no output from amp

[emh9009 199]

so my friend traded some stuff and got a sealed 10" menphis sub and a jensin amp. before he traded it i had the guy install it in his car to mak sure everything worked, which it all did and sounded fine. so he traded and after running wires in my friends car and plugged everything in the power light turns on, but when tested with my DMM there is no output in the speaker terminals... here is a googled page i found on the amp... could the rca's be bad? im pretty sure they are wired right deck is an alpine CDE-102 need any other info just ask... im lost haha

[Tirefryr 1,742]

Just curious, did you have the meter set for AC or DC?

[emh9009 199]

umm.. AC i believe? thought thats what it was supposed to be set at?

[Tirefryr 1,742]

Correct. Pull the RCAs and try to measure them. You may not be able to read it though.

[emh9009 199]

with the same ac setting, when i first touched them it read like .2 and .3 but overall nothing. so does that mean bad rca?

[emh9009 199]

we went and got a new rca, but that didnt help anything. tried a different amp and that didnt even work, but it didnt even have any led to show power or anything. when i try to measure any voltage there is no reading in ac but if i turn to dc i get like 5.6-5.8, what does that mean? think it could be the ground? its on bare metal with same gauge wire as power (cut from same strand even..) the deck is brand new, so im completely out of ideas.. anyone? :S

[Estsound 7]

try another hu.

[emh9009 199]

ouch, we dont have one of those readily laying around haha i think he is taking it into the local shop to have them check it out tomorrow, hope that helps him out...

[Estsound 7]

well if RCA cable is working and amp is working, its only thing to check i guess.

[emh9009 199]

epic fail on my part... bad ground. but i really dont see why, it was on bare metal and it was a solid connection. but i guess im still learning. the local shop just drilled a hole and put ground there and it works. are some metals better gounds than others? or would it be that it wasn't directly connected to chasis? im not sure if it was or not i coulnd't really see, but it was close to it so i figured it was.

[fuggles 0]

live and learn. that's why i like to do my own work. failures are the best teachers. definitely not all metal is connected to the chassis. voltage measurement would tell you.

kent

[Duran 387]

epic fail on my part... bad ground. but i really dont see why, it was on bare metal and it was a solid connection. but i guess im still learning. the local shop just drilled a hole and put ground there and it works. are some metals better gounds than others? or would it be that it wasn't directly connected to chasis? im not sure if it was or not i coulnd't really see, but it was close to it so i figured it was.

That's not good enough, if they just drilled with a self taping screw it won't hold for long.

[emh9009 199]

i haven't seen it yet, my friend just called and told me what they did. but knowing them, im sure thats what did go down. i think thats what i have in my car, actually. it has been holding on for.. a year now? but im getting a new car soon so ill be doing this all again in a couple weeks. tips on grounding? do what the shop did, except with a nut on the bottom holding it tight?

edit: question just popped up about the next install. i have a 100.4 and a 1500d. should i have seperate ground points, or would it be safe to put them on the same one directly on chasis?

Edited August 29, 2009 by watts09

[Duran 387]

i haven't seen it yet, my friend just called and told me what they did. but knowing them, im sure thats what did go down. i think thats what i have in my car, actually. it has been holding on for.. a year now? but im getting a new car soon so ill be doing this all again in a couple weeks. tips on grounding? do what the shop did, except with a nut on the bottom holding it tight?

That's exactly what you should do