2000 Chevrolet Blazer Repair Question
Why when the key is off is my RAP fuse under the hood drawing power causing a new battery to drain overnight?
sounds like a wiring issue. trace the radio wire back to the plug.
by the way, RAP???? please explain
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Retained Accessory Power (RAP)
3 questions asked
Hi guys. Allow me to add some insight that is likely involved. You can't use a test light as you described to test for a drain. Unless specified otherwise, only 35 milliamps, (.035 amps) is allowed for the radio and computer memories. That's WAY too small to light up a test light so you can have an excessive drain without the light being on. The test light routine worked many years ago when the only drains were stuck trunk and glove box lights that drew a half amp or more.
Second, you have computers that have to time out and go to "sleep mode". Until that happens, often up to 20 minutes or more, those computers can draw as much as three amps in total. Your test light won't allow that much current to flow so the computers will try to shut down, wake up, shut down, hence the flashing light.
You have to do this with a digital volt - ohm - amp meter but there is still a problem. If you use the 200 ma range for accuracy you are likely to blow its internal fuse. You can start out on the two amp scale, then after 20 minutes switch it to the lower scale but just turning the switch will momentarily brake the circuit and wake the computers up again. That will also blow the meter's fuse. Hmm!
Check out this page for the solution. Go half way down to "Computer-Controlled Cars".
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