Starting Vehicle Kills Satellite Signal.

I have an interesting problem that i have been unable to find any help with. After installing my Starmate 8 in my 99 Suburban, I get a full meter on the satellite signal meter as long as the vehicle isn't running. As soon as I crank the truck, the signal drops to one bar and then steadily bounces every 1 second between 1 and 3 bars of signal. Back and forth, back and forth and the audio cuts in and out naturally because of the signal drop. As soon as I kill the engine, the signal goes back to full strength. Any clue??? IT'S DRIVING ME NUTS!

Is this antenna run/placed near any other kinds of antennas? I know that placing a satellite radio antenna near another antenna can cause interference and since you're only seeing this issue with the car started, it seems to fit.

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Originally Posted by SiriusBuzz

Is this antenna run/placed near any other kinds of antennas? I know that placing a satellite radio antenna near another antenna can cause interference and since you're only seeing this issue with the car started, it seems to fit.

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Only the radio antenna. Shouldn't be a problem.

It very well could be the problem. The satellite radio antenna should not be placed near any other antenna.

Good thing its easy to test -- just temporarily move the satellite radio antenna few feet away from its current location and start the car.

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Originally Posted by SiriusBuzz

It very well could be the problem. The satellite radio antenna should not be placed near any other antenna.

Good thing its easy to test -- just temporarily move the satellite radio antenna few feet away from its current location and start the car.

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I would doubt it since it works perfectly with the car off and with the key just in acc position.

I wouldn't doubt it.

Once your turn that key and start the car the interference caused by the increase in power from the alternator can do strange things. Fortunately, it only takes 2 seconds to move the antenna.

With this newly added information you provided about on vs. acc, I would make sure the antenna wire isn't running near any major power lines. You always want to run any kind of antenna and audio input as far from power lines as possible.

What year suburban? Do you hear any wine coming through your speakers when you rev the engine?

Quote:

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Originally Posted by SiriusBuzz

I wouldn't doubt it.

Once your turn that key and start the car the interference caused by the increase in power from the alternator can do strange things. Fortunately, it only takes 2 seconds to move the antenna.

With this newly added information you provided about on vs. acc, I would make sure the antenna wire isn't running near any major power lines. You always want to run any kind of antenna and audio input as far from power lines as possible.

What year suburban? Do you hear any wine coming through your speakers when you rev the engine?

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Since my earlier e-mail, I've already moved the antenna to the back of the suburban with the same results.

It's a 99. I hear no issues at all in reception with engine on or off, just that when the engine is on the signal drops and bounces causing the audio to clip in and out.

You have to ask yourself what changes with the car running. The most obvious change is the increase in power from the alternator. With the car being 14 years old, maybe your grounds have gone bad. Im guessing there is some rust kicking around and your grounds are the first thing to fail.

Any aftermarket lights or stereos running on that beast? Again, I would look for power lines near the antenna.

Well I had the opportunity to completely disconnect the alternator yesterday and crank the truck. The issue remains.

Yes this is an aftermarket (brand new) Kenwood I am trying to run it through

So, it works perfectly with the key in the acc position... does it work perfectly with the key in the on position without starting the truck?

Works perfectly in every position until that engine is running.

The only other accessories is a electric brake assist for a trailer, a trickle charger that the previous owner had in it for what reason I don't know and some cheap fog lights (that I need to remove) that were on it when I bought it.

The problem is definitely something cyclical seeing that the signal bounces at a steady rate back and forth. It's not random, but like every second on the second. Weird.

I had a external sat radio in it and thought maybe the radio was bad so I went to Best Buy and bought one of the ones that plugs directly into the new head unit, but the result is the same. So the old external radio has become my test radio. I unplugged the alternator yesterday, plugged in the test radio, placed the antenna on the roof a good 6 feet from the stereo antenna and stood outside the truck holding the test radio and the signal still bounced back and forth. I have a hunch it's the alarm but I can't prove it.

When you tried this test radio did you have the antenna wire loose and running out the door or is the wire run and tucked away near other stuff? If there is nothing near this antenna wire than it isn't the antenna that is being interfered with.

The only other thing I can think of is slight power surges caused by bad ground? Can you power the radio off of something other than the truck but leave everything else plugged in?

If you can plug the radio into another power source and it still happens, its the trucks power source.
If you unplug the radio from sat receiver so that its just plugged into the power and the antenna, the kenwood is the issue.

I'm so interested I want to be there when you walk through the process of elimination. It has to be one of those things. There are only 3 wires and we already know the antenna is good.

Well here's an interesting update. Yesterday afternoon, the alarm started acting up. Would go off for no apparent reason and when I set it, it will wait about two minutes then the alarm will go off, so now I am positive I have an electrical thing going on somewhere. I guess I am going to quit chasing the sat radio issue until I get this alarm ripped out and have the electrical system diagnosed by a professional. No sense in spending anymore energy on the sat radio when I have some electrical ghost in this thing somewhere.

Good luck. Do you know where the alarm brain is?

You could always look it up online and figure out how to disable it for the time being.

Dont forget to check back and share what you found.