Ck Sup? Check suspension light displayed.

[Cody Kilkenny]

Good morning to everyone! I have recently purchased a 99 Explorer Limited AWD, 5L with ARC. I was hoping that I could some pointers on the Auto Ride Control system. The CK SUP light is on and I'm a little stumped on what to check first and still unsure as to the location of the air compressor? Any thoughts on the matter would be greatly appreciated!!

 

[MrQ]

There is a switch in the back panel that turns the ARC off and on, the compressor is located underneath the cargo area next to the spare tire. Is the compressor turning on? If not I'd check the fuse and relay under the hood in the distribution box.

It is very likely if the compressor is running all the time that the shocks have failed. The shocks on these units are specialized with an electronic solenoid that soften or harden the shocks. They are incredibly expensive and difficult to find. Most people ditch them in favor of standard shocks. See the link below.

Remove ARC

 

[massacre]

Wow haha
With your screen name and post count, I thought those were your initials and you were saying “sup” (“what’s up”) to everyone.
Sorry I can’t help but welcome to the site!

 

[Turdle]

Wow haha
With your screen name and post count, I thought those were your initials and you were saying “sup” (“what’s up”) to everyone.
Sorry I can’t help but welcome to the site!

and I also. I took the liberty of editing the thread title for clarity.

 

[Cody Kilkenny]

Thanks for the sound advice and warm welcome, In hindsight I can see the confusion with the title.....my bad Haha. In regards to forums and arc im "green" as they would say. I will check that out when I get home from work and I will get back to you. Also I have another topic or "thread"..... I think? I have a sunroof and overhead console the buttons to turn the map lights on dont work but if you open the doors the map lights come on and if you push the light button while the doors are open the lights will cycle on and off. I'm kinda stumped on this issue as well and if I should be making a second thread please let me know. Thanks again and will check back soon!

 

[MrQ]

There are two different ways to activate those lights. They double as the overhead lights when the doors are opened and by the dimmer dial, but can also be activated as "map lights" when pressed, which gives you a slightly brighter output.

I would look at the switches for the buttons. I believe in the later years they used microswitches on the display board versus mechanical ones. Check to see nothing is broken or you have a bad trace or bad solder joint.

 

[1998Exp]

It is very likely if the compressor is running all the time that the shocks have failed. The shocks on these units are specialized with an electronic solenoid that soften or harden the shocks. They are incredibly expensive and difficult to find. Most people ditch them in favor of standard shocks. See the link below.

Remove ARC

The air shocks are not that expensive and not that hard to find. Monroe makes them, and you will find them on Rock Auto for about $70 a piece. Those will not include the solenoid that stiffens/softens the ride, but this function is rarely needed anyway. The +1" height adjustment will still work when you switch to the "Off Road" position.

 

[CDW6212R]

The 99-01 ARC systems were rear shock only, and optional on any 4dr Explorer, no longer standard on anything.

eBay has the OEM replacement rear shocks for about $79.95 a pair; Ford OEM Both Rear Air Shocks AT688 & AT686G NEW Bulk | eBay

If the air compressor is allowed to run constantly, it will kill it. Air leaks are most common, at the solenoid connections or the shock connection. There are seals in those, either rubber o-rings or plastic washers(shock connection), replaceable items.

Make sure that the rear height sensor is all intact and connected properly. It's a complicated assembly and fragile, plus corrosion in the joints will create wear and slop. Lubricate those joints too.

For 99-01's there is no off road switch option, it's only a rear leveling system. It's great for hauling any loads.

 

[MrQ]

The 99-01 ARC systems were rear shock only, and optional on any 4dr Explorer, no longer standard on anything.

eBay has the OEM replacement rear shocks for about $79.95 a pair; Ford OEM Both Rear Air Shocks AT688 & AT686G NEW Bulk | eBay

If the air compressor is allowed to run constantly, it will kill it. Air leaks are most common, at the solenoid connections or the shock connection. There are seals in those, either rubber o-rings or plastic washers(shock connection), replaceable items.

Make sure that the rear height sensor is all intact and connected properly. It's a complicated assembly and fragile, plus corrosion in the joints will create wear and slop. Lubricate those joints too.

For 99-01's there is no off road switch option, it's only a rear leveling system. It's great for hauling any loads.

View attachment 163677

View attachment 163678

Interesting I wasn't aware those existed. Do those have the sensors as well or they just strictly air shocks?

 

[CDW6212R]

Interesting I wasn't aware those existed. Do those have the sensors as well or they just strictly air shocks?

Only ARC shocks with air bladders have been made since about 1999. I don't know why Ford did away with the firmness electrical valving feature, but I think it happened about the same time when the 99-01 system began.

I have a friend who has owned many Turbo Coupes, and we parted out two of them which his son wrecked. We saved the front pair of shocks from one of those, that's about when Ford began that shock valving feature. In those it was a three position function, firming the shocks a different amount. In the 95-98 Explorer, I believe it was simply one firm and one soft choice, by a switch at the top left of the radio bezel. 4WD's had their normal switch that controlled the ARC shocks, and the V8's had a unique "Off Road" switch that did just that.