Team Chevelle banner
1 - 8 of 8 Posts

·
Registered
Joined
·
723 Posts
Discussion Starter · #1 ·
I installed a new CD player\radio in my 65 chevelle. I noticed that the sound cuts out for a second or 2 when I put the car in gear (automatic) or when I press the gas to begin takeoff. It also did it a couple times when driving in my driveway at low speed. I tried changing the ground wire many times, to different locations. No change. I removed the original external volt regulator and alternator and upgraded to a 12SI unit. No change, same cutting out problem. I emailed the manufacturer of radio and set out the symptom. A tech responded by saying I may have too much voltage going to radio so it is shutting down. He asked me to check the voltage at the radio wire. I will do that tonight again. I recall doing that quickly last nite--I got 14.6 volts across the battery posts when car was running, I got 14.6 volts at horn relay junction block, and I got 14.6 volts at the fuse box in the car where I plugged the radio wires into. Not sure how accurate my voltmeter is though.
Q. is 14. 6 too high?
Q. if so, how do I reduce this voltage going to the radio? (not sure how much I need to reduce to?)
 

·
Registered
Joined
·
4,547 Posts
Those voltage readings are normal. Really sounds like you have a poor connection somewhere, either on the power or ground side. Check all you connections (connections should be soldered) and if you are using plug in connectors, make sure they fit tight.
 

·
Registered
Joined
·
723 Posts
Discussion Starter · #3 ·
thanks Greg,
did another voltage test last night. Got 14.18 on the ignition spade in the fuse box. But noticed that when I depress the brake and put car in gear, voltage on that wire drops to 12.8 momentarily and jumps to 13.8, then eventually gets back to 14.2 as car moves. This seems normal to me, but my radio cuts out when the voltage jumps that one volt. I can make the radio cut out every time by holding the brake, car in gear, and pressing gas slightly.
Should radios be able to take this 1 volt jump? I would have thought so, but the manufacturer is presently blaming the car.
 

·
Premium Member
Joined
·
512 Posts
Good radios should have voltage regulation inside. Does it go out in CD and FM ? Cd takes more current.Is this a cheepe radio or good stuff?. I am leaning toward the radio being at falt. Gary
 

·
Premium Member
Joined
·
4,476 Posts
I'm gonna have to agree w/ Gary. A GOOD radio will accomodate fluctuations in system voltage. I've got a Pioneer AM/FM/CD in the box at home (will actually be used for a home project--I WILL NEVER CHOP MY DASH!!!!) and if recall the mfg. has a range of voltage input--down to 11.5 if I remember right is acceptable.

SO, 1) either your system voltage is falling, and your meter may not respond fast enough, even if it is digital, there could be a "low spike" or a very, very short duration in which the voltage may fall to let's say the high side of 10 or low side of 11.XX volts.

2) Your radio is not up-to-snuff. Personally I'd be a little disturbed by a technical assistance guy who says your voltage is too high at under 15 volts.
 

·
Super Moderator
Joined
·
13,311 Posts
But noticed that when I depress the brake and put car in gear, voltage on that wire drops to 12.8 momentarily and jumps to 13.8, then eventually gets back to 14.2 as car moves.
This should not happen. You have a bad connection somewhere, either ground or power. Try running your power wire directly to the battery for a test and see if it solves the problem, if it does, then you know your connection problem is on the power side. Or just have someone stand to the side of the car with a volt meter hooked to the battery and watch it while you put the car in gear.

You said that you have the power "plugged in" to the fuse box ? What did you plug it into ? Also, where is the ground wire attached and how ? Sheet metal screw, forget it. Needs to be a ring terminal bolted to the dash support where the rest of the grounds go. Also, is the body ground wire from the battery negative terminal attached real good to the fender ? Take it off and clean it and the fender real good.

My money is on a bad connection.
 

·
Registered
Joined
·
723 Posts
Discussion Starter · #7 ·
Thanks guys,
The radio tech guy now says the unit should handle that kind of voltage fluctuation. He concludes the unit is bad, but tells me to go to the vendor to get a new one, not his outfit that manufactured it. Runaround begins.
Unfortunately the unit is not name brand, it is Boss Audio out of California. I bought the unit because it is a marine stereo with wired remote. I couldn't find a reasonable price wired remote locally near the price. I put it in the glove box and used their long cable under carpert to put a small remote unit beside the drivers bucket on the rear of console. Works so nice with the remote, I can control most everything at my fingertips yet keep the stock parts.
The ground wire is on a ring clip bolted to the heavy dash brace. I even ran a second ground wire from the dash brace to the ground post on the rad support. No change. I may test voltage tonite at the main junction block under the hood to see if voltage varies from 12.8 to 13.8 when car is in gear, foot on brake, etc. Last nite I got 14.2 volts there but I only tested at idle without putting car in gear, brake on, etc.
I will report back.
 

·
Registered
Joined
·
723 Posts
Discussion Starter · #8 ·
To add to the above, it is not the drop in voltage that seems to cause both the radio and CD player to cut out momentarily, it is the move up in voltage from 12.8 to 13.8. As I say, it usually plays fine when I put car into gear and foot on brake, but if I press the gas peddle and increase rpm a bit, the voltage goes up on the line and head unit cuts out. (Altho one driving on my driveway in gear it cut out for a second).
Anyone know what a good radio has inside to withstand minor volt fluctuations?
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top