How much voltage?

[18lexusowner 10+ year member]

Could the DMM or AMM not be able to pick up the very little voltage going through the RCA's?

Even at 15v setting.

 

[microhaxo 10+ year member]

Put your neg on the ground of the AMP or battery or something grounded, you want the DMM set on AC V, with the red touch and you shal see powa! not much more than say 0.4v ..

 

[MakeshiftAudio 10+ year member]

Post 400.

Well, the output module could be shorted is what I'm going after. I have had it happen in some headunits.

How do people not know how to use a DMM?

Put the setting on ohm, on the lowest setting, and put one probe on the inside of the RCA, the other on the outside terminal of the RCA. Is it getting 0 or near 0 resistance? Only do this test while the HU is off. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Either way, it seems your RCA outs are dead.

 

[18lexusowner 10+ year member]

Oh test it just with the terminal!

I was testing it by going from the RCA ground to metal on the car. Was getting about .1 ohm i believe.

Put your neg on the ground of the AMP or battery or something grounded, you want the DMM set on AC V, with the red touch and you shal see powa! not much more than say 0.4v ..

Gonna try this and then also the other thing makeshift said. Will post results in a few mins.

 

[18lexusowner 10+ year member]

Did some more tests.

Tested preout ground to preout ground=no reading

Tested inside preout to preout shroud=no reading

Tested amp side RCA shroud to amp grnd with HU on=No reading in ACv

Tested amp side red RCA shroud to white RCA shroud=1.8 ohm DMM has .8 ohm so it's 1 ohm.

Tested amp RCA pin to pin=39.5 ohm-.8 ohm 38.7 ohm.

That's just the tests I thought of and also trying what you guys suggested. No real readings that mean much I think. Still goin with a bad head unit. I'm going to the local audio shop tomorrow to see what he thinks.

Any thoughts? This is really aggravating. HU worked perfect a week ago before I sold my other subs.

 

[psych0ticnemes1 5,000+ posts]

Test the ground of your head unit and amp. If anything but 0 is returned, your ground isn't good enough. Some amps are fickle. One amp could work fine with an ok ground, others require a perfect ground.