Looking for wiring diagram in 1996 Beaver Monterey

[Peter Mann]

I've rescued a 1996 beaver from the crusher.  My biggest issue right now is chasing down some electrical gremlins, engine starts and runs, coach drives, but it has issues (some gauges not working, occasional dead dash, phantom 8V on the system sometimes).  I pulled all the documents in the technical library for the electrical diagrams and most of them are about the peripheral items (radio, AC, etc.) Does anyone have a wiring diagram for this coach, or something close enough to help?

Thank you

[Carl Boger]

Look under the members only tab and then go to Coach assist.  There are a few wiring diagrams for 96 coaches one being a Monterey.  This will just be a basic diagram as each coach has a few custom features.


I have found it useful to pull the two main plugs that connect to the wiring harnesses apart and to clean up all the pins good with welding tip cleaners and then contact cleaner from a spray can. I then put dielectric grease around the cases and put the plugs back together and zip tie them tight.   I have found that this fixes a lot of gremlins.  Hopefully this will help you getting yours back on the road

[Peter Mann]

Yep, those are the ones I already downloaded.  Unfortunately only two of them, 97042C1 and 95165C1 have the type of information I'm looking for and 97042C1 is only a partial shot of the full drawing.  Other coaches (96 marques, 96 patriot, 96 safari) all have much more complete diagrams so I was hopeful.  So-far it looks like there is some cross over between the models so I am using the others as a starting point.

When you say the two main plugs are you referring to the ECM plug (large square on the passenger side of the engine and attached to the ECM) and the round plug in the circuit bay on the exterior driver side up front?  I'm still digging around this thing and trying to figure out where everything is. those are the two I have found so far that are "large" most everything else is a basic blade style connector.

[Eric Maclean]

Peter
Most of the dash gauges are not ECM driven , they are analog gauges with sending units . the dash uses teleglex gauges .
That said the tach and speedo get their signal from the ECM.
You haven't described your electrical issues in detail yet .
The dash in these coaches are wired with many daisy chained ground terminals , all the dash gauges use crimp on ring terminals which are connected to threaded terminals with nuts these nuts have a bad habit of coming loose creating intermittent gauge operation ( gremlins)
The fuel gauge sending units is mounted on the driver's side of the fuel tank directly behind the tire the connections there get dirty and corroded causing fuel gauge issues.
The connections Carl speak of are the main harnesses running from the rear of the coach to the electrical bay and dash you will find them either in the top left corner of the electrical bay or behind it out side of the electrical bay box. Those connections have a habit of getting loose or corroded sometimes the windshield or front cap will leak and water will run into the electrical bay box creating issues over time.

Let us know what your issues are and we'll see if anyone else has chased this down before and may have some insight.

Eric

[Peter Mann]

Eric,
the problems are many, electrical in nature, and I suspect a mix of related and not. The wiring diagram was a place to start, without taking up to much of the forum's time; but here is a list, in no particular order:

1. No gauges and no start on occasion, it has only done this twice out of the 30-40 starts I have done.  the dash seems to have some power as I can get the gen start button to work, but I could also see something like that being on a different set of circuits than ignition.  It acts like the power (or ground, I don't know how the relays are wired yet) to the ignition switch is not working. It will come back on without warning or seeming like anything changed.   For example, I put the coach down off it's jacks and it came back
2. Leveling system intermittent function on the right rear, I suspect that a switch change or clean is all that is needed there, rear controls seem to work
3. Rear Hobbs meter is always running when chassis battery is connected.
4. dash oil pressure gauge shows between 0 and 5 psi while running (this should shut the engine off as I believe one of the ECM feeds is oil pressure) not sure what the actual oil pressure is, see next issue
5. Rear oil pressure gauge is always lit red and shows between 60-100 while running.  I have just been going with the average between the two for now
6. Fuel tank level gauge shows pegged off the gauge full most of the time, with the occasional dip to just full
7. Tach shows 1000 rpms when not running, then drops down to a more reasonable 700 at idle and 1500-2000 when running
8. Coolant temp gauge has yet to move, haven't really warmed it up much so this may be a non issue
9. intermittent 8V on the isolator alternator post and the coach post when not running.  I don't have any coach batteries in this yet, just chassis batteries.  This may be the reason for the Hobbs meter running as the notes in the electrical diagram show it connected here. Other times it shows 0V at the coach and alternator when not running.
10. When I turn the key to start (when not experiencing problem #1) the start boost solenoid activates and stays on it't warm to the touch after 10-15 minutes, and I never hear it click off. I'm not sure where the button / switch for boost is, I suspect its on the left side but all six of those buttons have lost their white writing
11.  Sometimes the pre-heat light will come on after starting for about 5 minutes then turn back off.  It doesn't come on before starting, or during starting, just about 30 seconds after.
12.  Sometimes the ASC solar has a red led showing, sometimes none. doesn't seem to be related to sun exposure, as it will have the light on when I am looking at something back there, I'll walk up front to check the gauges for example, then walk back and it's off. it's been low enough on my list I have never investigated it further.
13 turn signals work, but no click-clack just the lights on the dash and outside. Might just change the flasher relays to new ones, old might be muted with dust etc.

I haven't jumped into any of the other systems yet like 12v appliances, creature comforts, 115V, shore power, plumbing etc. Getting it reliable enough to feel like traveling more than a half mile loop will be step one. I'll probably break all of these out into individual posts as I start to tackle them.

Thanks

[Eric Maclean]

Ok Peter
I'll try to work through this with you
1)   no dash gauges and or no start condition
This is not an uncommon fault it is usually caused by the ignition solenoid located in the electrical bay being intermittent or faulty.
This solenoid is an 85 amp continuous duty solenoid which controls the ignition power to all the ignition operated functions it should pass 12 volts to the left hand buss bar with the ignition turned on ( that buss bar is all ignition feed circuit breakers.

2)
The leveling system may be as you say a bad switch or possibly a wiring connection .
( Which system do you have  RVA or SMC )

3)
rear hour meter runs all the time the battery is connected .
The hour meter should only run with the ignition turned on this problem and your rear run cabinet gauge lights may be the same problem as those lights should be the same way this is likely the wiring right at the rear run / service panel check it against the wiring diagrams for a wire which is in the wrong location .

4)
Oil pressure gauges don't read the same.
On these coaches the oil pressure gauges don't share information with the engine ECM ( the ECM has its own oil pressure sensor)
On your coach on the right hand frame rail beside the engine you will find an oil line with a tee and two oil pressure sending units screwed into it
These are the oil pressure sending units one for the dash gauge the other for the service bay gauge ( I'd replace both you can get them from almost any parts house )

5)
The rear oil pressure gauge is always lite up indicates the circuit is being bad fed possibly again check the wiring on the back of the service bay panel for inappropriate wiring.

6)
Fuel gauge pegged
This is most likely a bad connection at the sending units as mentioned in my last post ( clean those connections and try it again )

7)
The Tach at 1000 rpm when not running
For these gauges that is normal or acceptable however if they fluctuate or bounce while the engine is running the problem is most likely poor ground to the gauge.


Coolant temp gauge doesn't move off cold
This could be one of several things number one the engine has to warm up this can take as long as 30 minutes depending on ambient temperature
You could also have a thermostat or sending units failure.

9)
8 volts at the isolator chassis battery side I assume
This is likely the solar panel input   you can verify this by covering the solar panel/s with a blanket and rechecking for voltage

10)
The boost solenoid comes on with ignition and gets warm
The boost solenoid in your coach will be a White Rodgers continuous duty solenoid mounted at the isolator panel the control switch for it should be the center one in the rear row of switches on the driver left console it will be the momentary switch
Your coach may be wired differently to allow boost operation on ignition operation to aid in start up ( your going to have to look into that one)

11)
Engine preheat light comes on after startup
This is normal as the ECM will cycle the intake heater for a period of time during cold weather start up to aid in engine warm up
( The period of time it does this varys with the engine temp ( colder =longer)

12)
Solar red light
I'm not familiar with your particular solar charge controller however these coaches usually had two solar panels one for the chassis battery which had no charge controller and was so small it was almost inconsequential and a larger one which charged the coach battery bank it two was not very large and was intended only to top up a static battery bank when not in use.
The red light may be a fault light or a charge indicator either way it would be best no have a coach battery in the system before looking into that.

13)
Turn signals ake no noise
This is normal as the flasher unit is mounted in the electrical service bay you won't hear it anyway.
You could install a set of beepers on the dash indicators if you want an audio output

This should give you a good starting point .
My advice would be to at least install a battery on the house battery bank before going any further as the inverter will. Set faults if powered up without a battery bank to monitor or charge

Hope some of this helps
Eric

[Peter Mann]

Eric,

This is solid gold!! Thank you.  A few follow up questions and answers to yours

1. Is the electrical bay the compartment on the outside driver side front of the coach?  I had been looking under the bed for the relay (where the boost relay is located) so this would explain why I couldn't find it.
2. I have an RVA, I checked and they have switches available, and it looks like a fairly basic switch that I could get from another parts house.  I'll get one on order and swap it out.
3. I agree with the improperly connected wire, right now it is connected to the alternator post on the battery isolator.  I suspect that my isolator may be bad and that's the source of the 8V, this would also possible run the meter and effect the oil gauge
4. Great information regarding the oil pressure gauges, I thought they were pulling ECM information.  I'll hunt down the sending units and swap those out
5. same as #3 suspected isolator or bad wiring
6. I'll track that connecting down and clean it off
7. That's and easy fix, ignore it.  It seems to operate fine while running, just when engine off is it strange
8. I agree, big motor and cold weather, may not have gotten it warm enough yet
9. I'll disconnect the solar and check, also possible isolator issue, so I'll chase all of those
10. thanks for letting me know what switch, I'll move it back and fourth for a bit and see, everything needs a cleaning anyways and I'll be pulling some of that side apart to check and clean the levelers
11.  Another easy fix, ignore it, let it do its thing
12.  I think I did see two panels up there one big and one small, I'll try and track them down and see where they land.  Might replace all of that one day
13.  Another easy fix, didn't know they were in that bay, might add beepers, or just pay attention to the dash like my other old truck.

Great information on the coach battery and the inverter.  I've never plugged it into 115, or tried any 115 circuits, so I may be safe there.  I may just throw one battery in there to provide voltage for testing etc. before I buy four new ones.  I'm sure there will be more things to track down

For now you have given me some great things to look for and I have my work cut out for the next week or so.

Thanks again,
Peter

[Eric Maclean]

Peter
Yes the electrical bag is the cargo door below the drivers station. The first one on the driver's side accessed from out side.

[Peter Mann]

yep, thanks, I had in my mind that was for 12V coach living space(lights, appliances, etc.) I found a picture of a drawing that is usually inside the door that has some good descriptions of the connections (although mine is laid out different, but it's a start)

[Steve Huber Co-Admin]

Peter,
In case you haven't found them, the 96 Monterey wiring diagrams we have are located in Coach Assist; Factory Brochures; Brochures for almost all Beaver Coaches; Safari Motor Coach Corporation (1994-2001); 1996 Monterey Schematics. While it doesn't have a diagram of the front electrical bay layout, the 1996 Patriot Schematic file does have one and it should be pretty much the same.
Hope this helps, Steve

[Peter Mann]

Yep, I started with the 1996 wiring diagrams in the Tech section, but as you noted, they don't have much of what I was looking for. Good to know on the 1996 Patriot, I have been using that one and marking it up as I go because it seemed fairly close, it is also much more complete.