Amp shutting off !!!

[Louisiana_CRX 5,000+ posts]

Here is an odd one...I have a friend who has an older chevy extended cab truck...the one with the two piece radio....He come by and told me his amp was cutting off...when he turns it up...It is running a pair of 6x9's a Kenwood 2 ch. ...So I do some test on the amp with DMM all voltage readings are fine....he turns up the volume on the radio (basic Pioneer CD) and there is a big voltage drop on the power wire...That is when the amp shuts off...So I'm thinking maybe a bad gnd...so I run a wire from the gattery gnd to where the amp is grounded and it is a good low resistance gnd....So then I try another test...I touched the pos and neg leads on the post and read them with the meter 12v's or so but when he turns up the radio it drops between the post of the battery just like on the amp....I'm thinking a bad battery ...but I'm not sure...has anyone seen this before or have any solutions? There are no subs in this truck just an amp maybe 75wpc....but probally less on the 6X9's. Thanks...Dave

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[dleccord 5,000+ posts]

any update on your friend's chevy? can you explain what a two-piece radio is? doubt it's a bad battery or else it wouldnt hold charge, right? did you check his remote wire from the deck itself? good ground huh, how bout power wire? bad amp maybe? iono, check those things and get back

 

[supa_c 5,000+ posts]

2 piece radio is the old 1989 chevy trucks with the retarded h/u in the dash and the tuner lodged inside the dash in another place and the radio mounted in the lower dash. Its not your normal h/u, doesnt even have a mounting style.

What does the battery float at ?

Might want to get the alt tested as well

 

[dleccord 5,000+ posts]

so it's not your regular din size?

 

[supa_c 5,000+ posts]

Stock, no

But they make a kit that moves it to the lower section of the dash for a regular DIN mount.

http://cgi.ebay.com/ebaymotors/1988-1994-CHEVY-SILVERADO-GMC-TRUCK-RADIO-COMPLETE_W0QQcmdZViewItemQQcategoryZ38639QQihZ002QQitemZ120036703494QQrdZ1

Crazyness yo

 

[dleccord 5,000+ posts]

thats gon be ugly.

 

[bri487 5,000+ posts]

so it's not your regular din size?

on the big square instrument panel to the right of the gauges, the stupid box that they call a tuner is there above the a/c controls, and directly in the middle of the dash is the tape deck. you have to mount an aftermarket deck in the tape decks spot, single din hole, but the dash kit comes out like an inch and a half or two inches because an aftermarket deck is too deep and will hit the a/c ducts, so it sticks out and looks bootleg.

http://www.xmfan.com/files/3201_1052326830.jpg

 

[Louisiana_CRX 5,000+ posts]

Yeah thats what I mean by he older 2 piece radio...A tuner in the dash...sometimes a cassette or pocket in the center....A sorta pain to do an install in but not to bad once you've done a couple....

What is odd about this the battery floats fine at 12.7 or so only when you turn up the amp...the voltage drops to like 9-10 volts...when reading across the neg and pos battery post...This is not a high current amp by no means and only running a single pair of 6X9's .It plays fine at low volume...only goes out when the voltage drops..... Maybe something in the amp is bad to make voltage drop like that...all the other wires check out fine...and it has a very good ground...that was checked as well....

 

[bri487 5,000+ posts]

Yeah thats what I mean by he older 2 piece radio...A tuner in the dash...sometimes a cassette or pocket in the center....A sorta pain to do an install in but not to bad once you've done a couple....
What is odd about this the battery floats fine at 12.7 or so only when you turn up the amp...the voltage drops to like 9-10 volts...when reading across the neg and pos battery post...This is not a high current amp by no means and only running a single pair of 6X9's .It plays fine at low volume...only goes out when the voltage drops..... Maybe something in the amp is bad to make voltage drop like that...all the other wires check out fine...and it has a very good ground...that was checked as well....

thats common with those cars. had to do an alternator on the old burban.