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Help from the road - isolator clicking when on 12v fridge; lights dim when multiple on


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Hey all, 

 

Seeking help from the road, since I don’t have lots of time to research. 
 

We got an 87 Sunrader yesterday and it was having a sort of strange electrical issue when not on shore and using just 12v. The isolator seems to be clicking when on 12v fridge only while the vehicle isn’t running. I know we will run propane or shore when the vehicle is off usually, but I wasn’t sure what this was about.
 

Also, the outside light at the door when switched does the same click when turned on and the engine isn’t running. It’s the only non led bulb. In this same situation, when on just 12v, it seems having on more than 1 light draws power away from the others pretty good too. 


It has a dual battery system with two yellow top Optimas that is seen pictures of a solid charge. 
 

We would majorly appreciate any thoughts. 

 

 

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This is hard over the net, but here goes...

1. Get a cheap voltmeter, https://www.harborfreight.com/electrical/electrician-s-tools/multimeters-testers/7-function-digital-multimeter-63759.html

2. Check the polarity of the house battery. "NORMAL" color code does not apply to RV's. "Standard" RV colors are white is ground and black is +. House batteries are often hooked up wrong. Using the ohm function on the meter will let you check the ground

3. Find the click, if the batteries are wired OK then you may have a bad circuit breaker. Most of them in the 12v wiring are auto reset so you get the clicking when they reset and then trip again and again.   Most of them look like this, with a metal or plastic case.  https://www.delcity.net/store/Auto-Reset-Circuit-Breakers-!-12-volt/p_198669 

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The battery isolator on my camper went bad and needed to be replaced. I agree with WME you should check your circuit breakers. There will likely be one near your RV battery bank, and there could be a another near the battery isolator in the engine compartment. Mine is mounted on the firewall. I replaced them after discovering the one near my camper batteries failed. Find where that clicking sound is coming from exactly. Will help narrow it down.  I don't think the isolator has moving parts that would click. 

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Thanks y’all, it really seems to be that the isolator itself is clicking. I’ll inspect the breakers as noted and report back. 

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Do you have a solenoid isolator (35mm film can) or a diode type (box with fins)??

AGAIN check battery polarity.

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You mentioned having 2 yellow top batteries. Are both batteries for the coach? Or is one to start and one for coach?

If both yellow top batteries are for the coach check to ensure that they are wired in parallel and not series. You should have no positive post connecting to a negative post or chassis ground  on the two batteries.

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Quite often battery are not marked. The + post is all ways bigger then the negative. The click I'm going to bet is the charger/converter it is very common issue with reversed battery polarity. A lot of DC stuff doesn't really care about polarity the charger/converter does.

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23 hours ago, WME said:

Do you have a solenoid isolator (35mm film can) or a diode type (box with fins)??

AGAIN check battery polarity.

It seems to be the solenoid type. I’ll post a pic. 
 

 

 

 

Will pop the hood in the morning too to check the basic wiring. Grabbing a voltmeter tomorrow as well. 
 

The click is 100% the isolator and happens when the truck is either all the way off or in the ACC position. If the key is in the “on” position, it doesn’t click for the fridge 12v or the outside light. No other items cause the clicking. He did put in Hella flood lights in the front that I recall also causing it to click. Perhaps I need to disconnect any associated wires for those and see how it shakes out too. 
 

Im going to take a video too. 

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Should look like this 

Tekonsha Battery Switch, 3 Terminal, 12 Volt Continuous Duty

or this

Tekonsha 7001-S 4-Terminal 12V Battery Isolator

These are from Tekonsha and they were what was in my Sunrader from the factory. Since the brand was still available I replaced mine with one from them. 

Linda S

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Most likely you have the single small wire isolator usually the two wire is used for transmission starting isolation. The small wire is for the key switch. So there are two type of relays that look exactly a like that one is strictly for starting the engine it can not be use as an isolator relay it will over heat and eventually fail the other is continues duty it can stay on indefinitely might get a little warm but not hot if it's hot it is the wrong relay. The small wire in the case of the isolator is what engages the isolator nothing else. Volt meter/test light at this point is your friend. With the key off there should be zero voltage at the small terminal. The case of the isolator relay it needs a good body ground to work properly if it is poor this could be your clicking issue, poor grounds can do some very strange things . With the volt meter one probe to a known good ground the other to the case of the rely there should be zero voltage when it's on. If it has two small terminals one should have a small wire going to ground for RV use. Can't see it from my house so I hope this will work for you.

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New solenoid isolators can be bought for cheap. For $20 it might be worth it.

Not knowing the age of the one you have now a new one can’t hurt.

I’m using this one I bought on Amazon. No problems after 5 years.

 

 

Stinger SGP38 80-AMP Battery Isolator and Relay,BLACK https://www.amazon.com/dp/B001HC6UJ0/ref=cm_sw_r_cp_api_i_9C59CANTS50RZND27A8F?_encoding=UTF8&psc=1

Edited by fred heath
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Just checked my isolater is the 4 pole one. Front connectors are left to exciter and right to body ground. They don't click, ever. Only thing that could be clicking is the circuit breaker next to it. 

Linda S 

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Don't think I have ever seen a circuit breaker connected to the high current side of an isolator. Low side maybe clicking would lead to a faulty solenoid however.

 

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Adding photos. I removed the small red and black wires from the batteries that come from the fog lights that crossed the two batteries. One wire went to each battery. Still got the same clicking though.

 

Got and checked the batteries with multimeter. The starter battery is perfect, but the 3 year old house  battery seems the be at 

11.5 and comes back up with the truck running, meaning I think that the alternator works. 

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Going to replace the house battery with a Walmart 12v deep cycle group 24 and see if that solves the issue. The optima would get us through the night after a good drive but eventually the furnace wouldn’t ignite from what I researched here and elsewhere as low voltage. 
 

I opened up the fuse/breaker box by the isolated and it looks like the 80a one could be toast? I’ll post a pic and try to look up what it breaks. 

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You really need that multi meter. That way you could check the charge at the house battery with the engine running and see if it's getting the proper power. You can also take the Optima to any autoparts store and have it checked. 

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1 hour ago, linda s said:

You really need that multi meter. That way you could check the charge at the house battery with the engine running and see if it's getting the proper power. You can also take the Optima to any autoparts store and have it checked. 

For sure. I did use the multi meter on it, and it showed 11.5 earlier today after a long drive, but then after a short drive, it’s showing 12.3. I think we’ll put the optima on a friends charger overnight in Colorado and maybe try a group 24, if it fits. 

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if you have 11.5v  with the engine running, either the alt. is bad, or the isolator is bad.  should be 14.2

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20 minutes ago, extech said:

if you have 11.5v  with the engine running, either the alt. is bad, or the isolator is bad.  should be 14.2

It was 11.5 engine off. It was climbing when the engine was on. Seems it was trying to recharge. Sound right? 

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Use a separate battery charger on the house battery, charge it for 24 HR. Measure voltage as soon as you remove the charger. Measure the voltage again after 12 HR.

13.5 v + off charge, 12.5v + after 12 HR of rest. That will test the battery.

The alternator is a simpler test  13.7v + when engine is running.

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The shot gun approach generally leads to an empty wallet. Can you take some pictures of just what you have?

 

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Posted (edited)
6 minutes ago, Maineah said:

The shot gun approach generally leads to an empty wallet. Can you take some pictures of just what you have?

 

I do. I’ve tried to post them from my phone, but it keeps timing out. Just hard from the road covering miles each day. Mega appreciate each reply and everyone’s help. 
 

I removed the two smaller red and black wires that power the fog lights that did cross the batteries.
 

We fully Charged the house battery last night and it’s showing 12.8 without the engine running. 

 

I’d looks like maybe my 80amp fuse is bad, but my alternator is charging from what I can tell when the motor is on and the batteries read higher than full or gain when low related to the house battery 

 

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18D395C4-9A87-4CEE-A0A8-C68E9A4148FF.jpeg

Edited by wadingthroughlife
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I'd start by testing the alternator. With the engine running at (or above) 2000 rpm you should see 14.4v (+/-  about 0.2v) across each of the batteries. If either or both batteries are at 14.4v the alternator is OK. If only one is at 14.4v the isolator looks to be faulty or a wiring issue.

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I didn’t see this mentioned, but there is one possible gotcha on these old Toyotas. Make sure when you are testing the battery and alternator right after you’ve started the vehicle, that you rev it up a little bit to make the battery light and brake light go out.  I would assume that you know this, because you’ve been out on the road with it, but just in case…

 

I didn’t know this and I potentially replaced a perfectly good alternator when I first got mine. 

Edited by thewanderlustking
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I appreciate that; I actually have intermittent brake and battery lights flickering while I drive too. Previous owner said it hadn’t done it before he recently cleaned the engine with some spray and hose off stuff which I wasn’t expecting to have happened. 

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Alternator is not charging properly. Check the belt but if it feels tight and looks good you need a new alternator. Don't know what he used but since wire wrapping on the alternators is open I'm sure some cleaning agents could have damaged it. 

Linda S

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12 hours ago, thewanderlustking said:

I didn’t see this mentioned, but there is one possible gotcha on these old Toyotas. Make sure when you are testing the battery and alternator right after you’ve started the vehicle, that you rev it up a little bit to make the battery light and brake light go out.  I would assume that you know this, because you’ve been out on the road with it, but just in case…

 

I didn’t know this and I potentially replaced a perfectly good alternator when I first got mine. 

 

Agreed - this is why I suggested running the running at 2000 + rpm. All alternators produce less output at low rpm. I would do the tests that I outlined, check the belt as suggested, and ensure that the alternator is well grounded (test for continuity between battery -ve and the alternator body)

Edited by neilp
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12.8 volts is a fully charged resting battery. The 80 fuse looks fine to me it by the way is bolted in it will not pull out.

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Hi all, 

 

Being home allows for more time to look at this.  Thanks all so far! 
 

What I think I’m seeing is on the left, for the starter battery, the alternator is going direct to the starter battery, the starter to the isolator, and also under the fuse box. It is also grounded with the negative. 
 

On the right, the house battery has a positive and negative from the winch, a positive to the isolator, and a negative small line to the isolator. 
 

The isolator in turn has a positive going to the circuit breaker and back to the panel, but also one coming off the house battery at the same pole. 
the isolator also has the small black negative to the house battery, a wire on the other middle pole to the yellow plug and silver box mounted on the left. It gets a power cable from the starter battery too. 
 

Im getting proper alternator to starter voltage and hood starter battery sitting voltage.

 

im getting nothing to the house battery from the alternator and good resting voltage from a stand alone charge. 
 

 

Shouldn’t the alternator go direct to the isolator at the starter battery connected side? 
 

what’s the positive to the fuse box off the starter battery? Should that connect elsewhere? 
 

thanks!!!!

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Also in the rear, it looks like newer power cable was run to the panel from the engine bay. The connection should probably be heat shrunken at least I would assume. It’s pretty well connected though. 

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138BCF49-5AF4-4300-8574-55F603E02B8E.jpeg

A23D20AD-02C2-4D7D-9BEA-E0690B5417FA.jpeg

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I hate long distance electrical problems.

But on to the next step, the small red wire on the isolator should be a switched 12v. Ignition off, engine off, there should be 0v on the terminal. Ignition to run and engine off, there should be 12v on the terminal. Ignition to run and engine running there should be 12v+ on the terminal.

Let us know.

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11 minutes ago, WME said:

I hate long distance electrical problems.

But on to the next step, the small red wire on the isolator should be a switched 12v. Ignition off, engine off, there should be 0v on the terminal. Ignition to run and engine off, there should be 12v on the terminal. Ignition to run and engine running there should be 12v+ on the terminal.

Let us know.

Will do.
 

Can you confirm, if in general, the left side post of the isolator ( receiving the starter battery single positive cable currently) should actually also get the alternator power versus it going to the starter battery itself? It seems like the starter battery is getting the direct alternator voltage as well as connecting to the alternator fuse currently while also running to the left post of the isolator. 

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The online instructions don’t seem to show where the alternator actually connects in. I’ve come across diagrams showing it both ways unfortunately. 
 

actual one in truck

https://www.rvupgradestore.com/v/vspfiles/assets/pdf/7001S_WiringDiagram.pdf


 

There’s a photo attached of a different one too, but not sure it’s helpful. It showed the alternator going to the isolator I do believe. 


 

Thanks for the continued help!

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64417A25-3F44-4C60-BF90-D371C552BAFB.png

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