BAC Forum
General Boards => Technical Support => Topic started by: Brian Miller on December 08, 2024, 11:57:38 PM
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Gentleman, I’m trying to track down a start issue. Replaced starter a few months ago an we seemed to be good to go. Tried to head out on the
road and we got a no start situation again.
Pulled the solenoid in the battery bay checked continuity…. checked ok.
Pulled starter to bench test solenoid /starter. All checked ok.
I can jump starter….
Any thoughts or ideas would be greatly appreciated.
Brian
2000 Beaver Patriot
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My only guess is from my experience. If the transmission keypad is not reporting neutral with an "N" on the keypad, then the engine will not be allowed to start. The transmission MUST report a neutral status to the engine brain before the starter will engage. In my case, the problem was a blown fuse in the black clamshell box found just under the keypad. There are two fuses in that box.
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I’m not familiar with your particular era of rig, but on at least some models like mine there is a “Ford” solenoid in the “electric” bay, streetside foremost and beneath the driver, that commonly carbons up resulting in immobilizing resistance. It routes 12v via circuit breakers to basic chassis devices like you’d find on any highway vehicle. If you have a 2000 Patriot legend for that bay or can find one in BAC’s Coach Assist, you could test all related circuits with the ignition key on and off. Though less common, keyed ignitions can overheat or otherwise fail as well.
Joel
Example legend:
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Brian
The start signal from the ignition switch runs to the service bay where it is switched for front or rear start control that switch is known to have connection problems as it is exposed to road dirt and water at the rear of the service bay wall.
Or you wouldn't be the first one to leave that switch in the rear position causing a no crank condition at the key switch.
The start signal starts at the ignition switch ( these are older Chevrolet truck ignitions) and are known to develop intermittent problems at both the switch and the plug it plugs into .
It then goes to the Allison automatic transmission VIM box where it is controlled by a relay for neutral safety before it goes on to the rear of the coach
( it is to be noted that there are two 10 amp fuses inside the VIM module) without an N on the shift pad the neutral safety relay won't allow signal out to starter.
From the VIM module the start signal goes through a bulkhead connector ( large round connector ) located in or behind the front electrical bay cabinet below the drivers station ( that bay will collect water causing corrosion if there are any leaks in the front cap windshield area. ) check that connection as well for green connectors
From there the start signal travels to the rear service bay as explained above to the front rear selector switch ( known to go bad )
From the front rear selector switch it then goes to the primary solenoid mounted in the rear of the battery bay which controls the large solenoid on the starter.
The closest we can come to the right wiring diagram for a 2000 ( starter wiring ) Patriot is the 1996 Patriot wiring diagram page 18 will show you the wiring diagram for the start signal.
Hope this helps
Eric
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Brian,
Here is a picture of the hidden "starter solenoid" which is behind the battery box out of normal view. It is really a "trigger solenoid that activates the true starter solenoid mounted on the starter itself. Fred
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Just to keep everyone in the loop. All dash lights as well as the “N” neutral transmission light works as advertised. I recently replace the GM ignition switch replace the tumbler in the old one was shot. However, the Accessory position doesn’t work? (Don’t understand)….nor did the old old one but that’s on the back burner at this point.
I need to dig into the rear start switch as well as hidden solenoid.
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An intermittent ignition solenoid can cause the problem you are describing. Joel’s post above shows the location of the solenoid. It is a common failure point with these coaches. It is a Cole Hersee 85 amp continuous duty solenoid that can be found at Napa or any truck or auto parts store. Amazon is also another source if you can wait a few days. I used to carry a spare because of the failure rate of this solenoid, so by changing it now, you can eliminate it as a possibility of your problem. Hope this helps, good luck.
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Brian,
I agree with Frank. The 2 weakest links in the ignition circuit are the ignition solenoid and the ignition switch. Often times they get changed with off quality replacement products. The solenoid should be a Cole-Hersey continuous duty, and the ignition switch should be a Delco-Remy. The other issue to be cautious about is the "rear run switch. There was a time as I recall about 8 years when owners were using it an anti-theft device. The issue is the switch is back in a location where corrosion can develop inside of the switch. Activating the switch that was dormant for a long time can create a new situation. Now you have a compound problem. If you are comfortable using a test light, you can trace the 12volt power from the switch to the solenoid to the rear run switch to the trigger solenoid to the starter. Fred
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Ok, I did some searching behind the batteries. I did not fine another solenoid back there. However, there are 2 in tandem in the battery bay. The second is “Intellitec” solenoid?
What would this activate??
Thank you in advance
Brian
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It is probably your battery boost solenoid. Combines both sets of batteries to give you a boost when starting the motor home.
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That is the solenoid that turns the 12 volt power inside the coach. There is a switch at the entry door dash or consol. It is referred to as the salesman switch as the original purpose was to show off the interior to a prospect and then turn off the batteries when done. BTW that trigger solenoid is on the backside of the battery box. Fred
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Ok, I’ve crawled all around underneath and around the battery compartment. There is no solenoid that I can see behind the battery compartment. I did find another on the left outside the battery compartment. It’s hidden behind the left side battery box itself.
Could this be the solenoid I’m looking for??
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Brian
That is the right location.
There should be a. Sealed Relay in that area as well the relay is the ECM power relay.
The solenoid should be a regular shaped solenoid with two large terminals and two small terminals the start trigger signal to the starter is supplied by connecting the two large terminals.
A simple jumper wire across those two terminals should cause the starter to engage and verify you have the right solenoid.
Eric
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Brian once you have verified t the at you are working with the start trigger solenoid you can now verify the start signal to it.
The solenoid is an isolated ground solenoid meaning the coil inside is isolated from ground
One of the lead wires has to provide ground and the other should have a start signal whether it is from the rear run / start switch or the front ignition switch
In either case the start signal comes through that rear run switch. You should be able to diagnose this with a test light.
The most likely cause of an intermittent no start in this area would be either a lose of ground for the solenoid trigger coil or a bad connection in that rear run switch.
Erc
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Gentleman,
Good evening, after a long search I found the culprit solenoid. It was on the left hand side of the battery compartment between the sealed relay as well as the ecm hidden behind the transmission service hose. (The wx has been demanding outside ) I had enough cable to relocate to another location.
Good news! Job complete…..started right up this morning @ 19degrees.
Thank you all for your expertise and guidance.
Merry Christmas and Happy new year!
Brian
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19 degrees??? Where the heck are you? It's 71 degrees here right now at 5:23 pm with no wind and has been partly cloudy all day. Please remind me never to go where you are, especially in December.
Glad you got it fixed.
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Brian
Glad to hear your up and running again .
Have a Merry Christmas
Eric