Any Help or Ideas for my problem?

[Aggiepi]

I am new to the RV world and have a 1996 national RV with 454 and Allison transmission. 6 weeks ago while driving to the in-laws to store the voltage meter on the dash went very low (almost nothing). I parked it at the in-laws and went back two weeks later to check it, then it started and everything ran fine but the voltage gage was still low. I checked the house batteries and they were not good (original from 96) and when checking the chassis battery, the longer the coach ran the lower it got(so I am thinking alternator). So yesterday I replaced the two 6v house batteries and tried to start...nothing. So I push the boost button...nothing. So I take the alternator off and put the chassis battery on charge. Get new alternator, start the coach and the voltage gauge is 13 or 14, Then withing like 5 seconds it goes to 0 and the coach sputters and dies. So I charge the battery again and re-start and the same thing happened. Also this whole time I have no power inside coach and generator will not start. I tried (but do not understand) how to test the converter (is is Magnatec 950 and the original). There are also several relays? solenoids? under the compartment by the converter.

[Aggiepi]

I am new to the RV world and have a 1996 national RV with 454 and Allison transmission. 6 weeks ago while driving to the in-laws to store the voltage meter on the dash went very low (almost nothing). I parked it at the in-laws and went back two weeks later to check it, then it started and everything ran fine but the voltage gage was still low. I checked the house batteries and they were not good (original from 96) and when checking the chassis battery, the longer the coach ran the lower it got(so I am thinking alternator). So yesterday I replaced the two 6v house batteries and tried to start...nothing. So I push the boost button...nothing. So I take the alternator off and put the chassis battery on charge. Get new alternator, start the coach and the voltage gauge is 13 or 14, Then withing like 5 seconds it goes to 0 and the coach sputters and dies. So I charge the battery again and re-start and the same thing happened. Also this whole time I have no power inside coach and generator will not start. I tried (but do not understand) how to test the converter (is is Magnatec 950 and the original). There are also several relays? solenoids? under the compartment by the converter.

[Tom N]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Aggiepi:
I am new to the RV world and have a 1996 national RV with 454 and Allison transmission. </div></BLOCKQUOTE>

FWIW, your Sea Breeze uses a GM 4 speed Hydra-matic transmission, not an Allison.

[Aggiepi]

Yeah it is not the original trans

[Bucky1]

It almost seems like the battery isolator(s) are cutting you off. Those batteries should not discharge in 5 seconds. Try checking the voltage at the batteries. I doubt that the alternator has anything to do with it either. Wish I had more suggestions for you.
I could throw out the old standby (check your grounds), which would probably be a good idea to make sure one is not hanging on by a thread.

[M&EM]

Edward,
Check Alternator and chassis battery terminals for tight connections and corrosion. Include the ground connections too.
Don't know if your 1996 NRV dc electrical system is similar to my 2003's. But if it is:
maybe there is a high current drain on the coach side of the isolation relay running down the 6 volt house batteries overnite. The isolation relay is de activated when neither system is above about 13 volts. The isolation relay also probably has a time delay after starting to allow the chassis battery some extra time to recharge energy used by the starter. After that time delay is over, the isolation relay connects both system together and loads the alternator and coach system down pretty hard. Since the 2 six volt batteries were fully discharged(overnite), their voltage would be low enough to cause engine ecm to quit and stall the engine. This could occur because of poor connection from alternator/batt/grounds

I believe this is how my system functions and would react to dead coach batteries after the isolation relay activates..
If you can find the isolation relay and disable it by disconnecting the heavy cable on one side to it, That should keep the two system apart and the engine may be able to run.

If true, then the problem is on the coach side.
If not, then problem is on chassis side.

Did I mention to Also check chassis ground connections/cables to the engine and chassis battery?

Marty

[Aggiepi]

The coach batteries are new (as of Sunday) and they do not loose the charge (two 6 v deep cycle). But when I switch from store to run, I get nothing inside the coach. The generator will not start and I can not use the "boost" button to start engine. So to start the engine I have to charge the chassis battery (it was low from bad alternator that I replaced). Even when I charge the chassis battery and start with the new alternator it only runs a few seconds.

That being said I have been reading my "Chevy" chassis manual and the Trailer Life Repair and Maintenance Manual this week , and will have a better idea of what to test and how the system works. And I will be checking every electric connection I can find for wire loose or corroded (thanks for suggestions).

[Redlands Truck and RV]

Edward,

I've read your posts twice looking for the age of the Engine or Chassis battery. It can't be the originial can it? How old is it? What condition is it in? Have you had it load tested?

My thinking is your engine battery is defective and acting as a dead short. We see this when the plates inside a battery touch. If your coach were here we would focus our diagnostics toward the engine side of your charging system.

[Aggiepi]

Redlands the engine or chassis battery is 4 months old. It is in good condition have not had any issues with it. Have only tested it with voltmeter and charger gauge.

[Redlands Truck and RV]

One would assume that a 4 month old battery is good, but we have seen stranger things. I would want to have it load tested to confirm it's good condition.

Feel free to call me, I have some other ideas.

Thanks,