Negative Ohms Reading On Speakers?

[Innovative:Cory 10+ year member]

Touch them together until they read at or about 0ohms.


Obviously that is a given. He was asking why it was reading negative.

Thats funny, I was directing that statement to you .....You where to one who told him he had the leads backwards..... it doesnt matter when measuring resistance!! You can put the positive lead of the dmm on the negative lead and still have the correct reading.

 

[mokedaddy 5,000+ posts]

What amp and how are your speakers wired?

 

[mokedaddy 5,000+ posts]

Thats funny, I was directing that statement to you .....You where to one who told him he had the leads backwards..... it doesnt matter when measuring resistance!! You can put the positive lead of the dmm on the negative lead and still have the correct reading.

I understand that. But again he asked why it was reading negative ohms. That is the answer. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Innovative:Cory 10+ year member]

op, here is the easiest way to find out what is wrong....

disconnect rca's turn radio on.....does amp go into protect yes or no, if it doesn't then you have a problem in head unit or rca cable itself...

disconnect speaker leads, turn radio on....does amp go into protect yes or no, if it doesn't then you have a speaker problem....

disconnect both rca's and speaker leads, turn radio on, does amp go into protect? if it does measure voltage on power wire at the amp, and the remote turn on...

how many amps are you trying to turn on from your head unit, are you using a step up relay on the remote turn on?

If voltage is good on all wires then you have a bad amp!!

 

[walkychalky 10+ year member]

voltage at protected amp? RCAs shouldnt put an amp into protect, unless the volts are too high.
DMM the RCAs with the radio on and see what you get

check for volts right??....ill do that right now

 

[Innovative:Cory 10+ year member]

I understand that. But again he asked why it was reading negative ohms. That is the answer. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

YOU ARE WRONG!!

go grab a dmm and set to Ohm and measure a speaker with the leads backwards.....

then come and tell the class what you find...

Let me break this down for you.....

when you use a dmm and measure VOLTAGE...if you have the leads backwards you will display a Negative voltage reading...ie...(-12.6)

when you use a dmm to measure RESISTANCE ....it doesn not matter if you have the leads backwards or not...it will still read the same...i.e. (4) or (7.8) or whatever....

Understand?

 

[Brian Owens 10+ year member]

Check from each speaker wire to DC chassis ground. Maybe you have a speaker wire that is pinched and shorted to ground.

 

[mokedaddy 5,000+ posts]

YOU ARE WRONG!!
go grab a dmm and set to Ohm and measure a speaker with the leads backwards.....

then come and tell the class what you find...

Let me break this down for you.....

when you use a dmm and measure VOLTAGE...if you have the leads backwards you will display a Negative voltage reading...ie...(-12.6)

when you use a dmm to measure RESISTANCE ....it doesn not matter if you have the leads backwards or not...it will still read the same...i.e. (4) or (7.8) or whatever....

Understand?

Than explain to me why it was reading negative then?

 

[mokedaddy 5,000+ posts]

op, here is the easiest way to find out what is wrong....
disconnect rca's turn radio on.....does amp go into protect yes or no, if it doesn't then you have a problem in head unit or rca cable itself...

disconnect speaker leads, turn radio on....does amp go into protect yes or no, if it doesn't then you have a speaker problem....

disconnect both rca's and speaker leads, turn radio on, does amp go into protect? if it does measure voltage on power wire at the amp, and the remote turn on...

how many amps are you trying to turn on from your head unit, are you using a step up relay on the remote turn on?

If voltage is good on all wires then you have a bad amp!!

Could also be a speaker wired grounding out or trying to wire the amp too low.

 

[Innovative:Cory 10+ year member]

Than explain to me why it was reading negative then?

If you are paying attention, you will notice I asked if he was taking his readings with the radio on.....

He said he was.....

That was the reason his reading was wrong.

He was getting a measurement from the amp itself... More than likely since there is something wrong with the amp, me may have gotten a voltage measurement instead. That would just depend on the type of meter used. Some will automatically transfer from Impedence to Voltage with you having to make an adjustment.

 

[mokedaddy 5,000+ posts]

He also stated that he switched out amps and was still having the problem. Thus meaning it is probably a wiring or voltage problem.

 

[walkychalky 10+ year member]

so i ran the amp for a while without rca's n it didnt go into protect....i jus hooked up the first 2 channel RCA's so imma give it a few min n see if it goes into protect b4 i hook the other 2 up

i measured volts at the amp....its about 10.9 DC and 23 AC...same as my 20.1

i have 2 amps turning on with the headunit....i jus have the remote start daisy chained to both amps

 

[mokedaddy 5,000+ posts]

so i ran the amp for a while without rca's n it didnt go into protect....i jus hooked up the first 2 channel RCA's so imma give it a few min n see if it goes into protect b4 i hook the other 2 up
i measured volts at the amp....its about 10.9 DC and 23 AC...same as my 20.1

i have 2 amps turning on with the headunit....i jus have the remote start daisy chained to both amps

10.9 v is pretty low. That very well could be your problem.

 

[jco1385 5,000+ posts]

you only have 10v at the amp? sounds like the problem

 

[walkychalky 10+ year member]

you only have 10v at the amp? sounds like the problem

what should i have?