When we talk about battery problems, we almost automatically conjure up images of slow-cranking engines or the disheartening view of all the indicator lights going from dim to dark the instant you try to start the car. Granted, batteries can be stealthy saboteurs, operating perfectly until they hit us with the silent treatment. Determined not to communicate with the starter anymore and equally resolved to pay no attention to the alternator, they make a show of force (usually at the most inconvenient time) that they are totally independent of the rest of the vehicle. This obvious defection from the team immediately warrants a replacement with another battery that's all too happy for the opportunity. Sometimes, though, we aren't lucky enough to have a blatant battery insurrection.
While at the Corvette Clinic, a '98 came in with what seemed to be an HVAC problem. There was no control of defrost, heat, or vent positions inside the car. The Clinic did some diagnostic sleuthing and found that the system did not have a supply of vacuum to operate the valves. What do the vacuum system and electrical system have in common on a C5? Follow along and we'll show you.
1. This was our first clue...
1. This was our first clue that bad things were on the horizon.The battery side terminals were leaking acid. You can see how thebattery acid was running down the frame of the car, all too ready toclaim its next victim. Our first step was to wash the area thoroughlywith baking soda and water to neutralize the acid.
2. The main wiring harness...
2. The main wiring harness is directly under the battery, as isthe PCM. The acid was eating through the harness and, since the vacuumlines run as part of the harness, they were affected as well.
3. This is what is left of...
3. This is what is left of our C5's vacuum line for the HVACsystem. A 2-foot section of the line was affected. If this line hadn'tbeen affected, the acid would have kept eating away at the wires orfollowed the wires down to the PCM. That could have been reallyexpensive.
4. We continued to cut open...
4. We continued to cut open the harness to be sure the wiresweren't affected. The black specks around the wires are all that's leftof our vacuum line.
5. (above & right) The vacuum...
5. (above & right) The vacuum line for the HVAC goes under thebattery area next to the firewall to a vacuum canister. We disconnectedthe line from the canister to check for any other issues.
6. We used a stretch of 1/8-inch...
6. We used a stretch of 1/8-inch hose to replace the originalline. Don't use 5/32-inch because you can have a leak or the hose couldpull out. Also, never use silicone to help slide the hoses together. Itcould wind up in the oxygen sensor.
7. After cleaning all the...
7. After cleaning all the wires and checking for proper operationof the HVAC system, we rewrapped the harness with tape.
8. Before we installed the...
8. Before we installed the new battery, we laid down this BatteryMat. It's available online at www.dccarcare.com/battery.html. It'schemically engineered to absorb any stray acid that might exit thebattery. Even if you don't have a problem with your C5's battery now,for the price of this item, it's well worth having one around!