Connect an Appropriate Load

The lamp will go OFF when the short has been disconnected.


Your next step in this process of elimination is to disconnect individual connectors. Where to start is not as "clear cut" as it is with a parasitic load. Here are the advantages and disadvantages of two strategies:

Disconnecting Component Connectors First

Using Section H, Power Source (Current Flow), determine which components are connected to that fuse. If the components connected to the blown fuse are accessible, and there are not too many, it can be a quick means of eliminating some of the possible causes. But if the problem is in the harness, you will have to use the "mapping current flow through the Junction Blocks" technique.

Mapping Current Flow Through the J/B's

This method is similar to the procedure used in the parasitic load diagnosis section, except that you are watching for the load to turn OFF, instead of watching the ammeter. Because the current flow in the circuit will be a few amps instead of milliamps, you can use an inductive ammeter to isolate which individual wire at the J/B connector feeds to the short-to-ground. This is much easier than removing the individual terminals from the J/B connector.

1. Determine which Junction Block Connectors are fed by that fuse. Look at each System Circuit Diagram for that specific fuse at the top of the page. Note any Junction Blocks or Junction Connectors that are used, and write down the connector and terminal numbers. Again, this is a time consuming step, but it must be done.

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