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Are we the only ones with GPS car charger failures?

Posted by Bhamster (My Page) on
Fri, Jun 15, 12 at 13:06

We bought a Garmin Nuvi 205 several years ago--just wanted a basic gps for directions. It hasn't been very good at finding things (like Mount Vernon on a recent trip!) but the main problem is that we've just had the 2nd car charger fail on us. This one only lasted 2 months.

Since newer Garmins still appear to have the same kind of car charger, we're reluctant to buy another--but when you check ratings, the Garmins are always rated the best. We can't find anyone talking about the failure of the car chargers.

Any recommendations for a lower-end GPS that will actually know where Mount Vernon is AND has a reliable car charger?


Follow-Up Postings:

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RE: Are we the only ones with GPS car charger failures?

Yes. U are only person on earth with a bad car charger.


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RE: Are we the only ones with GPS car charger failures?

It may not be your GPS charger, but could be the electrical system in your car. There are occasions when voltage spikes up 70 V have been recorded on 12 VDC auto systems. These spikes can kill unsuspecting electronics. One such event is stasrting the engine. Very large amounts of current is drawn by the starter and when this circuit is itgerrupted, large voltage spikes can occur in the power circuit between the solenoid contact and the starter motor. Normally, this does not get out into the general curcuits, but if someone has connected a lead to the starter solenoid terminal, it could be a problem. These types of voltage spikes are of short duration, and where they have found to cause trouble, a bypass capacitor may have been added to the system. Sometimes, the bypass capacitor fails or is removed when changing a component such as a starter motor.

A second source is he starter motor itself. When the engine starts and the strater motor is still engaged, it can be spun by the engine past the speed where it becomes a generator and gives the electrical system a shot. You will note that car radios are powered off when the ignition key is turned to the start position. This done partly to maximize power for starting, but more so, to protect the radio from starting transients.

You may have one or two power outlets in the cabin. One may be for a cigarette lighter and the other for accessories. The lighter socket may be hot at all times and is not a transient protected circuit. It is 'hot' with the key off. The accessory socket may be protected and may be off when the ignition key is off.

Late model cars may dispense with the lighter socket and have only an accessory socket.

What to do: Attach an oscilloscope to the power source you are using for the GPS unit and test for transients bwteen this source and vehichle ground. If you find transients more than 1.5 times system voltage, then snubbing is needed to protect your electronic accessories.


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RE: Are we the only ones with GPS car charger failures?

Jem:
If I follow your post, the suspected spikes occur priamarily when the car is started. If the OP just constantly leaves his GPS plugged in, then this might be his problem. The simple solution is to unplug the charger except when he wants to use the GPS and only plug in the charger after the car is already running.

Just a thought. Not every one has an oscilloscope and knows how to use it.


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RE: Are we the only ones with GPS car charger failures?

Brilliant, Jemdandy! Makes a lot of sense. We had a Sirius player plugged into the accessory socket and so always used the lighter socket for the GPS. Now that we've gotten rid of Sirius, we've still been using the lighter for GPS.

I had been reluctant to buy yet another car charger for the Garmin but am willing to try the experiment and only plug it into the accessory plug and/or make sure to remove when starting.

Very grateful for the info.


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RE: Are we the only ones with GPS car charger failures?

Be sure to use an LED oscilloscope. :-)


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