Hi gang, I recently purchased a used RF 800A2, did a temp install just to get the beats thumpin, all worked well for a week, then it started shutting off on me, now I can't get it to come on at all. I have my doubts that its an amp problem since the guy I bought it from has had it for 3 years and I've known him longer than that, plus it worked great for a week or two.

In trying to diagnose the problem, (on advice from the manual for the amp) I started measuring voltages, I've got a good 16 V when the truck is running from the bad and to the amp, but if I measure accross the +ve and -ve terminals of the amp it only gets about 10 V, which it says in the rockford manual should be 10.5-15.5, so I suspect it may be a bad ground, any thoughts?

dont measure across the terminals u will get a gay reading. measure the wires. yes bad ground would make your amp act like that.

[ September 08, 2004, 08:03 AM: Message edited by: Father Yuli ]

Yea, sounds like it could be... make sure the connection is solid with bare metal/metal contact... If that dosen't do it, go over all the wiring and make sure it's good...

I wish my car made 16v while running [img]graemlins/headbang.gif[/img]

Thanks guys, here's what I did, I measured across the terminals (should act same as the two wires at the terminals, just easier to get the probe on) and got 9-10V, then kept it to the +ve terminal and picked a different ground and got 16V.

It seems odd to me though that it would work good for a while, and then crap out :S you'd think if it was bad it would have been bad all along, no?

[ September 08, 2004, 08:13 AM: Message edited by: Vanilla_Gorilla ]

I had a ground that work gret for a month then got noise in the system ooked at the ground and there was white crap built up around it. Macke sure it is on bare metal and tight.

Then coat both side w/ grease or paint or liquid tape to keep moisture out.

Grounds are one of the things that need regular attention. 3-4 times a year a person should clean their battery terminals, check that the water level in the battery is topped up, make sure all power connections are tight, and that grounds are all clean and tight.

I see people change batteries all the time when cables and terminals jsut need to be cleaned/tightend. They make cleaning and protecting sprays that work well.

if you have less than optimum voltage the chances are it could be your power or your ground
you need to eliminate one to say its one or the other
not to be i see to many posts that everybody jumps on and say oh its this or that
you must eliminate one before calling it


so to do this you need your amp on driving a volume to load the amp

now check the voltage at you battery terminals
now put your probes on the power terminal and and one on your amp terminals
is the voltage close to your batterys?

now find a piece of metal that you can clean off and optain a descent ground close to the amp
now put your probes on the power terminal and one on your other ground
whats your voltage there?

Here's the sequence I used to test it, truck running amp not not b/c it isn't working, hence this post ;) :

1. Measured Voltage accross +ve and -ve terminals of amp, readings were 9-10V.
2. Measured Voltage at the battery, 16 V.
3. Measured Voltage after under hood fust, 16 V
4. Rechecked volatage across amp terminals, 9-10V
5. Checked voltage from postivie terminal of amp to alternat ground, 16V.

Hence my question about the bad ground causing my amp to keep quitting occasionally to the point it won't turn on now. What got me thinking to check was the rockford manual saying the amp won't turn on with less than 10.5 V.

so what is your voltage from your amp terminal to a clean ground yoou just made?

I never got a chance to re do the ground last night, but to an alternate ground in the cab I got 16 V

yes a bad ground will cause the problem you had/have

WELL... I took the rear seat out last night (where I have my ground going) and ground down around the hole to bare metal, hooked my ground back up, put the seat back in and all seems to be fine, for now :confused:

Just wanted to say thanks to everyone for their input, graetly appreciaed!!!!!!! [img]graemlins/thumb.gif[/img]

[ September 10, 2004, 05:26 AM: Message edited by: Vanilla_Gorilla ]