DRCOFFEE

I am getting a crackle/popping on the FM stations (not AM). I just installed a Kenwood KDC-352U head unit and used an aftermarket connector that has RCA outs for the speakers into the factory amp. If I play around with the wires it will disappear but then come back again. I can't isolate any specific wire causing the noise, nor can I reproduce the symptoms. The first thing I did was to assure a good ground.

I'm trying to understand the wiring. On the wire connector, there are two light blue wires (blue and blue/white stripe) that are fused and go to the amp "on" wire from the head unit. The antenna control wire did not operate the antenna, so I used the amp control wire. What do each of them do? If I disconnect one of them, the antenna goes down. If I disconnect the other, no music plays. That last one baffles me. I thought the RCAs supplied the signal out. It does not seem to be engine whine since it does not change pitch with rpm. But it only happens with the engine running. With motor off the noise is gone. So what is causing this RF interference and why is it sporadic? Is it the power antenna?

Also, I made sure the RCA wires aren't running along the other power wires as well. I watched a youtube video about grounding the RCA connectors to the chasis and that did nothing at all.

Would I be better just deleting the factory amp and run the speaker wires directly from the head unit???

ROCKGUY76

- What year, make and model of vehicle are you dealing with?

- The antena control wire operates your power antena only when the radio is in operation. When your listening to a CD or aixilary input, the power antena will be safely hidden away in your fender. The other blue wire is your amp turn on. It sends a small electrical signal out to power up your amps (usualy 0.5 v). If your power antena is hooked up to your amp turn on wire, your power antena will be up whenever your head unit is on, not just when your listening to the radio. I would recomend hooking these up correctly and testing the power antena to see if it operates properly under these conditions. If not, you would be better off adding a powered and fused toggle switch in-line with your power antena so you can raise it and lower it upon your disgression.

- Will this wiring faux pas ad noise to your system? Ya. Antenas are horendous for noise issues, especially power antenas. An easy way to check your noise problem is once youve corrected your blue wire wiring, unplug the antena from the back of your radio and start the engine and test for noise, both with the actual antena plugged into the head unit and unplugged from the head unit.

- Let me know what happens after thise test and we can go from there.

DRCOFFEE

My truck is the 99 4runner SR5 (in my signature below)

I can give you a partial answer. I disconnected the fuse from the amp turn on lead and the antenna went down. There was no noise but no music either. Which wire is which on this harness? Is the white stripe the antenna pwr or the blue one? having the antenna up all the time is okay but this noise is a problem.

What do those 2 blue wires go to on the factory harness???

ROCKGUY76

Blue power ant, blue white amp turn on, I think....

Having the antena up all the time will eventually cause the power antena to become damage. IE when your trail riding and listening to tunes, the power antena can get bent by branches. Or even in a car wash. Best bet is to follow my previous advice and see what heppens from there. There is no quick fix to solving noise problems, you will need to get your hands dirty and diagnose the problems. Take it one step at a time.

drpdmazda

im assuming you have the jbl stereo in your truck? The solid blue is for antenna and the blue with stripe is for the factory amp turn on. You can bypass the amp if you desire by using a factory non amplified toyota harness and exteding the wires to the radio. But not really needed unless the amp is bad. You can try a "ground loop isolator" it may help mask the problem, but ownt truly solve the issue of where the ground loop is coming from. Make sure your antenna lead is in the back of the radio securely as well, if its loose it may allow in some noise. its possible that you have a low level input amp and the kenwood is putting out high level outputs causing the noise. or vice versa, cant remember the break down at the moment.

DRCOFFEE

The antenna is in good and tight. I've tried separating the wires as far apart as possible but it still occurs. It has to be in the amp connection. I will order up a new harness and delete the factory amp. The next step is to go with a tacoma solid mast and get rid of the power mast.

I have a question about removing the amp. Will the small tweeter speakers on the front door panels still work? I believe I have 6" in the lower front panel and 2" tweeters up by the window. Does the factory amp serarate them or will they still work once I remove the amp?

* I looked at my Kenwood manual and the antenna up lead is "not used" so the amp on lead is the only source I have to energize the antenna.

DRCOFFEE

I just received this response email from a tech at Scosche.

"The harness that is required for your vehicle is just the standard TA02b.

The vehicle has a factory amp that will have to be removed it has 2 connectors that will be disconnected and that is where our connectors will connect to.

The amp will be about 6” into the dash being held by two 10mm bolts remove them then the amp may be removed."

drpdmazda

kenwood has very weak outputs on both their antenna and amp turn on leads. most mazdas do not like kenwoods at all. I would just bypass the amp like suggested in your next post, and you should be able to pick up the standard toyota harness at any wally worl or best buy. if you get a metra harness, its number 70-1761. the tweeters should work with or with out the amp, as i believe they are just in line with the mids, and have a "crossove" on the back of them.

DRCOFFEE

I am still waiting to receive the new harness but do you know what the gray and white wires should be used for on the larger plug?

drpdmazda

grey is front right +
grey/blk front right -

white is front left +
white/blk is front left -

also are you hooking up the orange wire(s)? if so, dont. they are illumination wires mainly used for radioe with navigation screens. Some regular radios do have a dimmer in them, but not many, they all just share the same harness. The illumination wire may be causing some feedback too. leave it disconnected on the new harness, but be sure to crimp it or tape it off as it sees voltage when the truck is on.

DRCOFFEE

The Orange is disconnected. The Kenwood head unit doesnt use a dimmer control.

Thanks for all your help. Its been a good 20 years since I did my last radio install.

drpdmazda

no problem, glad i could help. i forgot that kenwood is one of the few that uses two different style harnesses between single din and double din. And its been about 30 minutes since my last stereo install ha ha.

DRCOFFEE

Well, I switched out the wiring harness and deleted the amp and the crackle is still there. I'm open to suggestions.

rideexileex

iTrader: (1)

By crackle do you mean a distinct popping noise? Or more of a continuous static?

Was this problem present with the factory deck? If not - in perspective of changes, the only thing changed in this scenario was the deck itself. I would say try another deck and see if that is the source of the problem.

DRCOFFEE

its a popping noise that is independent of engine speed but increases with radio volume. Yesterday I bought a mast antenna from the parts store to test the power ant as the problem. What's odd is sometimes its there and other times gone.

I have it grounded to the mounting bolt of the head unit to dash. Should I ground it further away?

Also, I bought the truck with an Aiwa double DIN routed through the factory amp. It did it with that radio as well. So I tend to think the head unit is not the problem. AM is clear and FM has popping. It only pops when the antenna is fully up. Is the antenna grounded in the fender?

Sorry for peppering you with questions. I'm just thinking out loud.

DRCOFFEE

What is this pin wire from the factory stereo? #2 is the antenna. What is #1?

I can see this hanging behind my stereo and I'm curious.