I have a 1988 GTA 5.7L TPI Automatic. I am going to purchase a new computer for it because i believe there is a bad ground in it for one of the cooling fans. The secondary fan always comes on with the ignition. I have already checked the fan motor, the relay, the A/C low pressure switch and the wiring. Everything is OK. I replaced the low pressure switch and the relay with new ones, the problem is still there. The only thing left is the computer. I have talked to other people about this. I came across a Corvette owner that had the same problem and he said that he replaced the computer (nothing else) and the problem ceased. He bought the computer from Auto Zone for about $80. I was thinking of purchasing the same one from that store but for my particular vehicle. I just wanted to check and see if there were any better types of computers to look for. Are there any particular differences in which type of computer to choose from or are they all basically the same?

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1988 GTA 5.7L Auto
355 ci. block, SLP Cold Air Intake w/ K&N, fully modified MAF Sensor, TPIS 52mm Throttle Body w/Air Foil, Throttle Body Bypass Hose, Fully Ported and Polished Plenum, Nikel-plated Ported SLP Siamesed Runners, Ported TPIS Big Mouth Intake Manifold, stock heads w/ 1.52 Comp Cams Self-aligning Roller Rockers, TPIS ZZ-9 Roller Camshaft, TPIS Valve Springs, Cloyes True Double Roller Timing Chain, TPIS Adjustable Fuel Pressure Regulator, Balanced Bosch 22 lb/hr Fuel Injectors, MSD 6AL, Taylor 10mm Wires, Bosch Platinum +4 Spark Plugs, MSD Blaster Coil, March Underdrive Pulleys, 6 3/4" Vibratech Streetdamper, TPIS Level 3 PROM, 160 T-stat, Low Temp. Fan Switch, Stock Distributor w/ Bronze Gear, SLP 1 3/4" Headers, Random Technologies High Flow Cat., Adjustable Borla Cat Back Exhaust, Level 10 PTS-3 700R4 Trans, B&M Holeshot 2400 Stall Converter, B&M Trans Cooler, TCI Aluminum Finned Trans Pan, Torque Converter Lock Up Switch, 3" Balanced Aluminum Driveshaft, 3.73 Richmond Gears, Auburn Pro-Series Differential, LPE Aluminum Differential Cover w/ Main Cap Preloads, BF Goodrich Drag Radials, Hotchkis Lower Control Arms, Hotchkis Panhard Rod, Hotchkis Tie Rod Adjuster Sleeves, Bilstein Heavy Duty Shocks and Struts, 1LE Springs, Energy Suspension Polyeurethane Bushings, Global West Tubular Subframe Connectors, Global West Steering Box Brace, HP Motorsports 3 Point Strut Tower Brace

"Why ride a stang when birds can fly?"

http://www.geocities.com/thegta

 

I just installed the new computer from Auto Zone and found out that it is not the problem. What else can i check for? It's not the motor, not the low pressure switch, and not the ECC. I'm completely lost on this one.

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1988 GTA 5.7L Auto
355 ci. block, SLP Cold Air Intake w/ K&N, fully modified MAF Sensor, TPIS 52mm Throttle Body w/Air Foil, Throttle Body Bypass Hose, Fully Ported and Polished Plenum, Nikel-plated Ported SLP Siamesed Runners, Ported TPIS Big Mouth Intake Manifold, stock heads w/ 1.52 Comp Cams Self-aligning Roller Rockers, TPIS ZZ-9 Roller Camshaft, TPIS Valve Springs, Cloyes True Double Roller Timing Chain, TPIS Adjustable Fuel Pressure Regulator, Balanced Bosch 22 lb/hr Fuel Injectors, MSD 6AL, Taylor 10mm Wires, Bosch Platinum +4 Spark Plugs, MSD Blaster Coil, March Underdrive Pulleys, 6 3/4" Vibratech Streetdamper, TPIS Level 3 PROM, 160 T-stat, Low Temp. Fan Switch, Stock Distributor w/ Bronze Gear, SLP 1 3/4" Headers, Random Technologies High Flow Cat., Adjustable Borla Cat Back Exhaust, Level 10 PTS-3 700R4 Trans, B&M Holeshot 2400 Stall Converter, B&M Trans Cooler, TCI Aluminum Finned Trans Pan, Torque Converter Lock Up Switch, 3" Balanced Aluminum Driveshaft, 3.73 Richmond Gears, Auburn Pro-Series Differential, LPE Aluminum Differential Cover w/ Main Cap Preloads, BF Goodrich Drag Radials, Hotchkis Lower Control Arms, Hotchkis Panhard Rod, Hotchkis Tie Rod Adjuster Sleeves, Bilstein Heavy Duty Shocks and Struts, 1LE Springs, Energy Suspension Polyeurethane Bushings, Global West Tubular Subframe Connectors, Global West Steering Box Brace, HP Motorsports 3 Point Strut Tower Brace

"Why ride a stang when birds can fly?"

http://www.geocities.com/thegta

 

The ECM does not control the secondary fan relay. The secondary fan relay is controlled by a temperature sensor in the passenger side cylinder head, and, in some models there is also a liquid line high pressure switch that also controls the secondary cooling fan - it closes above a certain pressure. If I remember correctly, one of the wires going to the switch on the A/C system liquid line would have a gray wire going to it if controlled the fan & another color if the switch connected to the ECM.

Tim