BAC Forum
General Boards => Technical Support => Topic started by: Tom Chace on October 29, 2017, 04:10:38 PM
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Morning everyone,
I have a series of issues with my coach.
1. The Main would not start - I had the converter shut off during an unrelated job for a few weeks
2. I went chasing possible problems - didn't find it but managed to make the problem worse
3. I swapped the solenoid in the electric bay with a different one but didn't look closely enough
a. The original solenoid is insulated
b. The replacement was grounded
I think this was my second - Big mistake
4. My problem now is no power to the ignition OR drivers instrument panel at/through the ignition switch, no power.
5. I found that I popped the #5 fuse in the battery compartment so I replaced that
6. I tried to find the fuse to the instrument panel in the electric bay(top left of the fuses) and replaced that but no change - still no power to the instrument panel
My thoughts now are to FIX THE PRIMARY PROBLEM then replace the solenoid in the electric bay, replace the solenoid above the batteries--- this will not get me to the final solution because I have to find where the power is interrupted and by what fuse/module/relay. Once I have that I will address the starter.
I have myself in a situation that I need help with so I am asking for any help that is available from the group.
What do you think???
Tom Chace
1999 Beaver Monterey
3126b CAT
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Tom,
Do you have power to the ignition buss bar in the electrical bay when the key is on? In other words, is the ignition solenoid working.
Steve
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Tom, to get you started you need power to the ECM on connection J-1 wiring harness connector
going into the Engine ECM which is the connection to the rear on the ECM. What you are looking
For at this J-1 connector wiring harness red wire in lower left corner on connector or taking the
Connector loose with Allen wrench and removing connector for wiring harness same location
Lower left corner ( you are looking for Pin 70 which is the 12 Power for the ECM and ground
pins in middle on ECM connection next row up from bottom pin 53, 54, 56 ) not sure on one ground
pin but will look up when I return home. This will power up your ECM and should get you going.
Working away from the ECM knowing what wires will get you going you should look at broken power
Wire or fuse ground on relay. Dave Atherton Retired Cat Mechanic
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Steve,
No power
I fried my meter doing another test so I am on my way to getting a new one
Tom
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Tom,
Check to see if you have battery power on the input post of the solenoid (also should have it on the battery buss in electrical bay). If no power there, you probably have a blown fuse in the battery bay (one of the large high amperage ones). If you do have power on the input you probably have a bad solenoid. To be sure, turn the key on and see if you have 12V on one of the small solenoid terminals,. If so, bad solenoid.
Steve
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OK
Back from taking a break and playing in the ocean.
I will pick up the project on Tuesday as we are going to get nasty weather.
I plan on taking all steps outlined to try to get a response from the coach.
Thanks to all
Tom
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Hi All,
From my first message
I went chasing possible problems - didn't find it but managed to make the problem worse
3. I swapped the solenoid in the electric bay with a different one but didn't look closely enough
a. The original solenoid is insulated
b. The replacement was grounded
Would this mistake make me look for a popped fuse in the electric bay?
I tried the IG PWR top left but nothing changed
Tom
PS am following up on everyone's advice
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Update
The solenoid that I used to replace the starter solenoid was the same as what was originally in the coach - Insulated Cole Hersee 24117-BX
Now that the solenoid is shown to be correct I can chase down the original problem of not starting
After replacing the starter solenoid I tried to start the coach and popped the #5 fuse in the battery box
I am going to check the ECM on the Main as suggested and work back from there
Thanks to All
I will update as soon as possible
Tom
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Steve,
There are 2 solenoids in play here if I am reading correctly - One in the electric bay (Insulated) the other in the battery compartment which looks to be original and in need of replacement.
Bought a new meter - Problem 1 solved
I had the diode backwards - Problem 2 solved
Meter read 13+V in batteries, power on the input of the solenoid in the elect bay and power at the ignition switch.
With the meter in front of me - I turned the key to on and my voltage went away and no other power at the ignition switch.
I then put the meter on the solenoid in the elect bay - at the off position of the key --- I have power to the input then turning the key to on I have power to the input side but not to the exit side or to either of the small poles
I then switched out the solenoid to the Cole Hersee 42117 there was no change.
What I have at this point is
When I turn on the Ignition switch - no power and no start
Not sure if the solenoid (elect bay) is working or not
Could there be a fuse blown that controls the instrument panel? The top left 15 amp fuse labeled as IG Switch has power on both poles so is good.
Thank You
Tom
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Tom,
I don't think it is a fuse as you have power with key off. It sounds like you may have a shorted diode at the solenoid in the front electrical bay. Make sure the diode between the 2 small terminals on the solenoid is connected correctly. The band should be to your left (toward the battery buss) as you look at it. Also be sure it is not shorted. Remove one side of it and measure the resistance across it. Then reverse the meter leads and read it again. There should be a significant difference in resistance between the 2 readings. If not, replace the diode.
Battery power is supplied to the small terminals of the solenoid from from CB1 on the battery buss. From there it goes through the ignition switch to the solenoid terminal. If the diode is bad, CB1 may be tripping. It will reset when the load is off.
Steve
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Thank You Steve,
That is one issue resolved
I removed the diode and the power came back to the inst panel
I am about to be the proud owner of 50 diodes - soooo if anyone is in need of a diode or two send them my way.
Now -- with that issue gone
The coach is back to not starting - but I have power to the inst panel
Is the solenoid in the battery compartment also a starter solenoid???
Tom
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Tom,
The solenoid in the battery compartment is probably the "coach power or "salesman switch" It removes 12v from the coach when the coach power switch (normally near the entry door) is pressed. It reapplies power when the switch is pressed again.
When you say the coach doens't start, please describe more fully. Is the engine turning over? If not do you hear a click from the starter?, etc.
Thx, Steve
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Thanks Steve,
When trying to start
Turn the key to start position and nothing.
No clicks nothing
There doesn't seem to be any power (12V) going to the starter at all.
I did change out the rear (battery box) solenoid - that is a tough one to get to!
Tom
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Steve
You wrote:
(If you do have power on the input you probably have a bad solenoid. To be sure, turn the key on and see if you have 12V on one of the small solenoid terminals,. If so, bad solenoid.)
I do have 12 V on one of the small terminals as well as the other large pole of the solenoid when the key is in the on position - Is that what you were talking about?
Tom
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Tom,
With key on, you should have 12v on both large terminals and the small terminal nearest the battery buss (one closest to the band on the diode).
Steve
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Steve,
Yes that is what I have (less the solenoid for now )
Tom
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Tom,
With key on, is the transmission panel lit up? If not the ECU is not getting a neutral signal and engine will not start.
Steve
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Not only must the transmission shift panel be lighted, but also the gear selection must be neutral (N) for the engine to start.
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Steve/Dave
Thank you
Yes, the transmission panel shows N with key to the "ON" position
Tom
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OK
So I tried this a few days ago BUT wasn't focused on this as a likely source of the issue.
Went to the coach this morn after reading the latest posts and diligently made sure of neutral
From off I pressed neutral and held it turned key to on to start nothing
held the neutral and turned key from on to start 3 or 4 times when the engine started.
WOW do I hope that was the trick - the coach is now running and I have a small amount of details to cleanup.
Thank You ALL !!!
Tom & Pam
Headed for FLA!
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OK
I had the coach running this morning NOW nothing
I did drop a wire from that rear(battery box) solenoid and am not sure of where the wire goes - If anyone has a diagram - can you send it along.
It seems like the ECM or the starter ???? I am missing something but I need to get back to square 1 with the solenoid wire
Frustrated in Rhode Island
Tom
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Tom,
You may have an intermittent starter solenoid. Ignition switch seems OK based on your previous posts.
Steve
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Steve & Dave,
A long day at it - GRR
I have the starter working - even moved the RV so that I could reinstall the onan
The genesis of the problem was electric in nature - I believe since I rattled (gently) the ECM wire harness at the main.
I crawled all over the place to get to wires that haven't been touched since it was new trying to find loose/broken connections.
not going to bore you but the coach starts every time
I am going to get into the ECM a bit more and check it with a meter - check wires - clean up etc...
there could be some corrosion there ???
Thank You all so very much! I appreciate all of your help
Tom
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Steve,
I think that you are correct
I had the coach started this afternoon after:
Cleaned every ground, dielectric greased and re-installed
Checked the ECM - all looking almost brand new - very clean
When the engine was running the starter solenoid heated up?
I will get a new one and swap out.
The battery box solenoid doesn't seem to do anything - I couldn't find any numbers on the wires - very tight in there
Would you know of anyone that has a diagram of the wiring in the coach or is it available on line?
I thought the intermittent might be the trans but that doesn't seem to be the reason - I thought there might be a blown fuse/relay to the Allison ??? I read that from another post on BAC.
Tom Chace
1999 Beaver Montrey
300/330 3126b CAT