Editing How to find an electrical drain (section)
Jump to:
navigation
,
search
===Preliminary inspection=== #Test your battery and verify that it is capable of holding a charge. Charge if needed. #Using the test light, check all fuses and replace any that are blown. #Do a visual inspection of common problems (missing or loose ground wires, aftermarket radio or lights on a circuit always powered ON and not a switched circuit). ##On older vehicles you can get in the vehicle with all doors closed and not worry about a time out interval. Perform an under dash visual inspection. ##On most late model vehicles equipped with a Vehicle Control Module (VCM) and/or Body Control Module (BCM) there may be a time out interval (a certain length of time has to pass in order for the VCM and/or BCM to enter sleep mode where the computers will use less power. These are vehicle-specific and you will need to consult a proper service manual). #It is suggested that you consult the owners manual in order to familiarize yourself with the location of all fuse boxes. You will also need to verify that you have a legend for the fuses telling you what amp fuse to use in each circuit and what components the fuse feeds power to. At this time you will also need to determine which fuse feeds power to the interior lights; often it is labeled "courtesy". #Testing ##Ignition key off and all doors closed, and, all aftermarket accessories turned off. If the vehicle is equipped with an under hood light you will need to disconnect the wires going to it or remove the bulb. ##Disconnect the negative battery cable. ##'''Connecting DVOM''' ###Make sure the DVOM cables stay connected to their correct locations (and not touching any other part of the vehicle) throughout the entire testing procedure, except when instructed otherwise. If they become disconnected you will need to perform steps 3.2 through 3.4 again. Unless you have alligator clips or can secure your test probes you may need another person to help you perform these tests. ###Connect the DVOM black cable (connected to the '''com''' port of the DVOM) to the battery negative post ###Connect the DVOM red cable (connected to the port labeled '''A''' or '''Amps''') to the negative cable ###Touch the negative cable end to the negative post of the battery for at least 15 seconds, then break the connection and let the meter reading become stable- record the reading. ####Was the reading 0.050 A or less? #####'''Yes'''- You are ''not'' experiencing an excessive power draw . #####'''No'''- It was higher- you have confirmed there is a power draw. Continue with the next step. ##Disconnect either one of the DVOM cables. It is now safe for you to open the doors in order to gain access to the fuses. You will now need to remove the "courtesy" fuse, and perform step 3.4 again. ###Did the reading remain the same or very close? ####'''Yes'''- it remained the same (it is still too high) - there is NOT a problem in this courtesy light circuit. Continue testing. ####'''No'''- the amperage reading is LESS than before - there WAS an excessive power draw in this circuit. This is the problem circuit. #If readings are still in the unacceptable range after checking this circuit you will now begin the fuse panel isolation portion of this procedure. ##Begin by pulling the fuses one at a time while monitoring DVOM readings after each fuse is removed. When the amperage reading drops to an acceptable range, note the circuit it dropped on, set this fuse aside, and reinstall the fuses you already removed. Once all other fuses are installed verify the amperage is still below specification. If so, now you will reinstall the fuse in the suspect circuit and continue to the accessory/device isolation portion of this test. The amperage will increase (there IS an amperage draw) when you reinstall this last fuse.
|
Editing help
(opens in new window)
Personal tools
Log in / create account
Namespaces
Page
Discussion
Variants
Views
Read
Edit
View history
Actions
Search
Navigation
Main Page
Recent changes
Random page
Help
All articles
Start a new article
Hotrodders forum
Categories
Best articles
Body and exterior
Brakes
Cooling
Electrical
Engine
Fasteners
Frame
Garage and shop
General hotrodding
Identification and decoding
Interior
Rearend
Safety
Steering
Suspension
Tires
Tools
Transmission
Troubleshooting
Wheels
Toolbox
What links here
Related changes
Special pages
Terms of Use
Copyright
Privacy Policy
Your Privacy Choices
Manage Consent