Looking for Recommendation for a Cheap Multimeter with Ammeter Function

[Used_Cars]

My truck has an electronic leak. I think it's either the alarm system (factory) or the stereo system (aftermarket and has TEENAGER screaming all over it). Battery doesn't have enough power to even turn the dashboard lights on after 3 days of sitting there.

Watched a Youtube video, and the guy said to check current flow from the ground side because it's safer than measuring at the 12 volt post. My multimeter is ancient and doesn't have ammeter function.

I just need it for this one test and OfferUp has used Flukes at $180.

Any recommends?

[Used_Cars]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

I went shopping and found this:

https://goo.gl/xfr7LM

What do people think? It's five bucks.

[stj]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

your in the u.s. - those are at Harbour freight and often given free when you buy stuff.
they cost a lot less than that from china btw - more like $3-4 inc shipping.

i shouldnt need to point out that they are shit

[Andrew F. Ali]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

If you have Sub-woofer Amps or even any Hi-power Amps connected as part of the Audio system, that could be draining your battery if the are connected directly to the battery. There is usually a connector with 3 screws to power these Amps. 1. +12V to Battery, 2. +12V to switch and 3. GND. They may be in any order not exactly as I have listed but the 2. +12V to switch could be keeping the Amp/s on all the time.

[desert-rat]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

In agrement with Stj harbor fright has some cheep volt ohm meters . They have one for $20-25 . My first thought would be how good is your battery . Next thought would be a light staying on , or a bad dioen in the alt.

[Used_Cars]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

If you have Sub-woofer Amps or even any Hi-power Amps connected as part of the Audio system, that could be draining your battery if the are connected directly to the battery. There is usually a connector with 3 screws to power these Amps. 1. +12V to Battery, 2. +12V to switch and 3. GND. They may be in any order not exactly as I have listed but the 2. +12V to switch could be keeping the Amp/s on all the time.

I did some reading last night after posting this and taking the "it's the aftermarket stereo system" theory one step further, one guy I read said that these aftermarket bass units (the truck has a huge one) get turned on by the head unit, and then wait for the head unit to tell them to turn off. If the head unit doesn't send some kind of "off" signal, the bass unit stays on constantly until the battery dies.

Well. In my case the battery never actually dies; it just depletes down to the point that things stop working. I can always get the truck started again with a jump, so it's not fully discharged all the way down to 0%.

So if this is the problem I don't know what the solution is, other than pulling the bass unit and tossing it in the trash. I hate bass in my music anyways. Hearing that "THOOM THOOM THOOM" at a stop light makes me want to shoot up a school full of teenagers in retaliation.

[stj]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

the amp usually has an led indicator on it

[will62]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

Go to your fuse box and measure voltage drop across each fuse. If your meter will not read millivolts, borrow one that will or order a $5 one off ebay like this one:

https://www.ebay.com/itm/Red-LED-5-D...8AAOxyQyJRlcPq

[Curious.George]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

My truck has an electronic leak. I think it's either the alarm system (factory) or the stereo system (aftermarket and has TEENAGER screaming all over it). Battery doesn't have enough power to even turn the dashboard lights on after 3 days of sitting there.

Are you sure there aren't any lights on that shouldn't be? (glovebox, ashtray, under hood, etc.)

Watched a Youtube video, and the guy said to check current flow from the ground side because it's safer than measuring at the 12 volt post. My multimeter is ancient and doesn't have ammeter function.

Measuring in the ground leg vs. power leg is immaterial. The current has to flow in a loop so any side of the battery is as good as any other.

The admonishment re: the 12V terminal is in case you "slip" and short the probe to some portion of chassis (which is ground). This would be bad IF you are measuring the current "in-line" (disconnect one lead from battery, insert meter between battery terminal and disconnected lead) AND your multimeter isn't fused (if its fused and you "make an oops", you blow the fuse in the multimeter).

If you use a clamp-on ammeter, then you're never really in electrical contact with any part of the circuit so any place is as good as any other!

I just need it for this one test and OfferUp has used Flukes at $180.

Any recommends?

For a one-time use, if in the US, go to your local Pep Boys, OReilly, etc. auto parts store and BORROW a meter. Won't cost you anything (other than your time to pick it up and, later, return it)

The trick is deciding how big of a load represents "too large". Skipping over that little detail, once you are set up to monitor the current with the car not running, ignition OFF, doors closed, (cuz the dome/courtesy light will draw a lot of power) etc., you can remove fuses one at a time and notice the changes in the current measured. (note reading, pull fuse, note new reading, reinsert fuse, lather, rinse, repeat)

Start with what you suspect most (aftermarket add-ons). The car (truck) manufacturer has obviously NOT designed the vehicle to run down its battery during normal use. So, some additional item is playing vampire. Or, some wiring error (pinched conductor?) is typically your problem.

Remember, removing power from some things can make them forget! So, think real hard before you pull a fuse: "Will this screw anything up that I will later regret?"

[Curious.George]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

So if this is the problem I don't know what the solution is, other than pulling the bass unit and tossing it in the trash. I hate bass in my music anyways. Hearing that "THOOM THOOM THOOM" at a stop light makes me want to shoot up a school full of teenagers in retaliation.

Disconnect power from bass unit. Let car sit for 4 days. See if you can start it.

[petehall347]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

these work well . http://autoelectricalpartsuk.co.uk/i..._category=true

[desert-rat]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

Its either something running the battery down while its turned off , the alt is not keeping it charged or the battery going down whle turned off . If you have around 14 volts while running the alt. is probly good . If you take one battery lead off ( while turned off ) and hook up a 12 v bulb . If the bulb lights up you have some thing going to ground .

p.s. A general purpose volt ohm meter , a number of other places have them as well
https://www.harborfreight.com/11-fun...ity-61593.html

[petehall347]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

check for reports of that vehicle doing same thing with others .. i had one car in and it turned out to be the body ecm waking up too much and using all battery power . i couldnt see any excess current draw at all . software update may have fixed it but i fitted the device i posted above . that stopped the battery going flat
.

[eccerr0r]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

Dang wish I could just give you these free with purchase coupon for the crappy HFT multimeter... I get them time to time.

Here's another trick you can do without an ammeter. Disconnect the battery terminal and hook up a light bulb... YES, DIM BULB tester... in series. Those slender 1cm x 3cm bulbs with the wire or cap contacts on both ends are around 12W I'd say is a good tester bulb.

Anyway you should suspect any audio device that can be turned on without the key in the ignition... I suspect teenagers won't like this as they claim their audio is more important than the car starting, but it's a good safety policy to put it controlled by the ignition key. With a typical car battery capacity around 50 ampere hours, 3 days means a good portion of 1 ampere is being drawn constantly. They say that this number should be less than 100mA.

With that above 12W bulb, focus on trying to get the lamp to at most be very dim. If it's lit bright in any way, you're drawing too much current when off! There, no ammeter needed!

[desert-rat]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

This meter is rated for d.c. amps , if I understand how its worded . You would hook up a d.c. amp meter to the cables out of the battery , see if any thing is still drawing power after ever thing is shut off . It would work for ever thing except the starter .
https://www.amazon.com/bayite-Digita...s=dc+amp+meter

[stj]

Re: Looking for Recommendation for a Cheap Multimeter with Ammeter Function

actually, this is the type of place you want a UNI-T UT-210e