Charger/Converter (replaced in 2008) and the chassis alternator (looks like it may be the original) are out.
- The charger/converter is super messed up and is sucking both battery sets dry
- Bad battery ... though I don't know how that could get both sets of batteries (dates: 2008 for house, 2013 for chassis)
- Bad Ground (original owner's theory)

Just so you know, I did not notice a battery light or the alternator gauge showing no charge while driving, but I will admit that as a new driver of this kind of rig, I was kind of consumed with keeping it between the lines. I have seen the battery light on occasionally since that time, but it goes back out again. Alternator charge indicator is on the low side of "Normal" range on the gauge.

One last piece of information: This morning, I moved the coach about a half mile to park in front of my house so my wife could clean out the inside. It started just fine, but the battery light was on, the alternator did not show up as charging and the strangest of all ... the accelerator did not work. Pushed it all the way to the floor and the engine just idled. Went outside and opened up the electrical panel basement door, looked to see if anything looked out of place, shut the door to the basement and ... the engine rev'd. Went back in and the battery light was off and the alternator showed charging.

So, there you have it ... a complete mind dump! Not a great way to start out my RV career!

Anyone have any thoughts?

PS. I do have an appointment at the local truck shop tomorrow to have the alternator checked ... and replaced if necessary. They don't work on RV's though, so I'm on my own for the rest of it. Of course, I can take it to the local RV repair place also, but ... rather figure it out myself (with your help).

Thanks,
GW

Skip426 · 05-04-2015, 08:16 PM

You've bought the battery charger , so charge the batteries for 24 hrs each then take them to nearest parts store for a load test , while they are out clean all the connections . While at the parts store buy a voltmeter / multi-meter, good ones are available for $20, this a tool you'll be using often.
If the batteries check out , you'll have to check voltages at the batteries , with the engine running, should get 13.8 > 14.2 volts if the alternator is working correctly. If no increase from non running then you probably have a failed alternator.

If you have erratic volts then every system in the coach can act up , throttle included, it's fly by wire.

Melmoses · 05-04-2015, 08:40 PM

There is a charge solenoid somewhere. Mine is in the rear PS compartment. If batteries aren't charging while driving it is probably that solenoid gone bad. There is lots of detailed information including wiring over on www.tiffinrvnetwork.com which is a Tiffin owners forum. Its free and I bet someone can guide you as they did me when I had a problem. The library is a fantastic tool on how do fix many issues. Try it and see if they can help you.

Melmoses · 05-04-2015, 08:46 PM

PS the house batteries are over 5 years old and should be replaced. Dead house batteries are the ones tied to the generator so that's why it wouldn't start. There is a switch that will tie both house and start batteries together if needed to the left of the driver seat. But if they are that dead it won't help. Good luck with ironing out your problems.