Coach/chassis solenoids.

[Wakesupremo]

I have an issue thats been discussed on here before but not really answered. I have to turn on the chassis switch at the coach steps to get power to the ignition switch. This is obviously not correct but, this also has happened since I disconnected the botched in fridge circuit to these solenoids, I have the wiring diagram to these solenoids and, as far as i can tell, its correct.where should the ignition switch get its power from?

 

[Chuck v]

Chassis wiring is based on the platform that the coach-maker (Gulf Stream) purchased as a rolling basis on which to build the "house" portion. On my 2007Tour Master, I referred to the Freightliner manuals for guidance. The chassis was made in 2006, for instance.

What is the year and make of your underlying chassis? Remember, the chassis year my be one or more years earlier than the completion date of your final vehicle...

Chuck

 

[Wakesupremo]

Hi again Chuck. I have absolutely no idea. The motorhome is 1989 so I suspect it to be from that timeframe. However, the twin solenoid set up is obviously not part of the original electrical system and I think that has also been 'played' with.
If you look back to my previous pics of my set up there is also another solenoid in between the chassis/ coach solenoids. I think,(will verify later today), that theres a thick red wire on the right side terminal of that third solenoid which could be the ignition feed. That will only get power when the chassis solenoid is energised and latched on. If I move that to the power side of the chassis solenoid it should work.

 

[Wakesupremo]

I have now checked the wire in question. That goes to a 40 amp breaker which is labelled TV amp so I don't think thats the answer. I noticed that when I switch the chassis switch at the step and turn the ignition key to on, not crank, the coach led comes on as well!!! Lots of mysterious bits going on!!

 

[Chuck v]

Lets start with the basics: What year is on your title/registration document? What manufacturer shows there? In another of your threads you said that your unit is a 1989 Gulfstream 8272 -- that unit most likely has a GM and a 454 cu in gas V8, or an Oshkosh chassis with the 460 Ford.

The third solenoid in the photos on the other threads is very likely part of the BIRD circuitry that allows all battery banks to charge off the engine alternator when it is being driven by a running engine...

Be cautious about just changing the wiring because you "think" it might help -- please have a basis of how things work and are intended before further hacking the wiring of an old vehicle. If you loose it in a fire, you will have very much more repair to do if it is even possible after such an event. Best of luck, and proceed carefully !!

 

[Chuck v]

If your chassis happens to be the GM P30 series, this link has a large document that may be useful. Not much specific on the wiring, as much of the added electrical system would have been customized by the coach-builder (in your case Gulf Stream...)

https://www.gmcmi.com/wp-content/uploads/2014/05/P30-Chassis-Manual.pdf

 

[Wakesupremo]

Hi again and, yes, its a Chevrolet P30 base. As I said before, I know that the solenoids that I'm talking about are not original to the chassis. I'm also pretty confident when saying that I shouldn't have to walk to the coach steps to put the chassis battery in circuit to run the engine. I can't find any documents to say where the original ignition switch would get its power from but i'm convinced that its not via that switch, however, I'm also convinced that the solenoid circuit is correct. Obviously this has been 'played with' by previous owners but, I want it to be correct.

 

[Chuck v]

Correct would be best -- you just need to find the original configuration information, which might be a challenge after all these years. Maybe you can find another similar coach whose owner can help you trace things on their coach. You can try contacting Gulfstream and see if they have any diagrams in their archives that can help.

Until then, be careful with any changes that you decide to try just because they seem to make sense to you without proof of correctness. Better to live with a functional situation that is stable and "works, but with quirks" than to damage something. You seem to be electrically aware and have some experience, so you may find a way to get the functionality you want if you can trace what you have now fully and accurately...