Testing auto fuses with a digital multimeter

Thread Starter

Mike2

Joined Dec 11, 2011
1
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
 

BillB3857

Joined Feb 28, 2009
2,540
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.
 

SgtWookie

Joined Jul 17, 2007
22,220
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.
 
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