Amp problem or Pre-Out problem?

[highhpsupra 10+ year member]

I hooked up a new amp recently and when i was setting my gains using the tutorial i was getting 0 voltage on the speaker terminal regardless of how high/low my gain was set. The amp powers up fine and shows 14 volts when the car is running.

I also tried to check what voltage was coming through the RCA's and it showed 0 volts as well. (The RCAs were connected to the rear preout and i was using a DMM on the other end of the RCA cable). I dont know if this is a good way to check because Im not sure if the deck (pioneer 4600MP) sends a voltage to the pre-outs regardless of whether or not its connected to an amp.

PS. the amp is gonna be benched to see if its an amp problem or something else.

any help will be appreciated, if i missed any info, just ask.

thanks in advance!

Click to read more...

 

[djman37 5,000+ posts]

if you got ZERO on the RCA's, it doesn't appear that anything was coming INTO the amp, so I'd check your HU to make sure you had a signal going out of the HU/coming into the amp to start with.

 

[mikeyboc 10+ year member]

Easy way to check is use an Ipod or other portable music player, hook up to the sub imputs with a headphone jack converter and see what comes out. If the amp works, then check your RCA's. But I agree that you should have something coming from the RCA's when tested. Not trying to be a dick, but did you plug them in to the HU when installed?

 

[highhpsupra 10+ year member]

I had the RCA's plugged into the back of the deck from a previous install so they "should" be still plugged in unless they somehow came out. I still gotta check that. Im gonna check the voltage again directly from the pre-out to rule out the RCA cable.

The cables were just sitting loose in the trunk for about 3 weeks after i removed an older amp, it is possible damaged was caused by this somehow?

thanks again for the quick replies!

 

[monkeyboy 10+ year member]

Also make sure you have them turned on. Certain models you can shut off the rear outputs.

 

[Railrocker 10+ year member]

x2 a lot of pioneer decks have the option to turn off the sub output dont know about the rear though.

 

[highhpsupra 10+ year member]

there is no option to turn on/off the pre-out on the deck. so assuming its always on i should get some sort of voltage reading rite?

thanks

 

[monkeyboy 10+ year member]

yes