I know this is off topic, but I have hard wired my navigation unit (tomtom go 300) in my maxima to the fuse box using the car charger and now the unit is not working. I think its fried due to too high of voltage. But when I tested the voltage, it reads as 5.20 volts and the unit is a 5 volt electronic. If 5.20 volts are going into an electronic that needs 5 volts, will this be enough to fry the circuitry inside the unit??? The installer at best buy who hard wired it for me said that it is not enough to blow it, but I dont know if this is true.. Does anyone know???

 

I think it might... It might have fried it when you crancked your car, i believe the voltage jumps above that mark, so it could have spiked it out. But dont take my word for it..

 

Nope, it's not possible for your system to burn a fuse if you're getting 5.20v. Most everyday-use systems have a voltage tolerance of +-5%, so it will work fine with 5.25v or 4.75v, altough it's not recommended. If we were talking of a military or medical grade equipment, the tolerance is +- 2%, and then it could be an issue. Maybe your gnd is not stable or hooked up right, or the current pulled by the navi system is too high. If that's the case, you have a faulty circuit on you add-on, not on your car.

 

Well I know this is gonna be moved in a minute, but I have a question...

You said you hard-wired it using the car charger... I'm guessing the unit itself uses 5v and you're talking about some kind of transformer that shipped with it or a plug to go into a power outlet in the car?

If you just cut the wire up to the plug and wired it straight to the fuse, you might have left behind more than just the plug... most of the units that get juice directly from the car will have a regulator somewhere along the line to manage the spikes in the car's power supply, especially during crank.

When did this stop working exactly?

 

No, there is some other problem 5.2 volts is not too much.

 

I don't think it fried it, voltage does fluctuate and appliances and equipment have a fair amount of built in tolerance to counter, however big spikes (definitely higher than a .20) like 10-50 volts will do damage, also normally something that is fried will have a slight burnt smell about it. That's why everything at my house has a surge suppressor or voltage conditioner!

Your unit may have been faulty before installation, (defects happen!) at any point, was it ever operational???

 

Thanks for all the information. Let me add some more details about my situation.

Obviously the car voltage is 12volts, and the unit accepts only 5 volts. So the car charger that came with it has a converter inside the plug that reduces the voltage from 12 to 5 so that the unit will accept it. So when I hard wired it, I did not cut the plug off. I plugged the car charger into a socket that I bought from radio shack, and then the socket was then connected to the fuse box so the voltage remains at 5 volts. The reason I feel that the voltage fried it is that I had the same situation with another unit in the past where I DID cut off the plug on the car charger and wired it directly to the battery and I put 12 volts into the 5 volt unit. Stupid me, I didnt even realize the plug had a converter in it and that it was necessary to be kept in the circuit. But I then changed the wiring and kept the plug on and yet the same situation seems to have happened. But the problem is that the voltage is 5.2 this time and if this is not enough to fry it, what could have caused my unit to not work? I turned the unit on and put in my address that I was driving to, as soon as I placed the unit onto its dock (which is also connected to the power cable) the unit froze for half a second and then shut off and never turned back on. What could it be??

 

Is there a reset?

 

yes there is a master reset on the unit but it doesnt do anything when I push it

 

Machinist, you're a genius! I just tried the master reset again but this time I held it down longer. I then plugged it into the power and it turned on!!! Thanks for reminding me again about the reset because that made me want to try it again!!!!!!!! Problem solved guys!!! However, I still do not know what made it shut down in the first place, but I hope it doesnt happen again! Thanks everyone

 

Glad to hear its working

 

When you say car charger, do you mean cigarette lighter plug? Those are almost always fused internally... in case you ever find your unit not working again.... Glad you fixed it.

 

Yes I do mean the cigarrette lighter plug. But that was still working even though the unit itself was not