Testing Battery selnoid 87 pace Arrow

I having a few problems:

1: first no power to dash for: Gen, Step, Tank levels(LP,Water,Bat,Sewer)
2: When switching Battery disconnect ON/OFF (no clicking at selnoid)
3: Was recommended to check fuses @ selinoid all good
4: One of swiches now activates selnoid (clicking) but no dash indicators for RV

5: No problems starting RV

How can i test the battery selnoids?



Senior Member
Testing Battery selnoid 87 pace Arrow

There are two different batteries in a motorhome. The one that starts the chassis engine does not supply starting power for the genset or coach 12V loads. Have you checked the coach battery? Do things in the coach work if you connect to shore power? If the disconnect that you are working with is for the coach battery, have you taken a voltage reading to see if there is power from the battery to the isolator? You could use a jumper cable to connect from one side of the isolator to the other as a way to know if it is the problem. Or, lift the connections from the isolator and fasten the two together with a bolt. That will connect the battery directly to the coach loads, and it will harm nothing.
Testing Battery selnoid 87 pace Arrow

If the solenoid is open (off) the voltage will be different on the two large terminals. If the solenoid is closed (on) then I would expect the voltage to be the same on both posts.
Testing Battery selnoid 87 pace Arrow

What indicators are you referring to on the dash? If you are talking about battery gauges, they may be bad. After all it is an 87 and things don't last forever. To test the solenoid you must fist test and see if the wire to the small stud gets power when the switch is pushed. Since it is a latching solenoid test it for on and off. If you don't get power use a jumper from the battery side to the post and see if it works.
Testing Battery selnoid 87 pace Arrow

First Thanks for all your commets:

My RV is in Storage so I finally got a chance to work on it today.

1:Checked both Batteries for voltage.
RV= 11.97 Auto=: 12.48
Check while running
RV= 13.60 Auto= 13.45

Could the low voltage in RV be causing the selinod issue ?

The selinod that clicks seems to be for the Auto Battery.

The other selinod makes no noises when flipping switch.

When connected to shore power all interior has power.
The Panel for checking : LP levels, FreshWater level, Grey/Black levels : even while on shore power still does not work.

I can not start my Generator no power, does anyone know which battery is used for this purpose ( rv or auto) ?

I did not get time to remove the left and right post wires and tie together to see if this resolves the issue. Maybe Tuesday ?

Any thoughts on my progress?

Thanks agian...
Testing Battery selnoid 87 pace Arrow

Since the house battery voltage came up when you started the motor the solenoid is fine. The dash lights sound like a fuse or wiring issue and has nothing to do with the solenoid.


Senior Member
Testing Battery selnoid 87 pace Arrow

You most likely have two different solenoids. As Ben said, the one that allows the chassis alternator to charge the coach battery is clearly fine, but it sounds to me as though you have a battery isolator that shuts off the coach battery for storage and it is open. A 12V battery in reality ranges from about 12.5V when charged fully to 10.5V when discharged. The 11.97V is more than enough to operate any of the 12V equipment or to start the genset. Clearly you are not getting the voltage from the coach battery to the systems that need it. That could mean a bad isolator, an open fusible link or some other open circuit between the battery and the coach loads. I suggest that you trace from the coach battery toward the loads to see where you loose that voltage. Once you find a point where you have 12V and then one where you do not, look for a place in between to see if you have voltage. If you have voltage, then move toward the point where there was no voltage and check again. If you don't have voltage, move half way to the battery and check again. But unless you can see a solenoid or fusible link, this is about the only way to see where it is being lost.
Testing Battery selnoid 87 pace Arrow

Thanks to all.
What I found:
1: I tied the leads from the coach battery solenoid together.
Result coach as power to lights , can start gen etc.....
Question: Is there any danger or problem leaving it in this state ?

2: I cleaned all coach fuse connections with wire brush.
Results: power to coach dash lights working(water tank,lp level.....)
Question: Is there anything i can do to reduce the film build up on these connections ?

Thanks again for all the help.


Senior Member
Testing Battery selnoid 87 pace Arrow

What you have done is to prove that the problem is the isolation solenoid failure. I would replace it, but there is no problem if you do not. Many RVs do not have an isolator for storage of the RV and you can do the same thing by just lifting the negative battery cable when you store it. Or you could also install a manual knife switch to do that job. One thing that I would caution you is the you need to be very sure that the connection that you made will not short to the frame of the RV. If you leave it the way it is now, I suggest that you attach both leads to the same side of the solenoid to make sure that they don't move around. The only "danger" is that you coach battery will discharge slowly when stored if you do not isolate it in some other way.

Fuses do not usually need to be cleaned. It must have been a very long time since they were touched if there was enough build-up on then to cause any detectable effect. In more than 40 years of service work I remember very few times that I ever cleaned a fuse.
Testing Battery selnoid 87 pace Arrow

Thanks for your advise..

The build up seemed to be on the fuse holders, after cleaning them everything has been working.

Thanks Again