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Fried · 11-14-2007, 03:27 PM

Hello all you Gurus in RV land.

Just purchased this motorhome, decent price, but the GENSET won't start. Looking at the codes (aren't computers great?) I get:

INVERTER POWER SUPPLY FAULT"”CODE NO. 46
(Low battery voltage or power supply device failure)
Corrective Action:
1. Avoid running the genset while cranking the vehicle engine in installations where the genset batteries are used to supplement the vehicle engine batteries.
2. Clean and tighten the positive (+) and negative (âˆ’) battery cable connections at the battery, vehicle frame and genset.
3. Recharge or replace the battery. Refer to the battery manufacturer's recommendations.
4. Install or service a battery charging system in the vehicle if the genset is not so equipped.

I can check the general conditions, but does a GENSET normally have a seperate battery? (Not on an older Winnie I had).

Seller replaced the house batteries (3x6 volt), coach starts with no problems. Charging system seems to work OK.

Any ideas are appreciated.

Fried · 11-14-2007, 03:27 PM

Hello all you Gurus in RV land.

Just purchased this motorhome, decent price, but the GENSET won't start. Looking at the codes (aren't computers great?) I get:

INVERTER POWER SUPPLY FAULT"”CODE NO. 46
(Low battery voltage or power supply device failure)
Corrective Action:
1. Avoid running the genset while cranking the vehicle engine in installations where the genset batteries are used to supplement the vehicle engine batteries.
2. Clean and tighten the positive (+) and negative (âˆ’) battery cable connections at the battery, vehicle frame and genset.
3. Recharge or replace the battery. Refer to the battery manufacturer's recommendations.
4. Install or service a battery charging system in the vehicle if the genset is not so equipped.

I can check the general conditions, but does a GENSET normally have a seperate battery? (Not on an older Winnie I had).

Seller replaced the house batteries (3x6 volt), coach starts with no problems. Charging system seems to work OK.

Any ideas are appreciated.

LVJ58 · 11-14-2007, 03:57 PM

Hi Fried, is your genset an Onan or Powertech? Also you mentioned the seller replaced house batteries 3x6v, house batteries. Usually 6v house batteries are either in sets of 2ea or 4ea, which is in yours? And when you say the genset won't start, does the starter crank the engine over and it won't start, or does in not crank at all? A bit of clarification would help in that area.

chasfm11 · 11-14-2007, 04:02 PM

I think that the solution to your problem will come when you have all of the power sources more clear in your mind.

Typically, the genset starts off the chassis batteries. Therefore the status of the house batteries would have no bearing on it starting or not. To prove that, you might try completely disconnecting the house batteries and trying to start the genset. On a side note, I'm not 6 volt expert but 3 batteries doesn't sound right to me.

Inverter power supply fault also doesn't sound related to me. The inverter is used to power 120volt appliances when you are not running the genset or plugged into shore power. Perhaps that is just extra text in the fault code description.

To help you, a little more information about your symptoms might help. For example, when the genset doesn't start, does the starter turn over and crank or does it just sit there? If it truly is a low voltage problem, I wouldn't expect to hear the starter.

The first thing that I would do would be put a volt meter on the genset starter's positive lug (with the other meter lead on a known good ground) and trying cranking the genset. If you are getting proper voltage, it could be the starter itself. If not, you need to figure out where the voltage is breaking down, assuming that it is good at battery. On my chassis batteries, I've had an intermittent problem where deposits would built up between the wires on the terminal, out of visual range. It took taking all the wires off of the battery lug to find that problem.

I'm not a guru at all so just understand that my ideas were worth what you paid for them.

RV Wizard · 11-14-2007, 05:30 PM

Fried, your Tiffin should be set up with 4 six volt batteries and if only three were replaced this could be an issue. Your Onan generator is actually a diesel powered large inverter. Verify that you have a good 12 (13.2) volt house battery source. Make sure the connections are clean and tight. Let us know what you find.

Fried · 11-14-2007, 11:18 PM

Thanks for the responses - will go and re-verify connections and number of batteries for each application. To answer the questions posed:

1. ONAN Diesel Generator
2. Won't turn over - just nice blinking lights at the starter switches indicating a fault.

Once I have re-checked everything - I'll let the group know.

Thanks again - any other ideas while I'm waiting?

racer0624 · 11-15-2007, 12:17 AM

Fried,
Earlier this year my Onan showed the same code and also only blinked at me when I tried to start it. It turned out to be a broken pin in multi-pin connector under the cover.

Fried · 11-15-2007, 01:24 PM

Hello folks,

Upon further investigation:

I do have 4 6V house batteries and 2 12V chassis batteries.

Have not disconnected the battery terminals, but I can't see any corrosion and the motor starts just fine - just not the genset - will investigate corrosion issue further.

Voltage meter for engine start shows everything in the "normal" range - 12-13.5 volts.

John's proposition is interesting - John - where under the cover - did the whole sound dampening cover have to come off, or just the access panels?

Thanks again -

racer0624 · 11-16-2007, 01:25 AM

Fried,
I have a 12.5 KW Onan but the start/run circuits are probably close to the same as yours. The connector was at the top front center under the cover. When the tech. pulled the connector apart one of the pins fell out. The work was done at Cummins/Onan Salt Lake City.

Cruzer · 11-16-2007, 04:05 AM

Hi Fried,

Your Phaeton's genset is an Onan 7500 watt Quiet Power diesel, same as what I had on my 2004 Allegro Bus. The genset's starter is powered via the house batteries, not the chassis batteries, so whatever the chassis batteries read doesn't mean anything. You'd have to check voltage at the house batteries. The actual cables connect at the junction panel near the batteries, along with the other large gauge cables that receive battery power. They also connect to the genberator set at the bottom-rear of the case. This is the first place I'd look for corrosion because it's out there, exposed to the elements. The studs and nuts are brass so be careful not to over tighten them or they may snap off.

Assuming that your batteries are all good (and that means all 4, not just 3) and that the cable connections are good, then you'd have to look further. The error code indicates that it's not seeing enough voltage to crank. It's possible that the buss bar inside the genset's cabinet may have a loose connection but that would require removing the top and side panels to get to it. Another possibility is a loose pin in the multi-conducter harness. There may be a wire in there that is used as a battery power sense and it may have an open connection.

NeilV · 11-16-2007, 10:56 AM

Can you jump start it? On my coach that is what I had to do when my battery bypass relay started to fail. It carried enough of a load to run the house lghts but not enough to start the generator.

Fried · 11-16-2007, 04:39 PM

Ok, slowly starting to understand how this BIG toy works,

1. Buyer beware - the individual who sold me this coach claimed to have replaced the house batteries - I doubt that after close inspection (tool marks, dirt patterns etc.)
2. Checking the charge state at the power center - battery condition has not improved after some 48 hous of being plugged into AC power with only batteries being charged.
3. Thanks to Mark, (after pouring over the electrical diagrams)- confirmation that the GENSET starts from the house batteris rather than the chassis batteries - will pull all 4 and see how many I need to replace at a local battery dealer.
4. Thanks to NeilV - I did think to try and jump from the chassis to house batteries - lack of success was probably due to the cold (but warm insides) and not properly hooking-up the jumper cables.
5. I did check the multi-plug as John suggested backed up by Mark - that seems to be OK - but the condition of the wiring appears be somewhat flakey under the tape I pulled off - that tape seems to be original since it comes from under the plastic conduit and around the exposed part of the wiring. Did undo and clean the gound connection - just haven't crawled underneath for the positive line-in connection - will check that as well.

I'm betting it is the house batteries.

A question - are GEL batteries worth the investment or should I stick with the tried and true wet cell?

Thanks again to all - this community is a great resource - I will report out on the results - and hope to encounter you folks as we begin to travel around this great country.

Route 66 · 11-17-2007, 03:16 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">A question - are GEL batteries worth the investment or should I stick with the tried and true wet cell? </div></BLOCKQUOTE>

We don't hear of many folks using Gel Cell batteries.

Some have installed AGM batteries and report that they are well worth the high price.

But conventional flooded cell batteries are by far the most popular because of the lower cost, and with proper maintenance, they do the job.

Fried · 11-17-2007, 12:52 PM

Hello folks,

Thoroughly frustrated. Batteries tested good - reinstalled them - cleaned up the Battery Box - now the charging monitor tells me everything is hunky dory - can hear the batteries charging/cooking. Cleaned every contact from batteries to GENSET to include ground cables - now only showing 6.5 volts at GENSET lugs - checked and rechecked battery conections - all appear to be correct - lights, slides and all other 12V systems work - considering running a direct connect line from batteries to GENSET or shooting the S*B - maybe extra "lead" will improve connectivity.

Just my rant - all ideas you folks gave me were great - just did not result in getting the GENSET up and running - might still be the multiplug - if I disconnect - can I still start the beast with a jump? I will probably try it -the multi-plug seems to be a control element - would the primary electric feeds to the coach still work if I disconnect it? I will take it to a shop if I need to - just like to putz and see if I can fix stuff myself before paying.

Thanks folks