Alpine mrp-m850 will power on but no power to sub

[justin151]

Ok first of im new to this site so dont hate on me too much.

I just bought the amp off a guy locally and went to hook that amp up to my Kicker s10l7. Once i got everything hooked up the amp would power on and i get the blue LED on but nothing comes out on the sub. I had a kicker amp installed right before i hooked this one up that had no issues at all. Now i took a multimeter and checked just about everything. I have 14v of power going to the amp. The remote wire has power and I have the amp selected on on my head unit. I also checker the output on the amp but now this is where i got confused. I have nothing showing coming out on multimeter with both pos and gnd hooked into the amp but if i just put the pos in and touch another ground point the VDC ranges (only playing a normal song) from 25 to 30. So i am not sure if the gnd transistor is blown on the amp or what?

Does anyone have any ideas what else i could check?

I dont think it is the sub cause its a dual 4 ohm wire down to 2 ohms to the amp. i double checked all the wires on it and it all seems good.

I appreciate all the help and input anyone has to offer.

One more thing does anyone know of any places in tn i could get the amp repaired if needed or anyone that would do it for cheap and fast? I am getting ready to deploy to afghanistan in two weeks and would like for it to be done before i leave.

Thanks,

Justin

Click to read more...

 

[keep_hope_alive Premium Member]

you want to measure VAC out of the amp between the terminals - you shouldn't have any DC voltage going to the sub. measuring DC voltage between outputs and chassis is just an issue of relative voltage.

verify a connection didn't come loose during the swap - measure resistance at the speaker wires before they connect to the amp.

call Alpine for the nearest service center - you'll have to ship it to them and it will take them a month or so (typically).

good luck in Afghanistan - and thank you for serving our country.

 

[keep_hope_alive Premium Member]

on the head unit - do you mean you turned on the subwoofer output and turned up the sub level control (assuming you have that feature)?

gain is properly set? crossover is properly set?

 

[justin151]

Hey man I appreaciate the help. I feel like an idiot though lol. I double checked in vac and it was working fine so I chase wiring on the sub itself. The wire splices I had were junk and didn't have any connection. The sub works great now just gotta tune up the amp. I'm so glad I don't have to drop a bunch of money to get it fixed. Thanks again for the help and the good luck.

Justin