Help with Solenoid? near battery isolator

[c3idotnet]

We have a 1991 monaco signature that we have put a lot of money in... After replacing the alternator, regulator and isolator due to non charging issues we now have another proBLEM that just came up. Now the vehicle will not start unless we connect the 3 cables to the center contact of the isolator.... There seems to be a large solenoid (6 contact) right below the isolator, and a couple smaller (auto) type solenoids. The draw is so much that no clicking, nor even generator, or even lights and buzzers will work unless all cables are connected to center contacts of the isolator when normally they are split between the 3 contacts with alternator being the middle. I took to a battery shop were I buy batts and we swapped out the isolator with a like unit with exact same results. The solenoid (?) I'm questioning is very large with 6 contacts. My question is, if familiar with this unit (L10 cummins engine), is it a solenoid and where can I look for replacements? THX and Happy New Year!

[tylerdmoore]

It sounds like the "solenoid" you're referring to is the battery combiner....the unit that allows you to combine House & Coach batteries for starting when the Coach batts are low.

That said, first off, have you checked voltage at you starting batteries? If you starting (coach) batteries are charged, then that solenoid is not your issue. I'm thinking that in the process of the earlier repairs that some wires may have been re installed incorrectly.

[c3idotnet]

Thx for the response... It's funny, they replaced the inverter before I nhad the shocks and bags replaced and it ran fine for a couple hours with some off time of about 3 weeks then when I picked it up and drove home (20 mins), stopping at kfc it wouldn't start even with all batts switch engaged. They came out and assisted me but the only way it would start is like I posted. It does seem weird that a black and red cable (auto type it appears) is on same side of that solenoid? coming from somewhere and if I didn't know better black and red never should be together... (from my electronics ...

THX! I will look more into it. A 6 pole does sound like a switch for the batts though?

[Mike Canter]

It would appear to me that IF you know the chassis batteries are fully charged and it will not turn over then you are troubleshooting the wrong end. It is NOT the charging end but is the supply end that is bad. Again if the chassis batteries are fully charged and you joined those cables together on the isolator then the only thing you are doing is putting the house batteries in parallel with the chassis batteries but that does help in troubleshooting the supply side of the engine batteries. You can check out that large relay by pressing the BATTERY BOOST switch on the dash. With the problem you are having now then it should start with that switch pushed. If it does then that relay is working OK.

So, if the motor starts when you tie the battery cables together on the isolator or push the BOOST switch indicates that the engine/chassis battery's positive or the negative cable has a dirty or bad connection at one end or the other. It also could be a the cable where it attaches to the battery. Just because they look clean doesn't mean that they are clean enough for high amps during the start cycle. I would get a battery brush and take off all the cable ends and clean them inside and out and the posts untill they shine and make sure the ground end of the negative where it attaches to the frame is good and clean and tight. Check all the crimps on the battery cable connectors. Usually if you try and start the motor from the chassis batteries only and you do it several times and hold the switch in the start position for 5 seconds then you can carefully feel all the main battery cables (both ends) with your hand looking for a connection that is warm or hot. Then clean and tighten that one.

If I am missing something in your problem then please re-explain the basic problem you are having.

1. Did you change the alternator, regulator and isolator for the same problem or a different problem.
2. Have you had you chassis batteries checked under load?
3. What voltage do you read on you chassis batteries right now?
4. What indication do you see when trying to start. Do you first get dash lights then when you hit start do they go out or stay on. If you turn on the headlights do they come on and what happens when you try and start the motor? do the headlights go off or stay on at the same brightness?

[MONGO MAN]

Quote:

Originally Posted by c3idotnet We have a 1991 monaco signature that we have put a lot of money in... After replacing the alternator, regulator and isolator due to non charging issues we now have another proBLEM that just came up. Now the vehicle will not start unless we connect the 3 cables to the center contact of the isolator.... There seems to be a large solenoid (6 contact) right below the isolator, and a couple smaller (auto) type solenoids. The draw is so much that no clicking, nor even generator, or even lights and buzzers will work unless all cables are connected to center contacts of the isolator when normally they are split between the 3 contacts with alternator being the middle. I took to a battery shop were I buy batts and we swapped out the isolator with a like unit with exact same results. The solenoid (?) I'm questioning is very large with 6 contacts. My question is, if familiar with this unit (L10 cummins engine), is it a solenoid and where can I look for replacements? THX and Happy New Year!

Best source for OEM replacement is MurCal Home Page (-Distributor)Trombetta Bear (brand name)-get the silver contact model - is OEM on Monaco & Winnebago- order the hardware package as the relay comes Naked with no nuts or lock washers

[Cayman09]

Quote:

Originally Posted by c3idotnet Thx for the response... It's funny, they replaced the inverter before I nhad the shocks and bags replaced and it ran fine for a couple hours with some off time of about 3 weeks then when I picked it up and drove home (20 mins), stopping at kfc it wouldn't start even with all batts switch engaged. They came out and assisted me but the only way it would start is like I posted. It does seem weird that a black and red cable (auto type it appears) is on same side of that solenoid? coming from somewhere and if I didn't know better black and red never should be together... (from my electronics ... THX! I will look more into it. A 6 pole does sound like a switch for the batts though?

Is it possible the shop used an arc welder without disconnecting the MH?

It would create all sorts of electrical damage. You say the shocks and bags were replaced... so I assume they redid the alignment and (At least on my MH!) changing the rear axle alignment involves unwelding washers and rewelding them after. My shop made sure to properly protect the MH when welding.

Just a thought!

[Dave78Chief]

Just a suggestion:
Given this is a 1991 coach, some pictures of the relays, solinoids, and wiring he is referring to might help in this case. I suspect 2000 and later coachs are just a bit different given the way technology changes. Just on a hunch his system is different from what most are familure with.

Dave

[c3idotnet]

here is a pic or 2 if i can upload them, of the relay? I m talking about, showing the ganging of the isolator... If I place them on each contact of the iso then I get nothing at the ignition, not even buzzing or lights.... BTW, no start with the batt boost engaged...



https://skydrive.live.com/#cid=54191...46B4EC97%21358

make sure the entire link is pasted. It shows the solenoid, the other solenoid wiht both black and red cable attached to same pole and the isolator...

[Mike Canter]

My guess looking those pictures is that the solenoid is your Battery Boost or sometimes called the Aux Start solenoid. Again, by joining all the cables together on one common post on the isolator is putting the Chassis and house batteries in parallel so your chassis side is now getting power from your house batteries.

My statement and questions are still the same. So, if the motor starts when you tie the battery cables together on the isolator indicates that the engine/chassis battery's positive or the negative cable has a dirty or bad connection at one end or the other. It also could be a the cable where it attaches to the battery. Just because they look clean doesn't mean that they are clean enough for high amps during the start cycle. I would get a battery brush and take off all the cable ends and clean them inside and out and the posts untill they shine and make sure the ground end of the negative where it attaches to the frame is good and clean and tight. Check all the crimps on the battery cable connectors. Usually if you try and start the motor from the chassis batteries only and you do it several times and hold the switch in the start position for 5 seconds then you can carefully feel all the main battery cables (both ends) with your hand looking for a connection that is warm or hot. Then clean and tighten that one.

1. Did you change the alternator, regulator and isolator for the same problem or a different problem.
2. Have you had you chassis batteries checked under load?
3. What voltage do you read on you chassis batteries right now?
4. What indication do you see when trying to start. Do you first get dash lights then when you hit start do they go out or stay on. If you turn on the headlights do they come on and what happens when you try and start the motor? do the headlights go off or stay on at the same brightness?

[Dunner]

A lot of those connections look like they haven't seen a wrench in a long time. It wouldn't hurt to at least loosen and tighten all of them.

[LonBoy]

The red thing is A BATTERY isolator(its being by passed) that seperates your batterys for charging and also not using the chassic battery for the house current .It all needs cleaned and the batterys need tested and in my opion the guys that hooked up your Inverter had to find a good strong 12volt source and when the found it they just added their wires and now the connections are not making good contact .
The isolator sholud have a wire on each terminal to work correctly. my guess is its bad so they just by passed it.

[lonestarace]

Here is another supplier of electrical components
Automotive and Heavy Duty 12 & 24 Volt DC Electrical Components

[Dave78Chief]

Picture 1 - Red box is a diode based battery isolator that distributes alternator charging voltage to chassis and coach battery systems. The solinoid above it would be a battery isolator used for Aux Start or Battery Boost function (there should be a switch on the dash with that lable on it that operates the solinoid). It cross connects chassis and coach battery systems so that coach battery can be "jumpered" to assist in engine starting (i.e. just like you have recabled the wiring to do). Originally, the cables were connected so that the red box was used to charge the coach battery when the engine was running. The isolation solinoid was just used to cross connect the chassis and coach batteries for Battery Boost. So, as far as your comment "BTW, no start with the batt boost engaged...", either that constant duty battery isolator solinoid is bad, or circuit controlling it is bad. Hard to tell from your picture if the small black wire (right side small post) is going to ground or if it is connected to the large post. Would determine if the Battery Boost switch provides 12VDC to the the lefts side small pin (orange wire) or if the switch provides a path to ground via the orange wire. Either way, for a 4 post isolator solinoid to energize, one of the small posts has to be ground the other would have 12VDC on it.

Now to your real issue - With all 3 cables connected as in the picture you currently have both the diode isolator (red box) and battery isolator solinoid shorted out (eliminated) from the system. If, this is the only way you can get the engine to start then that is saying you are using the coach batteries to start the engine (even if the chassis battery is good). Only way that would happen is if there is one cable from the starting battery going to an isolated stud and a second cable from the solinoid also going to that isolated stud. That first cable (chassis battery to isolated stud) is not making contact (bad connector at one or both ends). The isolated stud could even be a stud on a starter solinoid.

From your description, you did not provide a picture of the large 6 post solinoid (is larger than automotive looking relays). That is most likely a 200 amp coach battery disconnect solinoid that isolates the coach battery when in storage (Aux Battery or Coach Battery switch).

One final note, those automotive like relays are not standard starter solinoids. They are called 100 amp constant duty solinoids. A standard automotive starter solinoid will burn out if constally energized. The constant duty solinoids will not burn out if constantly energized.

Dave

[Mike Canter]

I think Dave and I are in perfect agreement as to what you have done and the results of what you have done. Like we said for now neither that solenoid or that isolator is the reason why your motor will not start. Like we have both said the only thing you have done is jumpered the house batteries to the starter so it starts from house battery power. You need to find out why you are not getting power from the chassis batteries to the starter motor terminal or if the ground cable for the chassis battery negative post to the frame is good. It could be a bad crimp where the connector fits on the positive or negative battery cable or a bad isolator stud/post on the positive battery cable.

What I suggest you do is to disconnect those two cables from that isolator stud and put them back where they should be. Then get either a 12 volt test lamp or a voltmeter and start checking for 12 volts along the positive battery cable from the chassis battery to the starter motor until you find there is no longer 12 volts. If that is all good then check the negative battery cable to ground from the chassis battery.