1990 FX3 suspension
Race Director
Joined: Feb 2002
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From: Compound in the Grove, Ga.
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St. Jude Donor '16
Just remove them and unplug and remove the actuators than the bulb from the DIC. You can also replace the switch assembly on the console with a non FX3 one.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Replacing the shocks is not terribly hard to do. The front shocks can be swapped even with the car on the ground!. The rear shocks are a little different. You have to remove the rear wheels and unbolt a small plate at the underside of the frame rail. Remove the nut at the bottom of the mounting stud, then pull the shock out. Remove the mounting plate and transfer it to the new shock and install the new shock.
The FX3 actuator is held in place on top of each shock by a circular spring clip. I would remove all of the actuators and keep them along with the clips. Disconnect the wiring at the connector and secure the harness so it won't get in the way. The rear wiring harness runs up inside the frame rail so secure them so that the don't fall down into the lower part of the frame. If you ever decide to return to the FX3 system, it will be a PITA to chase it.
The FX3 controller is located in the storage compartment behind the driver's seat. Remove the screw to raise the compartment lid. You should see the wiring harness that connects to the controller. Disconnect that harness from the controller. This should shut off the warning light (Service SRC).
The FX3 actuator is held in place on top of each shock by a circular spring clip. I would remove all of the actuators and keep them along with the clips. Disconnect the wiring at the connector and secure the harness so it won't get in the way. The rear wiring harness runs up inside the frame rail so secure them so that the don't fall down into the lower part of the frame. If you ever decide to return to the FX3 system, it will be a PITA to chase it.
The FX3 controller is located in the storage compartment behind the driver's seat. Remove the screw to raise the compartment lid. You should see the wiring harness that connects to the controller. Disconnect that harness from the controller. This should shut off the warning light (Service SRC).
Melting Slicks
Joined: Jan 2017
Posts: 2,099
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From: Minneapolis MN
Thread Starter
Instructor
Joined: Aug 2002
Posts: 198
Likes: 0
From: Yucaipa CA
Fx3
My non-FX3 1990, that I owned for 18 tears, suffered an electrical fire that damaged it beyond it beyond reasonable repair. I am looking to buy the 1990 with the FX3 suspension and replacing any questionable parts with the many newer parts that I can salvage from my car including the shocks. I have not yet looked at the candidate 1990 but am looking ahead to any potential problems. From my long experience with my damaged Corvette, any complex items, like the FX3, have either failed or have been disabled. If the FX3 works all is well.
Replacing the shocks is not terribly hard to do. The front shocks can be swapped even with the car on the ground!. The rear shocks are a little different. You have to remove the rear wheels and unbolt a small plate at the underside of the frame rail. Remove the nut at the bottom of the mounting stud, then pull the shock out. Remove the mounting plate and transfer it to the new shock and install the new shock.
The FX3 actuator is held in place on top of each shock by a circular spring clip. I would remove all of the actuators and keep them along with the clips. Disconnect the wiring at the connector and secure the harness so it won't get in the way. The rear wiring harness runs up inside the frame rail so secure them so that the don't fall down into the lower part of the frame. If you ever decide to return to the FX3 system, it will be a PITA to chase it.
The FX3 controller is located in the storage compartment behind the driver's seat. Remove the screw to raise the compartment lid. You should see the wiring harness that connects to the controller. Disconnect that harness from the controller. This should shut off the warning light (Service SRC).
The FX3 actuator is held in place on top of each shock by a circular spring clip. I would remove all of the actuators and keep them along with the clips. Disconnect the wiring at the connector and secure the harness so it won't get in the way. The rear wiring harness runs up inside the frame rail so secure them so that the don't fall down into the lower part of the frame. If you ever decide to return to the FX3 system, it will be a PITA to chase it.
The FX3 controller is located in the storage compartment behind the driver's seat. Remove the screw to raise the compartment lid. You should see the wiring harness that connects to the controller. Disconnect that harness from the controller. This should shut off the warning light (Service SRC).
Race Director
Joined: Feb 2002
Posts: 11,614
Likes: 1,055
From: Compound in the Grove, Ga.
2026 Corvette of the Year Finalist - Unmodified
2025 C4 of the Year Winner - Unmodified
2024 C4 of the Year Finalist - Unmodified
2020 C3 of the Year Finalist - Unmodified
2019 C4 of Year Finalist (performance mods)
2018 C4 of Year Finalist
2015 C4 of the Year Finalist
St. Jude Donor '16
Good luck in your hunt. Lots of very nice C4s on the market right now.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
IIRC, when the FX3 sets a code, (like removing the shocks) it limits the car's top speed to something like 85 MPH. Casper's has a kit that plugs into the harness and remedies this problem. I would think removing the connectors from the FX3 module would also disable the speed-limiter too. Does it?
I have read lots of posts here where owners have removed the FX3 shocks and actuators and never mentioned finding a speed limitation. My old '92 had FX3 and never had a speed limiting problem when I had to wait for a week to get a replacement actuator. A code was set because of that and I cleared it after installing the new part. I don't recall seeing anything in the Selective Ride Control section of the FSM that talks about limiting speed because the system is not working properly.
Team Owner
Joined: Jul 2004
Posts: 28,459
Likes: 3,288
From: Hartford WI
I would be more than that less. I would figure that for a restoration, assuming the harness is good, you have no actuators that are in working order and no shocks and module is suspect. Not that if I were to buy a C4 today I would make it work but that would be what I value it as.
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