I see a rash of these car threads right now so whats one more…um, right?
I have a 99 Olds Alero 3.4L GLS. I stopped into Circuit City/Firedog (I know, bad idea) to get a RF Modulator installed behind my GM factory stereo so that I can pump my iPod/Zune directly through my speakers. This turned into a complete fiasco and a waste of 3 prime boozing hours. Anyways, I’m curious if you folks can come up with a hypothesis of what the problem was or if the Firedog guys screwed something up.
Here’s the problem as the Firedog guys explained it. Every time they connected and switched on the RF modulator it’d immediately drain the battery and throw the voltage into the negative. They recharged the battery and retried the connection with a different part and the exact same thing happened. The car would start fine and charge up but the second that the Modulator was plugged in the lights in the car would dim and in minutes the battery was wiped out.
This sounds like it’s almost certainly a short, but I can’t understand where it might be. Everything seems perfectly kosher now that the part is gone and things were fine beforehand but they tried two parts and it seems somewhat unlikely that both were defective. I’m at a loss to understand what about a RF modulator could create a compatibility issue, but that seems to be the case if we assume that the 2 parts weren’t both defective.
I’ll add this one caveat. About 2 years ago I had a enigmatic electrical problem that precipitated a new battery and a new alternator. The mechanic never seemed entirely confident on what the problem was and 3 repairs and 2 tows later it seemed to be fixed. We chalked it up to a bad part combined with a bad connection but it seems to have been working mostly fine since. I say mostly because in my work I would often have my hazard lights while double parked or in a loading zone and I’ve noticed that the battery seems to run down really quickly when I do that. There have been a couple times where I needed a jump start after only 15-20 minutes of having the hazards on. There have also been a couple occasions where while driving the car will hesitate on acceleration and the gauges would spaz out, but thankfully after laying off the gas and letting it idle for a couple moments everything would work out fine. Thats only happened perhaps 3 times in 2 years so it’s far from common. Long story short I have a slight paranoia that my electrical system has some gremlins that could be the root cause of all these issues but I have no idea how to find out if this is the case.
Any ideas? Seen this before? Know anything about hooking up a RF modulator to a GM factory stereo?
Car batteries have enough energy in them to run your headlights for hours, and still be able to start the car. Unless this RF modulator needed an FCC license to operate, it couldn’t possibly be drawing more than a few tenths of an Amp, which means it should be able to run off of the battery all week. If it was truly draining a fully charged battery in seconds, I would expect it to have blown a fuse, or melted wires behind the dash.
My guess is that the guys who installed it are morons.
Of course, if this was an Illudium Q modulator, that could explain it.
There are a few things about your OP that don’t make much sense
Umm this isn’t possible. If the accessory dropped the voltage in the battery below about 10 volts the car would shut down. Once you drop to about 10 volts the onboard computers go into standby mode, and stop working. No computers, no car. Once the battery hits zero that is as far as it can go. It can’t go the other way. Did you mean the charging system was discharging? This is possible but you would only know this for a fact if your car has an ammeter or the firedog guys had one.
It doesn’t sound like a dead short, but it does sound like one hell of a draw. Ded shorts have a bad habit of blowing fuses or burning things up.
I suspect the following:
Your alternator is not working up to snuff, and while it can barely deal with the everyday loads on your car. It is not fully charging your battery. Adding the additional load of the modulator is the straw that is breaking the camels back.
Also I suspect that your battery is either bad or seriously undercharged.
I would suggest that you go to a shop that can do a full electrical diagnosis and have a battery load test, alternator output test, AC ripple test, and a starter draw test done. Sears for example does a very good electrical system diagnosis, if you don’t have a regular mechanic that has the proper equipment.
Oh, and yes you can get two dead units in a row off the shelf. Particularly if you are using an after market accessory. You car might be configured different, and the accessory maker did not realize this and it does not work in your car.
Once you get the electrical system straighten out, go visit Crutchfield they have vehicle specific adapters for iPods in your car.
That’s an Illudium Q36 explosive space modulator
:rolleyes:
Sheeh, get it right would you?
::: Looks over at Marvin statute on corner of Rick’s desk:::
Mind you that my brain wasn’t fully engaged when they were explaining the issue so it’s very likely that something was misunderstood and/or communicated badly by them. I gather that all of this was happening while the car was turned off. They presumably had an ammeter and/or volt meter attached to the battery, alternator or some other measuring point while the car was not running but the accessories were on so they could run the radio/modulator. The key point was that whenever the unit was connected the car would not start. Then they’d recharge the battery and start the car, then connect the modulator which would kill the battery before it would be able to restart again. Rinse, lather, repeat.
Long story short, they did have equipment to measure some of the amp and volt outputs and presumably knew how to use them even if they weren’t able to explain it so I’d understand.
Would you mind distinguishing the two? I always assumed a short was a short.
I agree that there is likely a larger electrical issue, but if it is a straw breaking the camels back type thing I would have assumed that the problem would have cropped up a few hours later as it slowly over drew the system. The Firedog guys were pretty clear that it was a basically sudden cut and dry reaction. Would that immediate dead battery be caused by a scenario like that?
One detail that I left out of the original story is that somehow during this procedure my fuel gauge got pegged to the point that it hung up on the top side of a peg well over the top of the Full marker. They didn’t access the dials at all so my presumption is that when the electrical system spazzed out the indicators reacted so dramatically that the momentum carried is over the top of that peg. The net result is that I’m going to have to have it taken to a dealer in order to get that fixed. While there I’ll ask them to do a full electrical analysis. It’s safe to assume that the dealer will be able to thoroughly investigate this I assume, even though Oldsmobile has been discontinued? With a little luck the Firedog Insurance (which they promised will pay for the fuel gauge repair) will cover the electrical diagnostic too since they were tinkering with it.
