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Discussion Starter #1
I have a Pioneer car stereo and it sounds fine in FM. When I play a CD or connect my IPod the loud random pop noises start. It drives me nuts. I also have an MSD ignition but the pops don't equate to rpm or anything. They are just random. If I disconnect the antenna the same noises happen. I suppose the antenna input picks up the noises then. I have my battery in the trunk and the large cables run down by the passengers feet in the corner along the door jam. I suspect my MSD box which is mounted on the passenger inner fender close to the heater motor. Any ideas? Thanks.
 

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If it works fine in fm no trouble at all. It might be the deck.
If you have an old head unit around switch it out for a couple days . If I works fine then you know it the deck.
But if it does the same then you have other issues.
 

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I have a Pioneer car stereo and it sounds fine in FM. When I play a CD or connect my IPod the loud random pop noises start. It drives me nuts. I also have an MSD ignition but the pops don't equate to rpm or anything. They are just random. If I disconnect the antenna the same noises happen. I suppose the antenna input picks up the noises then. I have my battery in the trunk and the large cables run down by the passengers feet in the corner along the door jam. I suspect my MSD box which is mounted on the passenger inner fender close to the heater motor. Any ideas? Thanks.
Like funnytoe said, I would try a new head unit before I start messing with wires or anything.

If not the head unit, sounds a lot like a bad ground to me. When I used to install stereos in older cars, I would notice the same things.Are you using the original wires?

Run a temp wire from the fuse box and as short of a ground wire to the chassis as possible, see if it clears up. Wires will pick up a lot of induced noise on long runs
 

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My vote is "a loose groung connection someplace". You didn't specify if you are running amplifiers. Do you have this issue when the ignition is off and the car is just sitting?
 

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Discussion Starter #5
No pops with engine off

My vote is "a loose groung connection someplace". You didn't specify if you are running amplifiers. Do you have this issue when the ignition is off and the car is just sitting?
It only does the loud pops when the engine is running so I know it's related to the charging circuit or MSD ignition somehow. I picks it up when I disconnect the radio antenna too so it is some EMI from something. I've grounded the stereo and all wiring is new. I have no amps just the Pioneer stereo with 4 speakers. Thanks
 

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Discussion Starter #7
Plug wires arcing

What about grounds in the engine compartment? No issues with spark plug wires arcing?
I took a close look at the MSD wires for any arc jumps in the dark and I found nothing. I've got them pretty well loomed but some come close to the cowl but I've never seen any leaks. I've got a ground strap from engine to front clip TCI chassis and a ground on the (-) battery in the trunk to the body. I tried an extra ground to the stereo's aluminum case from a stud for the rear support. No difference. I'm about ready to build a grounded shield for it. So in summary; no noises with engine off, no noises on FM, but pop noises with antenna disconnected, or cd playing or IPod connected. I think I'll take it down to a car stereo install place and see what they say about it. Wish me luck.
 

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I have an older pioneer head unit in my 74 I just bought. It does a lot of popping, but only when there is a good amount of bass and only on cds. I think it does this without the engine running though, I'll have to check. Sounds to me like it's just an issue with these pioneer head units. I'll be tossing mine aside anyway for an under dash 8-track player so I won't really be looking for a fix though.
 

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I'm about ready to build a grounded shield for it. So in summary; no noises with engine off, no noises on FM, but pop noises with antenna disconnected, or cd playing or IPod connected. I think I'll take it down to a car stereo install place and see what they say about it. Wish me luck.
Years ago I had problems with the Ford trucks getting induced noise into the radio chassis and by wrapping the chassis with an insulator and then fabricating a tin box to go around it, then insulating this and adding a second box the induced noise got blocked.
When I was troubleshooting it we could pull the radio out of the dash and the noise would go away and then the closer it got to being mounted into the dash cavity, the worse the noise got so we knew it was an induced noise signal. There was a fix at the time and by relocating the offending wires in the harness you could get the same results but since the vehicle was new at the time we didn't want to take any chances of voiding the electrical warranty.

I wonder too if there is a way to make shorting or shielded ends for the RCA connections as maybe they are picking up an induced noise. I know on splitters for cable systems you cannot leave unused taps uncovered.

Jim
 

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Discussion Starter #10
Open RCA inputs

Years ago I had problems with the Ford trucks getting induced noise into the radio chassis and by wrapping the chassis with an insulator and then fabricating a tin box to go around it, then insulating this and adding a second box the induced noise got blocked.
When I was troubleshooting it we could pull the radio out of the dash and the noise would go away and then the closer it got to being mounted into the dash cavity, the worse the noise got so we knew it was an induced noise signal. There was a fix at the time and by relocating the offending wires in the harness you could get the same results but since the vehicle was new at the time we didn't want to take any chances of voiding the electrical warranty.

I wonder too if there is a way to make shorting or shielded ends for the RCA connections as maybe they are picking up an induced noise. I know on splitters for cable systems you cannot leave unused taps uncovered.

Jim
Good idea Jim. I'll take some of those RCA plugs from an old home stereo receiver put them in and see if that makes a difference. Worth a try, thanks. Ken
 
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