Dear Forum;

How do I test all auto fuses using the digital multimeter 3300. I am testing the fuses in a lexus es300.

Thank you.

Mike2

 

1. remove fuse from automobile
2. set multimeter for ohms
3 place meter leads (one at each end of fuse)
4 if fuse is good, meter will read near zero
5 if fuse is bad, meter will read very high number or OL (depends upon the meter)
6 if fuse checks good, re-install in vehicle
7 if fuse checks bad, buy new one and install new one in vehicle.

 

You can frequently test them when they are still plugged into the fuse box.

Here's an example:

Do you see the horizontal metal lines that are about 1/2 way between the "10" and the ends? Those are electrically connected to the two tabs.

You can turn on electrical power to the accessory that is not working, and use a meter set to the 20v (or automatic voltage) range, and see if there is a voltage across the fuse. If it measures 0v, the fuse should be OK. If you measure voltage, the fuse is definitely burned open.