Mapping Current flow through the JBs

Your use of the Power Source Matrix and System Circuit Diagrams is the same as when diagnosing a parasitic load problem.

Fig. 5-12

Circuit Junction Block Connectors

Junction C ID #

lonnectors Pin

Moon Roof

7(2D O O

Clock

7(H) (3)

Auto Antenna

7 (ST) 1 (ID Í2(1T) C }

J3

A

7 Qbj I GO föuO C j

J3

A

Combination Meter

^^Hmmmmmf^^^ ^^^mmmmtmuf^^

16(5A) O O O

2. Disconnect each junction block connector individually until the load turns OFF. By doing this, you are identifying which J/B connector provides power to the problem circuit. Reconnect the connectors.

3. In some circuits, a single J/B connector can distribute power from a fuse into a number of different circuits. You can isolate which terminal/wire is connected to the short-to-ground by using an inductive ammeter or by individually removing each terminal until the load turns off.

4. Look at the list of J/B connectors and terminal numbers that you wrote down earlier. See which circuits use that specific J/B connector and pin.

5. Look at the System Circuit Diagrams of the circuits from your list in step 1. Isolate circuits by disconnecting appropriate harness-to-harness connectors, watching for the load to turn OFF. This will further pinpoint the problem circuit, but you may still need to isolate which terminal/wire is connected to the short-to-ground by using an inductive ammeter or by individually removing each terminal until the load turns off. Also, you may need to cross-reference the various splice points between the circuits by looking at the individual wiring diagrams.

10. Continue to strategically disconnect/reconnect connectors in the circuits until you isolate the problem.

11. Once the location of the short-to-ground has been isolated, make the repair.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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