So who uses a test light to check for blown fuses?

[The Green GT]

I used to but the reason my gauges werent working was the fuse, and I checked it 4 seperate times with a test light and it worked. I put the light on both sides of the fuse and it lit up. I dont understand how that happened but Im happy its fixed. But when I REMOVED the fuse and saw it was blown, I put it back in and used the test light. IT WORKED. I was

 

[94gts]

if you put the light on the contacts it will light up unless there is a problem in the wiring. yea fuses are pretty much visual. dont worry. ive had pleny of this before

 

[moneypit94]

We had some fuses give us a hell of a time at the car/home audio place i work at part time.

The thing is they looked good and tested ok for continuity. But we had 3 cars come back in with what they thought were blown amps. The amps tested ok but still would not work in that particular vehicle.

After we played around with a bunch of stuff we put a different brand of fuse in and it worked fine. Later after playing with the fuse we found that it was just good enough to test ok for continuity but that was it. We do not carry that brand of fuse anymore. (these were the glass tube type fuses)

 

[SeventyMach1]

Haha .... if you wanna really screw with someone (this can be mean, lol) ... take out one of their fuses, like for the radio or something. Neatly put some CLEAR TAPE over the contacts. Make sure the fuse looks NORMAL, with no tape being visible. Re-install fuse. The radio (or whatever you chose to pull) will not work. It will take them forever to find out what happened (or they may never find out!).

I know I'm putting you guys up to no good, lol. Be sure to tell them what you did after they've tried to fix it for a while. If you want.

 

[The Green GT]

Haha .... if you wanna really screw with someone (this can be mean, lol) ... take out one of their fuses, like for the radio or something. Neatly put some CLEAR TAPE over the contacts. Make sure the fuse looks NORMAL, with no tape being visible. Re-install fuse. The radio (or whatever you chose to pull) will not work. It will take them forever to find out what happened (or they may never find out!).

I know I'm putting you guys up to no good, lol. Be sure to tell them what you did after they've tried to fix it for a while. If you want.

Man that would suck if the tape came off in the connections.

 

[HISSIN50]

Note to self: Remove visiting Justin from my cross-country road-trip to meet fellow SN'ers. J/K.

Here is the thing - a fuse can blow to not carry hardly any amperage, but it will have a hair of metal still closing the circuit to reflect continuity (meter will show voltage).
Said another way, we can remove a battery cable and put a paperclip in-series between the removed lead and the battery. A test light or DMM will show 12 volts flowing through the paperclip, but this in no way reflects the amperage the circuit can handle.

 

[mo_dingo]

Note to self: Remove visiting Justin from my cross-country road-trip to meet fellow SN'ers. J/K.

Here is the thing - a fuse can blow to not carry hardly any amperage, but it will have a hair of metal still closing the circuit to reflect continuity (meter will show voltage).
Said another way, we can remove a battery cable and put a paperclip in-series between the removed lead and the battery. A test light or DMM will show 12 volts flowing through the paperclip, but this in no way reflects the amperage the circuit can handle.

Yup, that is the truth right there. I have seen a fuse test good but not pass current through because the tab is actually broken, so the top has current on both sides, but it won't pass it through to the fuse block.

If you are not getting 12V+ to something testing the fuse isn't where you stop. You have to test the block; thus it is necessary to identify the load wire and make sure it's getting power, comfirming the block is passing power as well.

A test light is still the best way to test a fuse that I know, regardless of it's extremely sporadic failures.
Scott

 

[The Green GT]

A test light is still the best way to test a fuse that I know, regardless of it's extremely sporadic failures.
Scott

But man that was aggrivating driving with NO gauges for a week and a half.