Help! Shorted out crank fuse?

[Londoner]

Hi - This is completely new to me, so here goes. In the fall before storing my 1988 Corvette, I shorted a 15amp fuse that controls courtesy lights, underhood lights, power antenna, etc. (fuse is labelled ctsy/clk). I've replaced this fuse and problem solved. However, perhaps coincidentally when I start the car, the "Service Engine Soon" lights and stays on, the oil pressure gauge shows 400 plus (metric measurement in Canada), the fan under the hood runs continuously, and the car chokes out after a few minutes. The car will restart but all symptoms remain. I thought perhaps I also shorted the crank fuse, which controls oil pressure and the fuel pump, but I cannot locate this fuse which according to the manual is behind the Driver Information Center, and part of I/P harness. Has anyone ever found this fuse to check, or perhaps have other suggestions as to what the problem could be? I'm in the situation of having to flatbed the car if I can't resolve this myself. Thanks for bearing with my long winded post!

 

[toptechx6]

Hi - This is completely new to me, so here goes. In the fall before storing my 1988 Corvette, I shorted a 15amp fuse that controls courtesy lights, underhood lights, power antenna, etc. (fuse is labelled ctsy/clk). I've replaced this fuse and problem solved. However, perhaps coincidentally when I start the car, the "Service Engine Soon" lights and stays on, the oil pressure gauge shows 400 plus (metric measurement in Canada), the fan under the hood runs continuously, and the car chokes out after a few minutes. The car will restart but all symptoms remain. I thought perhaps I also shorted the crank fuse, which controls oil pressure and the fuel pump, but I cannot locate this fuse which according to the manual is behind the Driver Information Center, and part of I/P harness. Has anyone ever found this fuse to check, or perhaps have other suggestions as to what the problem could be? I'm in the situation of having to flatbed the car if I can't resolve this myself. Thanks for bearing with my long winded post!

If the Service Engine Soon light is illuminated you have a DTC or Diagnostic Trouble Code stored in the ECM. Many codes will also cause the fan to run continuously with the key on. See this link to retrieve any codes in memory then post them here for further assistance.

C4 Corvette Diagnostic Code Recovery Techniques

Proper diagnosis of the codes also requires a Factory Service Manual and usually a Digital Volt Ohm meter. A code that mentions the O2 sensor for example does not mean the sensor is bad, it simply means the ECM (Engine Control Module) has seen a voltage reading on the circuit that is outside normal parameters, the code could be caused by wiring or even other fuel, ignition or mechanical problems. The flow charts in the FSM systematically test the circuit to isolate the root cause.

 

[Londoner]

If the Service Engine Soon light is illuminated you have a DTC or Diagnostic Trouble Code stored in the ECM. Many codes will also cause the fan to run continuously with the key on. See this link to retrieve any codes in memory then post them here for further assistance.

C4 Corvette Diagnostic Code Recovery Techniques

Proper diagnosis of the codes also requires a Factory Service Manual and usually a Digital Volt Ohm meter. A code that mentions the O2 sensor for example does not mean the sensor is bad, it simply means the ECM (Engine Control Module) has seen a voltage reading on the circuit that is outside normal parameters, the code could be caused by wiring or even other fuel, ignition or mechanical problems. The flow charts in the FSM systematically test the circuit to isolate the root cause.

Thank you for the advice. I shorted the pins as suggested, however, could not detect any ECM codes. The fan does falter after a while, there is an electrical shorting sound in the engine compartment and the "Service Engine Soon" light flickers, the fan recovers and blows continuously. On one occasion, the car started and appeared to function normally. I restarted and again it appeared normal. I shut the engine off, left it to retest the ECM, the problem resurfaced. Now I'm more confused than ever.

 

[toptechx6]

Your reply is confusing me, are you sure the "flickering" SES light is not flashing codes?

 

[Londoner]

Help

Sorry to confuse you. The "Service Engine Soon" flickers only when the fan falters. Otherwise it is constant. When I short the Diagnostic module, it flashes only the code "12" as per instructions (i.e. flash, pause, flash, flash, long pause etc.) I should mention on one occasion last summer, I stopped to gas up, and when I went to restart, there was nothing when I turned the key. I had to let the ignition reset to start. Perhaps this is another unrelated problem, but I read that GM has issued a Bulletin that relates to this faulty component.

 

[toptechx6]

I think I would check the battery condition and state of charge and verify the cables are clean and tight, then try again, good luck.

 

[metoo1012]

Possibly a bad ground connection there are several of them from just behind the headlights to under the motor. Check the manual for their location. Take the ground wire off and clean them.

Earl

Side mount bat cable? If so they can lose contact internally

 

[Londoner]

Help

Thanks once again: I've checked the battery charge and connection, and all seems OK - my car is being taken to my mechanic on Monday (He has a beautiful torch red C5 convertible) and I'll post the results.

P.S. The weather is finally looking better here, and I want to drive my car, top down.

Post soon!