Question:I hope you can help me with my '98 Corvette. The car is displaying random DTCs [diagnostic trouble codes], the headlights dim occasionally, the dash lights flicker, and other unusual problems occur when I hit bumps in the road. I've replaced the headlight switch and the alternator, and checked all the fuses.
Via the Internet
The majority of C5 electrical glitches can be traced to chassis grounding problems. These are usually caused by corrosion in a chassis ground plug (Image 1) due to moisture building up on the contacts.
While there are several ground connectors on your C5, the underhood contact located inside the driver-side fender (Image 2) is the most likely culprit. Completely disassemble the ground plug and clean the contacts with contact cleaner and a small wire brush or Scotch-Brite pad. Once the contacts are clean, spray them with white lithium grease and reassemble the connector. This can typically be done in 30 minutes.
Unfortunately, the corrosion will eventually return. The only permanent solution is to cut off the underhood chassis ground connector and solder all of the wires into a single ground lug.
While you have the hood up, check your battery terminals to verify that they're torqued to 11 ft-lb. You should also make sure that the positive battery post is not loose or leaking, as this can cause an array of electrical issues. Finally, double check the connection at the alternator to confirm that it's tight.
I have an '07 Corvette that's just started to make some popping noises in the roof. I've checked my weatherstripping and even taken the car to the dealer, but nothing has worked. Have you had any other complaints on this, and, if so, what is your advice?
Via the Internet
This is a common complaint, but fortunately there's a simple solution. Chevrolet has issued a technical service bulletin, No. 08-08-67-13A, to correct the problem. The popping noise you're hearing could be caused by the roof-panel latching handles. What happens is the nylon rollers inside these handles can come loose, allowing the rollers to move on the pins. This movement causes the popping sound. The fix for this is to replace the left and right front roof panel handles and lube them at the same time. The new handles are designed without the nylon rollers.
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