House battery not charging while driving

[twinboat]

That is the house battery disconnect relay ( solenoid ) controlled by the switch near the side door. It's not your problem.

It is a latching relay and locks on or off by the switch. If you get 10 volts on both sides its latched on.
It needs to be on fore the cinverter/charger to charge the house batteries when on shore power. Nothing to do with alternator charging.

Look in the Ford fuse box's for a bad fuse.
My 2000 class C had a inline fuse near the alternator for the under hood solenoid.

[rarebear.nm]

The solenoid under the hood looks like a starting solenoid. I doubt that it plays with the RV house batteries.


The second relay is much more of what I would expect the solenoid to look like. But the wires on yours appear to fairly corroded. That can account for some problems. I would get all of those connections cleaned up. The fuse should be replaced, it is there for a reason, usually. Try to check on the label of this solenoid and see if it reads continuous or latching. This makes a big difference in how to proceed. With those fuses, I'm guessing this is a latching relay, maybe not. Need to see the label.

[twinboat]

Originally Posted by rarebear.nm

The solenoid under the hood looks like a starting solenoid. I doubt that it plays with the RV house batteries.


The second relay is much more of what I would expect the solenoid to look like. But the wires on yours appear to fairly corroded. That can account for some problems. I would get all of those connections cleaned up. The fuse should be replaced, it is there for a reason, usually. Try to check on the label of this solenoid and see if it reads continuous or latching. This makes a big difference in how to proceed. With those fuses, I'm guessing this is a latching relay, maybe not. Need to see the label.

10 volts on both sides means it's a disconnect solenoid for the very low 10 volt house batteries.

The one under the hood has 10 volts on one side and 12 volts on the other side, evedeince that it's a isolation solenoid.

Solenoids don't all look the same .

[THenne1713]

OK, (under hood) the Large RED Wire goes from solenoid thru that circuit breaker (beside solenoid) and will go back to a similar breaker near COACH BATTERY (with battery on each end, you have to PROTECT each end of wire/cable w/ breaker. I.e.= NO FIRES/ NO SMOKE). ORANGE WIRE should turn ON/OFF w/ IGN Switch and CONNECT to the other small EMPTY screw terminal BESIDE the white wire terminal. WHITE= GROUND WIRE TERMINAL. To TEST Solenoid, jumper from either large terminal on solenoid to the small, empty RIGHT terminal, and solenoid should CLUNK. TEST #2 With jumper installed, start engine, and see if you get the higher voltage on both large terminals of solendoid. If NOT, I recommend replacing both solenoid and the auto-reset circuit breaker. **-cont'd**

[THenne1713]

**-cont'd** IF ORANGE WIRE has no power with IGN=ON then I suspect you can find the orange wire UNDER dash, left of steering column, near drivers knee? If you connected, or even momentarily touched the orange wire to ground (the white wire) while energized, you blew a FUSE. *(Orange wire maybe at a plug that is unplugged, but maybe direct from switched section of FUSE BLOCK, or from a RELAY in ?

[papademuchos]

#twinboat is correct - the relay near the house battery is a latching relay. The number on the unit is KIB LR9806. A quick google search shows latching relay.

I have checked the fuses in the power distribution box (under the hood) multiple times - they are all good. One of them in particular is a 60 amp fuse specifically for "Auxiliary battery relay" and it's good. I've checked lots of fuses on the inside underneath the steering column - so far all good as well.

I replaced the 5 amp fuse in the latching relay and now in addition to getting 10 volts on the left and right posts, I also get 10 volts from the left, smaller post when the IGN=OFF or ON. Before I wasn't getting anything out of that. I'm also getting 10 volts from the right, smaller post when the IGN=ON (not off).

#THenne1713 I tested with a jumper from one of the large terminals on the solenoid under the hood to the small, empty right terminal and I did hear a clunk. And yes, with the jumper installed I get the higher voltage reading on the larger terminal that goes to the house battery. The house battery also read the higher voltage. So the solenoid is working when energized.

The orange wire has no power to it, with the key off or on. HOWEVER, with the orange wire connected to the small, right terminal I hear the clunk when I push the Aux Battery button. I wasn't getting that before. But, I still don't hear it under the hood when I turn the key, and there's still no extra volts flowing through from side to side when the IGN=ON, or the engine is running.

I hear a clunk or something like that coming from the back - I'm guessing the latching relay, as there are volts registered on the smaller right terminal (mentioned above).

Yes, in my testing I probably did touch the orange wire to the ground. So where would I find the fuse that it's related to? Under the steering column? Or is it an inline fuse somewhere along the path? As I mentioned before I tried following that one. It goes down below with the red wires and thicker black wire leading to the house battery. They come up under the plastic step on the driver's door and then "disappear" towards the back on the inside of the housing.

So if the orange wire is suppose to energize the solenoid, it's not getting power to do so.

[rarebear.nm]

The latching relay in the rear has three wires on the POS small post. One of them appears to orange. That may be the power source for the orange wire under the hood. The large black cable on the same POS side likely goes to the house batteries. There should be a small wire, often bare wire, from that large post to the small fuse next to it. A red wire comes from that fuse and goes to the small POS post. That is providing 12+ to that solenoid. Thus the switching appears to be done on the black NEG wire on the second small post. I can not see any wire coming the second fuse. That is sometimes used to power an LED indicating power is on for the coach side.


At this point I would disconnect the orange wire on the small POS post. Then using a long jumper wire connected to this orange end, any small gauge is fine, and run it to the other solenoid and test for continuity with that open orange wire. If there is continuity then that's where the power comes from. If not then may be a different orange wire, or the orange wire may be damaged somewhere. I always like having any wire that is run outside of the RV to be in plastic wire loom for protection. This is where an decent wire toner/tester can come in handy to trace a wire and the better ones can tell you where a an open or short exists. Most of them require power to be OFF. If the wire is damaged you may be able to repair the damage or run a new wire solenoid to solenoid. But first you need to find where that open orange wire goes.

Can you determine if the black wire on the NEG small post goes to a ground? If so it's not being used for switching.


Most of the latching solenoids I've seen have only one wire off the fuse where your red wire goes, but in your case there's also an orange and yellow wire on the small POS post. I don't know what that yellow wire might be used for.


Either way I would get all of those terminals on the latching solenoid cleaned up. That can be helping anything.

[twinboat]

You can find a new ignition powered source to close the isolation solenoid.

Find a wire that's hot only with the key in the run position, tap into it and run it to the proper continuous duty solenoid. Most fuse box's have ignition powered push on blade terminals.
Even the radio fuse may work.

[papademuchos]

Just to confirm, there is no fuse or wire setup on the bottom right side of the latching relay. Only on the left.

The dull red (kind of looks like it might be orange) on the small left post, along with the yellow wire go off and down and around with the other wires. They go underneath and to the left and into the next compartment, behind the water input, valves, tank drainage, etc. The shore power line is over there as well. The yellow and red get "lost" in the sea of wiring.



I have a spool of 17 gauge wire. I disconnected the orange wire under the hood and connected my wire to that, then went down to the back. I have continuity from the orange wire to the large black wire on the right side and a few of the wires connected to the positive terminal on the house battery (I remove the battery and separated the wires). I also removed the latch relay to clean it up and run my tests. There is no continuity to the dull red or the yellow wires.

I crawled underneath to follow the wires around and noticed a lone dirty orange wire leading to the back. It's tied off next to the spare tire and I do have continuity to the end of that one. Perhaps it was intended to connect with the trailer wiring? I'm not sure why it's just there and didn't go anywhere!



I also set my wire on the solenoid to the black wire / terminal that leads to the house battery. It has continuity on the right side / black wire, but not the left. It also has continuity with several of the wires that connect to the positive terminal on the house battery, but not all of them.

I need to clean it all up and put it back together. If it still doesn't work, I like twinboat's idea of just adding a new wire and connect from somewhere that's hot when the key is on.

[rarebear.nm]

I agree with Twinboat to just tap into another hot source that's hot on ignition. This will be the fastest way to get it working. I've done similar fixes before.


There are so many variations in how RVs get wired, and then there are all the owner mods. Myself included.


Good luck...

[CharlesinGA]

Originally Posted by rarebear.nm

A standard RV battery charging solenoid looks like this.


Attachment 358852


Here's a title from Amazon.


Cole Hersee 24213 12V 200A Continuous Solenoid

About $50, has silver-tungsten plated solid copper contact disk, will last like forever. Make a ground wire from one small terminal to a mounting bolt or other good ground, then put the activating wire on the other terminal (doesn't matter which small terminal is ground and which is hot)

I always recommend this as a replacement for the junk the RV mfgs install.

Charles

[THenne1713]

OK, (Other solenoid in pic w/ Black Cables) = Latching makes sense. Since you think this orange wire under dash maybe connected to AUX BATTERY SWITCH, then that would be where you would find the OTHER end of the Orange wire, if indeed this is Solenoid giving the CLUNK? You need meter or test light on the orange wire while pushing AB Switch to prove/ disprove? Or you may find the THAT clunk elsewhere? I know I have seen RVs from 1980s/early 90s w/ dual solenoids on firewall. (Mine, a 99/2000, has CHARGE on firewall and BOOST under step, but boost Rocker SWITCH is beside door, NOT on dash). IF this is the BOOST solenoid, then CHARGE solenoid is elsewhere? Or I have had some in past argue that (some) use only ONE solenoid for BOOST and CHARGE, but mine has two and have not found wiring diagrams for any using only one. I come from hospital background, so I want backup for the backup so that when it hits the fan... The dual solenoids also allows power from different sources to the different coils.

[THenne1713]

Re: FUSE for Orange wire: Fuse Panel DIRECTORY=SAME for Ford Econ 1995-2014, so guessing orange wire goes thru AUX BATTERY SWITCH to UNDER HOOD panel, Fuse #22, 40a, labeled "Trailer Battery CHARGE RELAY (modified vehicles only)". If dead, #22 gets its power from 60a #10 FUSE, which also feeds #14 for trailer lights. MY GUESS for the other loose orange wire in back by spare tire/bumper is that it would/did goto a 7-pin trailer harness B+ wire for TOAD? (thus the 40a?) IF YOU HAVE any plug-in relays in (and wired) slots marked "NOT Used" in the Ford Directory, they might also be involved?
* If you touched orange wire to ground when NO POWER on it, you did NOT blow a fuse, and this also true if an AUX BATT Solenoid? (because not pushing button to energize?)

*** IF THIS is BOOST and NOT CHARGE, then you need to find YOUR other solenoid

[THenne1713]

Re: FUSES for Orange wire: Also possible, (Panel by driver left foot) =
#15-(5-amp) "TRAILER BATTERY CHARGE RELAY" (i.e. Coil) or
#12 (15a) "AUXILLARY BATTERY RELAY" (but this if blown might give transmission symptoms, too?)