| Air Bag Suspension relays and diodes... [message #130408] |
Thu, 16 June 2011 02:15  |
amdgmcman
Messages: 76
Registered: April 2007
Location: Long Beach, CA
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Greetings,
Who can tell me where the relays and diodes are located for the stock air bag suspension on my 78 Royale Coachman center kitchen floorplan model?
Thanks,
AMDGMCMan
Alan M DeLuccio
78 Royale with
Coachmen,Center Kitchen Floorplan
09 Harley Davidson Street Glide
65 Corvair Monza Convertible
96 RAV4 2 door Manual 4WD
Long Beach, CA
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| Re: Air Bag Suspension relays and diodes... [message #130413 is a reply to message #130408] |
Thu, 16 June 2011 07:04  |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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| Quote: |
....Who can tell me where the relays and diodes are located for the stock air bag suspension on my 78 Royale Coachman center kitchen floorplan model?.....
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I can. Do you have ElectroLevel or ElectroLevel II?
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: Air Bag Suspension relays and diodes... [message #130425 is a reply to message #130423] |
Thu, 16 June 2011 13:33 |
jim kanomata
Messages: 257
Registered: March 2007
Location: fremont,ca
Karma: 12
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77-78 like all the other years can be off as some were registered depending on where ir went to be completed.
Serial # is the best way to tell.
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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| Re: Air Bag Suspension relays and diodes... [message #130442 is a reply to message #130423] |
Thu, 16 June 2011 19:23 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
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| Dan Borlase wrote on Thu, 16 June 2011 10:34 |
John...educate me...since his coach is a 78...would'nt the suspention be El. II ?
Dan
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The last GM "upgrade" to the air system, The Electro-Level 2 system, was only installed in the LAST part of the 1978 model year. Early 1978 coaches still had the Electro-Level (1) system.
BUT...
The Diodes should be in the same location on either system.... I think they are under or near the switches on the driver's side panel. (I haven't had to work on them...)
I am fairly sure that the relays on both systems are near or on the air pump(s). For EL (1 or 2) systems, the Air pump(s) are normally on the floor, under "something," on the driver's side, somewhere near the rear wheel well.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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| Re: Air Bag Suspension relays and diodes... [message #130465 is a reply to message #130423] |
Thu, 16 June 2011 20:33 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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| Quote: |
..educate me...since his coach is a 78...would'nt the suspention be El. II ?
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Dan, ElectroLevel II was the last generation of rear suspension. It was implemented mid-run of the '78's. Bill Bryant has done some research and perhaps he will chime in.
As far as the diodes go, they are all in the wiring harness at the switch panel in front. All the relays are in the back in the compressor area. It depends if it's ElectroLevel or ElectroLevel II as to exactly where in the rear they are located.
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: Air Bag Suspension relays and diodes... [message #130673 is a reply to message #130465] |
Fri, 17 June 2011 22:04 |
amdgmcman
Messages: 76
Registered: April 2007
Location: Long Beach, CA
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The compressors are located under the wardrobe closet to the rear of the bathroom on the drivers side.
AMDGMCMan
Alan M DeLuccio
78 Royale with
Coachmen,Center Kitchen Floorplan
09 Harley Davidson Street Glide
65 Corvair Monza Convertible
96 RAV4 2 door Manual 4WD
Long Beach, CA
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| Re: Air Bag Suspension relays and diodes... [message #130738 is a reply to message #130673] |
Sat, 18 June 2011 11:35 |
amdgmcman
Messages: 76
Registered: April 2007
Location: Long Beach, CA
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How can I tell if it's ElectroLevel or ElectroLevel II?
AMDGMCMan
Alan M DeLuccio
78 Royale with
Coachmen,Center Kitchen Floorplan
09 Harley Davidson Street Glide
65 Corvair Monza Convertible
96 RAV4 2 door Manual 4WD
Long Beach, CA
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| Re: Air Bag Suspension relays and diodes... [message #130739 is a reply to message #130738] |
Sat, 18 June 2011 11:39 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
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| amdgmcman wrote on Sat, 18 June 2011 09:35 |
How can I tell if it's ElectroLevel or ElectroLevel II?
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As you said "compressors" (as in more than one) you would have an EL2.
The Electro-Level only has one pump (compressor) and a bunch of solenoids.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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| Re: Air Bag Suspension relays and diodes... [message #130747 is a reply to message #130739] |
Sat, 18 June 2011 12:40 |
amdgmcman
Messages: 76
Registered: April 2007
Location: Long Beach, CA
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Ok ... I have an ElectroLevel II ... are the diodes in front to the left of the drivers seat near the switches & the relays at the compressors at the rear?
AMDGMCMan
Alan M DeLuccio
78 Royale with
Coachmen,Center Kitchen Floorplan
09 Harley Davidson Street Glide
65 Corvair Monza Convertible
96 RAV4 2 door Manual 4WD
Long Beach, CA
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| Re: Air Bag Suspension relays and diodes... [message #130748 is a reply to message #130747] |
Sat, 18 June 2011 13:02 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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The diodes for both are located in the wiring harness at the switches next to the driver. I doubt if there is a problem with the diodes. It's more common to be switches or connectors.
ElectroLevel has one compressor ,an air tank & leveling valves. Electrolevel II has two small compressors and electronic level sensors.
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: Air Bag Suspension relays and diodes... [message #130782 is a reply to message #130747] |
Sat, 18 June 2011 20:00 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
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| amdgmcman wrote on Sat, 18 June 2011 10:40 |
Ok ... I have an ElectroLevel II ... are the diodes in front to the left of the drivers seat near the switches & the relays at the compressors at the rear?
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YES.
Like John has said your problems are more likely to be "switches or connectors." than diodes and relays. (but as they are over 30 years old....)
I have had two problems with mine, one was a half disconnected connector and the other was bad seals on the height sensors. They would get wet and try and raise (pump) and lower (vent) at the same time... even when in hold.
A note on EL2 trouble shooting, there is a large connector near the pumps that will take the sensors totally out of the circuit. Just unplug it and you should have manual control.... if you do not... fix that first, before replugging the sensors back in.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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| Re: Air Bag Suspension relays and diodes... [message #130785 is a reply to message #130782] |
Sat, 18 June 2011 20:11 |
amdgmcman
Messages: 76
Registered: April 2007
Location: Long Beach, CA
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I have the 78 Royale Coachman Center kitchen floorplan with a ELll suspension. My dad bought it in 2001 from a gentleman that upgraded the coach in 1996-97.
When we first got the Royale the suspension worked great. Within the last few years it blows 30 amp fuses every time you level the coach. I have been buying Harbor Freight fuses, so maybe the fact they are so cheap is the reason. I just ordered some good quality 30A glass units on Amazon I expect to receive in a couple of days … I’ll see if they make a difference. I took it to Miguel at MGM a couple of years ago, (2009),before I went on a 6200 mile trip across the US, and he suggested that the PO installed heavy duty stabilizers on the front and rear of the coach that is pulling against the suspension thus working it harder. He checked the compressors and said they were fine. The fuses are extremely hot when they blow. I just keep replacing the burnt fuse and continue leveling. I’m always running the engine when leveling, and I have no other electric issues. It usually takes 2-3 blown fuses to level the coach. The fuses rarely blow when using the auto-level feature when driving, but often when running the compressors for an extended time like when leveling the coach at a campground or other uneven surface. If I raise one side at a time, the compressor runs faster and it DOES NOT blow a fuse .
Thanks,
AMDGMCMan
Alan M DeLuccio
78 Royale with
Coachmen,Center Kitchen Floorplan
09 Harley Davidson Street Glide
65 Corvair Monza Convertible
96 RAV4 2 door Manual 4WD
Long Beach, CA
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| Re: Air Bag Suspension relays and diodes... [message #130788 is a reply to message #130785] |
Sat, 18 June 2011 20:21 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
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| amdgmcman wrote on Sat, 18 June 2011 18:11 |
... If I raise one side at a time, the compressor runs faster and it DOES NOT blow a fuse.
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I would suspect a ground problem. Clean and inspect them....
Also a good upgrade is to run "stiff" power to the relays so the pumps get as close to full voltage as possible. That should reduce the amp draw.
Somewhere there is a handout with notes on all the systems... it shows this upgrade. If no one else posts a link, I'll look for it when I have time, I have to go to work soon.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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| Re: Air Bag Suspension relays and diodes... [message #130789 is a reply to message #130788] |
Sat, 18 June 2011 20:46 |
Dennis S
Messages: 3046
Registered: November 2005
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| Mike Miller wrote on Sat, 18 June 2011 20:21 |
| amdgmcman wrote on Sat, 18 June 2011 18:11 |
... If I raise one side at a time, the compressor runs faster and it DOES NOT blow a fuse.
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I would suspect a ground problem. Clean and inspect them....
Also a good upgrade is to run "stiff" power to the relays so the pumps get as close to full voltage as possible. That should reduce the amp draw.
Somewhere there is a handout with notes on all the systems... it shows this upgrade. If no one else posts a link, I'll look for it when I have time, I have to go to work soon.
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Maybe this one...
http://www.gmcws.org/Tech/dsimmons/air_suspension/air-suspension-system.html
Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: Air Bag Suspension relays and diodes... [message #130794 is a reply to message #130785] |
Sat, 18 June 2011 21:23 |
Don A
Messages: 895
Registered: October 2008
Location: Dallas, TX
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I'm guessing Miguel is right, the "heavy duty stabilizers" (sway bars?" on the front and rear are trying to equalize the pressure side to side while the bags are trying to change it?
Try disconnecting one end of the rear bar(s) and see if that doesn't solve your problem.
Don Adams Dallas, TX
'76 26' Glenbrook, '90 Sidekick
rebuilt by R Archer, powered by J Bounds, Koba
[IMG]http://www.gmcmhphotos.com/photos/data/6109/G2.jpg[/IMG]
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| Re: Air Bag Suspension relays and diodes... [message #130802 is a reply to message #130785] |
Sat, 18 June 2011 22:52 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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| Quote: |
.....If I raise one side at a time, the compressor runs faster and it DOES NOT blow a fuse ......
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The system was not designed to run both compressors for an extended amount of time. The power wire is a small one that runs from the fuse panel to the compressors at the rear wheelhouse. A long run for a small wire to run two high current compressors. The voltage drop in the wire causes the amperage to skyrocket. Run a larger wire or do what you have discovered and just run one at a time.
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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