ARC unit re-location / removal

I have an issue involving that rack for the ride control also. I need the space for my sub box (had it my other 90 LX, which is now gone, but I just bought a 90 SC so I am dealing with this stupid rack.) Anyway, I took out the factory amp and left the clips for the bypass but tried to take out that rack and hit some snags. Anyone have any helpful hints or tricks to remove that thing? Or even relocating it temporarily since in time I looking to go to KYB or Koni down the road so I can keep the ARC but need space for my subs. Any one know of any issues or things to watch when removing/relocating the ride control components? And if I remove it completely now before I put in the new KYB, Konis, would it just stay in firm or auto or whatever position I leave it in before I disconnect it? Thanks Guys !! 1990 SC, White on Blue, 61k mi. So glad to be back !!

The rack is pinned at the top to the back deck on both ends/4 corners. It is hinged on one end and has releases on the other...I suspect you've figured that much out, but all 4 corner mounts require access from the top, under the rear deck carpet. Going in that direction may require removing the seat belt retractors, carpet and center brake light...not something I wanted to get into.

I released the pins on one end and cut the posts on the hinged end, leaving all four mounts in place so I could fit a sub box. I ganged the components into bundles and let them rest on the sub box. I eventually found another, shorter sub box that would fit with the tray in place so I reinstalled the tray and put the components and wiring back in their original locations.

Mine is a little ugly but here's my setup. Rear seat, 3rd brake light, Deck carpet, and seat belts need to come out. Really not that bad of job to do. If you notice in the far left, I removed the deck lid springs and redesigned the lift system with gas struts and 2 small brackets attached to each hinge. Layed down a couple layers of dynomat while I had the carpet out.

That tray took up a lot of space.

JJ

Thanks for the advice guys. I took some good info from both replies. I am still undecided about what I will actually do. Maybe I should just make my life easier and install KYB or Koni, and this way I can just remove the ARC all together. I prefer the firm ride anyway and once I change things up I can probably delete it.
I am looking to keep the subs that I have so I don't really want to look for diff subs so I will probably go with removing the ARC since at some point in time I won't need it anyway and it just seems like a lot of work to relocate it. Would I be wrong in thinking that If I remove the ARC now, then I should remain in "firm ride" mode once it is disconnected? I am curious to know what happens once the ARC is removed because if it then defaults to the firm ride, then I should be in the clear and can just put in the KYB later on and will have the clearance that I need now. Thanks guys !!

The shocks have mechanical valves that are rotated to one of two positions: normal or firm. The valves are rotated by electric actuators that sit on the top of each shock when installed. The default when assembled and with the ARC switch off is 'normal'. Based on one of the sensored inputs, the shocks are changed to firm until the input returns to normal and the shocks are put back on default. Moving the console switch to firm sets the shocks accordingly.

What they are set to if you remove the ARC module and/or sensors or actuators depends on the above. If you want them on firm, then use the console switch before removing/disconnecting other components.

Thanks so much for the input. I was pretty much thinking along those lines so you confirmed what I was thinking. I was hoping to work on this already but have been stumped by and am dealing with a low idle issue that is driving me nuts. But once I get the idle figured out I will then turn my attention back to the ARC. Not to jump ahead too much but I am thinking to leave it on firm like you said, then remove the ARC and leave it that way for a while. Eventually I am going to do KYBs and Eibach so at least removing the ARC and leaving itin firm will temporarily work for me until I get to do the KYBs etc. Any insight on if once I have it removed, left in firm, installed KYBs, I should be in the clear? Any other issues that you know of that I might run into? I am guessing to remove those actuators while I am there no? Thanks !!

JohnnyTbird said:

Any insight on if once I have it removed, left in firm, installed KYBs, I should be in the clear? Any other issues that you know of that I might run into? I am guessing to remove those actuators while I am there no?

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Depends on how far you want to go. The list includes:
- shocks
- actuators
- controller (also controls speed-sensitive steering)
- steering wheel sensor (part of speed-sensitive steering)
- pressure switch
- ARC lamp in dash cluster
- ARC switch in console
- harnesses

I prefer to keep ARC, so I don't have any experience with abandoning that system. It would seem that if you convert to KYBs, as an example, you can stop there if you like....everything else is just cleanup

I was thinking along the same lines too. Should be pretty much cleanup like you said after the swap out. Once I do get there I will probably just remove the Arc, install the KYBs, pull the ARC bulb on the control center and maybe the actuators. Of course as it was once said "when man make plan, God laughs" lol. So I will see how my "plan" goes once I get started. Thanks Again !!

Remember the ARC module also controls the Steering system too, with no bulb diagnostics will be a bit harder.

bowez said:

Remember the ARC module also controls the Steering system too, with no bulb diagnostics will be a bit harder.

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Right, speed-sensitive steering. (updated my reply above, thanks)

KMT said:

Right, speed-sensitive steering. (updated my reply above, thanks)

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I am glad you mentioned that about the speed sensitive steering. I am not really familiar with it on these cars so I will have to do some research on it. I wouldn't have thought they shared the same indicator bulb either. Maybe I will just leave the bulb alone then if I drop in the KYBs in and all. So in your opinion guys, anything else you guys would recommend that I do for an SC at this point? Again, I just bought it so am trying to cover the basics when you buy a used car without knowing its full past. It's a 90 with 61k. So far I have done the following: New battery and terminals, K&N, bought new SC plug and new fluid, Changed fuel filter, motorcraft plat plugs and wires, waiting for IC tube tape (had a low idle issue but found leak at the top) but if I don't like the tape I will just go with gaskets. Any other SC Tbird things that I am not familiar with that I should run through?

- cooling system (long list on it's own) - start with corroded terminal on temp sender
- belts and idlers
- motor mounts (oil filter hitting crossmember yet?)
- IAC
- multi-wire ignition switch down on side of steering column
- door hinges
- door and trunk seals
- moonroof seal
- headlights flickering?
- ARC brake pressure switch leaking?
- headlights dingy?
- driver's seat tracks stuck from old grease?
- speedo issues due to small plastic gear in head?
- power steering leaks (start with pump front seal)
- A/C system issues
- .....

And if the KYB change is too much, you might just want to find fresh ARC shocks and call it good.

KMT said:

- cooling system (long list on it's own) - start with corroded terminal on temp sender
- belts and idlers
- motor mounts (oil filter hitting crossmember yet?)
- IAC
- multi-wire ignition switch down on side of steering column
- door hinges
- door and trunk seals
- moonroof seal
- headlights flickering?
- ARC brake pressure switch leaking?
- headlights dingy?
- driver's seat tracks stuck from old grease?
- speedo issues due to small plastic gear in head?
- power steering leaks (start with pump front seal)
- A/C system issues
- .....

And if the KYB change is too much, you might just want to find fresh ARC shocks and call it good.

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I forgot to mention, I did an IAC, and also new MAF as I tried to fix a low idle issue. It seems to have been the seal at the top of the IC tube. I did all the belts, (idlers seem ok for now anyway) didn't see any issues with hoses. Lights seem ok as do the doors and seat, speedo, no moon roof, door and trunk seals, ignition all seem issue free, thank fully lol. Headlights are very good actually. I been so focused on figuring the idle issue that honestly I drove ti home (70 miles), drove to the shop about 9 miles and that's it. By Monday I should have it wrapped up and will see how this improved everything. We are going to put it back up on lift and go through any leaks or moisture.
I did notice some what I thought was power steering fluid drips but have to investigate further. It might be the front seal that you mentioned possibly. Thankfully over all the car handled great on the way home, had it up over 65 most of the way, hit 100 few times when I opened it up, no rattles, shakes or issues I noticed other than the stalls at lights, signs, traffic etc so hopefully I can clean up the little fixes one by one and see what's what. What were you referring too about the motor mounts and oil hitting the cross member? But I am glad to see your checklist and so far I got checks next to most of them !!

The driver's side motor mount usually lets go first - sometimes you can tell just be looking at the intercooler top tank to see if it sits at an angle compared to the header. When it fails bad, it drops that side of the engine so the oil filter-to-crossmember gap closes and risks contact as the engine torques up/down on that side. If you have trouble removing the oil filter, that may be why.

KMT said:

The driver's side motor mount usually lets go first - sometimes you can tell just be looking at the intercooler top tank to see if it sits at an angle compared to the header. When it fails bad, it drops that side of the engine so the oil filter-to-crossmember gap closes and risks contact as the engine torques up/down on that side. If you have trouble removing the oil filter, that may be why.

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Just curious about the top tank(3.8 marked tank). It should always sit level? I did notice when looking at it that the right back corner of it is actually higher up the the front left. Is this what you were referring too?