4) Disconnect the test light from the positive post on the battery. Make sure the positive battery cable does not touch the positive post. Either unplug or remove the battery circuit from the ignition switch. Be sure to insulate the end of the wire, as it is a battery hot-circuit, and you do not want it to short to ground. Reconnect the test light to the positive post on the battery. Take note of the brightness. If you see a dramatic change, a circuit from the ignition switch is causing a drain and more extensive diagnosis is required. If there is little or no change, go to step five.
5) At this point we have checked every hot-circuit with the key off. One or more of these circuits should have made a difference. If none of these circuits had any effect on the brightness of the test light, have the state of the battery checked. Be sure the battery is fully charged before checking its state.
Oil Cooler Cure
Scott Meyer, Bensalem, PA: I have a '95 Trans Am with the original LT1 engine and a six-speed trans. The car has what appears to be a factory oil cooler that uses an adapter between the oil filter and the block to source oil for the cooler feed and return lines. The problem is that I have a persistent oil leak at this junction, and even though I've tried to tighten the two Allen-head bolts that hold the adapter to the block, oil keeps leaking. I pulled it off and changed the O-ring, but it still leaks. What's the deal?
Terry McGean: Engine oil coolers became fairly common on GM trucks and performance cars in the late '80s, and most use similar adapters and lines. The main difference seems to be with the type of cooler-some use an oil-to-water cooler integrated with the radiator tank (like a trans cooler), and some use an external oil-to-air cooler mounted ahead of the radiator. The engine adapter is the same in most cases regardless of cooler type. It's also common for these setups to leak, often from the fluid-line assemblies, which use rubber flex hoses coupled to aluminum hard lines with crimped junctions. The fluid-line leaks are usually at the crimped junctions, though sometimes the hoses themselves split. Either way, repairing them means replacement. But the leak you describe does indeed sound like it's coming from between the block and the adapter. The O-ring you changed is only part of the sealing for that arrangement-there should also be a gasket between the block and the adapter, though from what we've read, some vehicles seem to have been assembled without the gasket. Even those that have it can tend to leak, and usually, once the leaking begins, tightening the Allen-head-adapter mounting bolts won't cure the problem. The gasket and O-ring seem to have been updated by GM, which now offers them together in a seal kit (PN 88893990). The new O-ring is black, replacing the orange factory piece, and the new gasket has a metal reinforcement plate sandwiched between the gasket material. The seal kit should cost less than five bucks at the dealer. We recently went though this process on our '96 police-spec Caprice and were warned by a dealer tech that getting the old gasket off would be a chore ... he was right. We used some aerosol gasket remover to soften it up and continued to scrape it with a hand-held razor blade. The Allen bolts should be torqued to 17 lb-ft when reinstalled. Ours seems to have stopped leaking as a result.