BAC Forum

General Boards => Technical Support => Topic started by: John Brown on October 10, 2014, 04:30:44 PM

Title: 1988 Marquis-question about switch
Post by: John Brown on October 10, 2014, 04:30:44 PM

my new to me 88 Marquis 36' has a toggle switch to the right of the transmission shifter. It's has a beaver logo below and had writing above that has worn off.
Anyone know what this switch is for.

Thanks
John

Title: Re: 1988 Marquis-question about switch
Post by: Mark Beighley on October 10, 2014, 10:10:09 PM

Can you post a picture?  

Title: Re: 1988 Marquis-question about switch
Post by: Mark Beighley on October 11, 2014, 10:10:15 PM

Does this help?  Mine doesn't have the engine brake installed but if it was there would be a toggle.

Title: Re: 1988 Marquis-question about switch
Post by: John Brown on November 08, 2014, 07:16:27 AM

sorry it took so long but here's a picture. Any one know what this switch is for.

thanx
John

Title: Re: 1988 Marquis-question about switch
Post by: Edward Buker on November 08, 2014, 02:56:53 PM

John,

I wonder if it is engine preheat. The blocks on the older cats had a block heater in them that is I remember right was turned on by a 12V circuit powering a relay. If you have a way of seeing AC amps or DC amps in your coach you might see what kind of AC or DC load is drawn and that would provide some clues. I'm sure you checked things like lights, so I was looking at possibilities that do not result in anything obvious.

Later Ed

Title: Re: 1988 Marquis-question about switch
Post by: John Brown on November 08, 2014, 04:57:40 PM

Thx Ed. There's a switch on the dash for engine pre heat and I haven't noticed any lights turn on or off when I push the switch. When you push the switch it springs back when released so I'm not sure if that means it can only control certain things.  I haven't pushed it while driving because I'm concerned about what it controls and if it will cause any problems.

Title: Re: 1988 Marquis-question about switch
Post by: LaMonte Monnell on November 08, 2014, 05:02:36 PM

could it be a battery boost switch since it springs back off when released?

Title: Re: 1988 Marquis-question about switch
Post by: John Brown on November 08, 2014, 05:06:43 PM

Thx Lamonte, there is also a boost switch on the dash. I'm thinking it might have to do with transmission since it's so close to the shifter. Maybe an over drive switch?

John

Title: Re: 1988 Marquis-question about switch
Post by: Joel Ashley on November 08, 2014, 09:46:32 PM

I wouldn't think an overdrive button would be a momentary type.  If no one here helps, John, consider emailing the photo to BCS in Bend;  someone there probably knows what it's for.

I suppose this coach was before they started printing on the white wires, so John can't just remove the switchplate and check the wires under it for ID.

Joel

Title: Re: 1988 Marquis-question about switch
Post by: Edward Buker on November 09, 2014, 12:51:15 AM

There are not too many momentary switch uses on a dash. I had a momentary boost switch on an 89 Contessa and added a non momentary switch boost switch for charging. You could listen for the solenoid in the battery compartment while someone presses it to sort if that is the function. Possibly clearance light blinking. Generator start would be obvious.

Later Ed