Test for ALWAYS ON fuse with this multi-meter...PIC!

[tsouzee]

Hello. I'm looking to find an always ON fuse in my 2017 Subaru WRX, so I can hardwire a dashcam into (QVIA T790). I need it to be on even when the the car is off. I purchased this multimeter but have no clue how to use it. I'm not looking for a tutorial on using multi-meters. Just want to know where I need to switch it to and where the leads need to go and what type of reading I'm looking for in this particular situation only. I looked online but the only tutorials I found show how to test an actual fuse after pulling it out. I appreciate any help.

 

[Paul Schmehl]

Touch the ground probe to a screw on metal under the dash. Then use the positive probe to touch the fuses until you get 12v with the ignition off and accessory off. Try not to use a fuse for a major system like the air bags or computers on the car.

 

[flip9]

Set to DC volts 20 range. Its the V with broken lines underneath it.

Attach BLACK probe to a bare metal part of the body. There should be grounding points on the kick panel just remove the trim.

Start probing with the RED probe. When you get a reading of 12v~ then you have an active circuit.

You dont need to pull out the fuses btw, theres probing points on the top of blade fuses.

 

[jokiin]

turn the dial 3 clicks to the left to 20

black cable in the bottom right plug, red in the one above it

check voltage of your car battery to make sure it's working before you go any further

 

[Sunny]

Always on fuses are usually for critical features like computer, alarm, steering wheel lock, disabling the car etc... So I suggest looking for something that is not critical as the fuse box should have everything listed on what does what or using blank fuse holders if you have any.

Just to detect voltage, any DC voltage mode works except the high ones. Even high ones work in good meter that displays to few decimal points but not sure on yours.
MV modes like 200m, 2000m will give you more 0 in the back but is enough to see whether voltage is there or not.
Don't use the top hole, that should be for A/C.

 

[Ralph2]

Use the label on the fuse cover that describes what each fuse does. Pick one that is always on like your brake circuit. A good one to pick for on with key is the radio circuit. You can prove that the fuse you pick is the right one by pulling it out and checking the application.. ie pull the brake fuse and see if the brake lights still work. Same test for the "on with the key".
Do NOT pull fuses while the car is running or key is in the ON or ACC position.

 

[dash riposki]

Too late now, but for doing what you want to do, these are cheaper, and easier.

(I'm annoyed most of the cheap multi-meters you can find rarely have audible continuity)

 

[Sunny]

Too late now, but for doing what you want to do, these are cheaper, and easier.

(I'm annoyed most of the cheap multi-meters you can find rarely have audible continuity)

I think the multimeter is cheaper.
I have few of them either free when buying something else or $4 in harborfrieghts.
They do have continuity test (I think one step to the right from bottom center on mine) but why use that when voltage is there? Continuity is better for testing wire ends to figure out what end belongs to what tip without power.

 

[Ralph2]

Too late now, but for doing what you want to do, these are cheaper, and easier.

(I'm annoyed most of the cheap multi-meters you can find rarely have audible continuity)

There is a small risk in using that to test for power. With current electronics if you back feed the circuit you could do damage even possibly set off your airbags.

 

[tsouzee]

Thank you all for your replies. I will try this tonight. It seems the hardest part of the whole dashcam process is going about the install the right way (when hardwiring). I almost gave up a few times but it's worth it to have one. I am horrible when it comes to electronic wiring

 

[jokiin]

There is a small risk in using that to test for power. With current electronics if you back feed the circuit you could do damage even possibly set off your airbags.

old school test lights are too risky with a lot of cars, LED versions are safer but multi meter is still the way to go

 

[iptelman]

I've found this to be a great "cheap" meter: https://www.amazon.com/gp/B015OFMUYO

 

[Paul Schmehl]

I just bought a three pack Southwire DVOM plus plug tester plus voltage probe for $29.98 at Lowes. Strangely, it's not on their website.

 

[tsouzee]

Thanks everyone for your help. I tested some fuses and found a wiper deicer and D-OP + B (not sure what that does) fuse to be always on. My camera actually came in today and realized I may need to tap into TWO fuses (always on and ACC).....so I'll probably need to start a new thread. I guess I need to order another add a circuit as well?