Forum Discussion

sd2usa2's avatar
sd2usa2
Explorer
Nov 24, 2014

Electrical Problems! Chassis Battery / Alternator Issues.

I just got my 1st Class A RV for some future trips. It is a 2005 Four Winds Hurricane 30Q w/ Ford V10. I currently have it at my house while I fix things up and I decided to spend a night on it to give a test run. I had it plugged to a 15 amp outlet in my garage and I only used a 1200w oil heater inside to stay warm for the night. It worked fine and no breakers were tripped. But when I woke up, the chassis battery seemed to have drained. The radio wouldn't come on and the RV engine would not start or even make a whimper.

I put the chassis battery on a Battery Tender Plus 1.25amp charger and let it charge over 2 days until it was 100% charged. The RV started right up and the battery seemed ok. BUT I don't know if I just noticed this or if this is new, but while the engine is running, I am not able to use the following items together. Any one of the items work alone, but if you try a 2nd one, it won't start.
1. Headlight
2. In-dash charge plug (12v)
3. In-dash A/C
4. Radio

The order of priority seems to be 1, 2, 3, 4. If I turn on the headlight, then all others go out. If I have something plugged into the charger (phone, gps) or try to start the A/C, then the radio power goes out. Also, when the A/C is on, the fan is very weak and I can barely feel it blowing. This is regardless of whether the engine is on or not.

I am thinking that this may be an issue with the alternator, but I wanted to ask the knowledgeable gurus on here before I started tearing anything out.

I charged the battery this morning and took the Battery Tender off so I am curious to see how the battery is doing tonight. I had the chassis battery switch to the off position this morning so hopefully nothing was draining it, but I'm not sure what is going on.

Any help in the right direction would be appreciated.
Class A

26 Replies

  • Dale_Traveling's avatar
    Dale_Traveling
    Explorer II
    Nov 26, 2014
    The BCC will prioritize charging power. With the engine running all alternator power stays with the chassis until the battery reaches at least 13.2 VDC. At that point the BCC will tie in the house batteries and start charging them also. Works in reverse when plugged in concerning the house batteries and the converter is happy. When you close the AUX START relay on the dash you're doing the same, cross connecting the two battery banks together so you can force charge off the alternator or get the generator running if the house batteries are dead. House batteries start the generator on the Hurricanes.

    I have the tech manual for the BCC if you want a copy (PDF format). Send me a PM with your email address and I'll reply with what I have.

    One idea to keep in the back of you head, the battery disconnect solenoids can and have failed and will either leave to stranded, kill the engine while going done the road or defrost the fridge and everything inside for you. Doesn't happen very often but can. If you know which power points are which in the BCC you can bypass the dead solenoid with standard jumper cables until permanent repairs can be made. Had the chassis solenoid die in the driveway. First problem I had with the coach.
  • sd2usa2's avatar
    sd2usa2
    Explorer
    Nov 26, 2014
    enblethen wrote:
    That could indicate that the ignition relay is not energizing. Chassis battery must be at a given level before the ignition relay will energize.
    Have you located your battery control center? make and model of the battery control center.


    Yes, it's in the front of the engine bay. I will take a picture of it when I get home and post it.
  • enblethen's avatar
    enblethen
    Nomad
    Nov 26, 2014
    That could indicate that the ignition relay is not energizing. Chassis battery must be at a given level before the ignition relay will energize.
    Have you located your battery control center? make and model of the battery control center.
  • sd2usa2's avatar
    sd2usa2
    Explorer
    Nov 26, 2014
    Dale.Traveling wrote:
    The AC to DC converters Thor used are either part of you AC breaker panel (the bottom half) or have a short power cord that plugs directly into an outlet on the back of the breaker panel. Pretty much you're going to need to get to the back of the panel. My coach it's all under the bed so all I had to do was pry off the thin wood panel covering the top (after raising the bed) and there was the my power transfer switch, converter and other power stuff.

    First thing to try is cycle the AC breaker. All the way off then all the way on. Next check the converter fuses or breaker. Depending on the converter manufacture the breaker can be a pop out push button looking thing that will look like a small push button but might have a number painted on the face. Pull it out and push it in. If fused check them with you meter not just a visual inspection. If the converter comes back to life you'll see it with the battery voltage increase or sometimes the converter will quietly hum.

    If the convertor has failed just insure the replacement is a smart or three stage type (lots of reading on what they are) of at least 50 amps capacity. Lots of on-line retailers have them at discounted prices so shop around for the best price. Since the 30Q doesn't have slides and probably no jacks your biggest DC power consumer will be the furnace blower or generator starter so 50 amps will just about power everything when you have shore power with the battery giving you the extra amps when needed.

    Finding and solving this problem is a priority. Your coach won't work very well without reliable DC. No HVAC, water pump, fridge, ceiling lights, water heater, generator starting power and such. Not high power eaters but each use DC to power the controllers.

    Tell us what you find.


    I think I have the same setup as you. Under the bed on the right side is a panel cover for the AC breakers and DC distribution fuses. I reset everything and they all seemed ok. As you mentioned, there is a wood panel that covers the right part of the bed when I open up the bed lid. I haven't yet pried it off but as soon as I have time, I will take a look inside. Thank you for the pointers. Dale: You have definitely been helpful.

    Here's what I saw:
    https://drive.google.com/a/hightideprop.com/file/d/0BxibHClKNcc5T1IxZmUwOVRtNW8/view

    https://drive.google.com/a/hightideprop.com/file/d/0BxibHClKNcc5c1g4ZHBtWGMzVU0/view

    As another aside, this morning, I tested the battery again and it's a lower 12.3v and although the engine started up, the dash radio and plug would not work again when the headlights were on. So they definitely seem to be dependent upon the voltage of the chassis battery being sufficiently high. I observed the chassis battery voltage being spiked up to 14.3 when the engine was on, but the house batteries were at 12.8 but did not spike up when the engine was on. So apparently there must be some sensor that detects if the chassis battery is low and the alternator must focus on charging only the chassis battery.

    I looked at the RV manual to see if there are more helpful info, but it is very cursory and did not have any useful info.
  • fourmat's avatar
    fourmat
    Explorer
    Nov 26, 2014
    Canadian Rainbirds wrote:
    I would suggest a higher capacity charger for those emergency moments. 1.25A will barely make a dent in big deeply discharged batteries. At a voltage of 12.9 it may not have reached it's maximum charge. Was the battery voltage still rising or did you just stop at 12.9? Normal charging with a smart charger is to take the battery up to at least 14.4 until the voltage stops rising. A float (maintaining) voltage is usually around 13.2 or so give or take a decimal or two.

    I suspect the battery has reached or past it's "best before" date.

    A hydrometer will tell you the real story.
    or take the battery to auto parts store and have it load tested most do it for free But my guess is battery is beyond service life
  • Dale_Traveling's avatar
    Dale_Traveling
    Explorer II
    Nov 26, 2014
    The AC to DC converters Thor used are either part of you AC breaker panel (the bottom half) or have a short power cord that plugs directly into an outlet on the back of the breaker panel. Pretty much you're going to need to get to the back of the panel. My coach it's all under the bed so all I had to do was pry off the thin wood panel covering the top (after raising the bed) and there was the my power transfer switch, converter and other power stuff.

    First thing to try is cycle the AC breaker. All the way off then all the way on. Next check the converter fuses or breaker. Depending on the converter manufacture the breaker can be a pop out push button looking thing that will look like a small push button but might have a number painted on the face. Pull it out and push it in. If fused check them with you meter not just a visual inspection. If the converter comes back to life you'll see it with the battery voltage increase or sometimes the converter will quietly hum.

    If the convertor has failed just insure the replacement is a smart or three stage type (lots of reading on what they are) of at least 50 amps capacity. Lots of on-line retailers have them at discounted prices so shop around for the best price. Since the 30Q doesn't have slides and probably no jacks your biggest DC power consumer will be the furnace blower or generator starter so 50 amps will just about power everything when you have shore power with the battery giving you the extra amps when needed.

    Finding and solving this problem is a priority. Your coach won't work very well without reliable DC. No HVAC, water pump, fridge, ceiling lights, water heater, generator starting power and such. Not high power eaters but each use DC to power the controllers.

    Tell us what you find.
  • enblethen's avatar
    enblethen
    Nomad
    Nov 26, 2014
    Have you located your 12 volt DC power distribution panel. Normally next to the 120 volt AC breakers behind a small metal plate.
    It is possible that the converter is in the same area. It is also possible that the converter may have reverse polarity fuses near where the 12 volt wiring terminates. it is also possible that the main fuse from the converter in the 12 volt distribution panel is bad.
  • sd2usa2's avatar
    sd2usa2
    Explorer
    Nov 26, 2014
    Very strange findings. This morning I took the chassis battery out and topped it off a little bit with distilled water. Found 1 cell with slightly low water. It was at 12.63v in morning and same at 4 pm when I got home. I took it to a battery shop and they said it's older but still has life left in it. Should be good for another year or two with care. I took it back to the RV, cleaned the electrodes and the connectors and reconnected it. The RV started with no problems and EVERYTHING WAS WORKING! Weird!

    I checked the voltage at battery before starting up and it was 12.6, and after staring up, the alternator kicked in and it was at 14.28. Same for the house batteries. It was 12.89 before starting up and it was 14.28 with the engine on.

    I then turned off the engine and hooked up the RV to shore power at 15amp power cord. The AC system kicked in but neither the house batteries nor the chassis battery voltage went up. It looks like when I plug in, the AC system runs, but the batteries are not charging up at all. I'm assuming then that this means that the converter is not working? If so, where do I find it and which one should I replace it with?

    I think Dale has it right that the converter maybe the culprit. A weak and older chassis battery that was inadvertently drained (maybe I left the headlights on somehow???) masked the real culprit.

    I found and opened up the BCC in the front of the RV but I'm not sure where the converter is. I was expecting to find a small standalone box, but not finding it.
  • sd2usa2's avatar
    sd2usa2
    Explorer
    Nov 25, 2014
    Dale: When the battery was initially dead, the steps did not extend/retract at all. But after it was charged, the steps worked fine.

    Thank you for all the advice. I also found this video which helped me a lot as well. It explains how you can find out whether you have a bad battery or a bad alternator.
    https://www.youtube.com/watch?v=_1q40V-BPQc

    This showed how to test the battery.
    https://www.youtube.com/watch?v=LGB6ZEjGm7Q

    I'm planning on running the diagnostics shown in the 2nd video to see where the issue may lie. I will report back. Darn day job is getting in the way of my RV repair career.
  • Dale_Traveling's avatar
    Dale_Traveling
    Explorer II
    Nov 25, 2014
    I may have gotten a bit away from the original question and focused more on the overnight charge or lack of. Do Brett's test first since all the stuff that won't work together are all chassis power related.

    Also do the steps extend and retract OK? As built they are powered by the chassis battery and will start acting up if the voltage drops.

About Motorhome Group

38,721 PostsLatest Activity: May 24, 2025