TomTom wont work when i switch ignition of car on?

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Mar 16, 2011
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Can anyone help i have a tom tom one xl works perfect outside car ,but when i turn ignition on i keep on losing satellite signal,i have a renault clio car van, and have updated software also to latest so i know its not tomtom but some sort of earth or something affecting signal but cant work this out ?has anyone had a similar problem or knows anything about earthing maybe? not sure ?:confused:
 
Welcome to TTF.

Others with much more knowledge will hopefully jump into this thread but I do know that when you first turn on a tomtom unit, much of the processor is utilized in capturing a gps signal. That, in turn, puts a strain on the battery for a few seconds.

Well, if somehow the combo of your unit with your charger with your specific car is such that not enough juice is going to the unit from the cigarette outlet, maybe the battery is under strain to maintain the processor which, in turn, affects the gps capture???

As I said, hopefully someone will come along and say I'm nuts and give you a proper response. :eek:
 
The first thing I would suggest is to try it, in the car, in exactly the same position as normal, but without the car charger.
If it behaves just as badly while on battery power, then it's nothing to do with earthing.

Next, if you can wave it around inside and then stick it out through an open window and the signal improves dramatically, then it sounds like you have a heat-reflecting coating on the windscreen which can badly affect signal strength on older models (but the GPS chipset in a One XL is usually pretty imune to that as it is much more sensitive).
 
tomtom wont work when i switch of car ignition off?

hi thanks for comments ,andy i have a heat-reflecting coating on the windscreen on my renault clio car van...i have just put tomtom inside without cig charger,and it works fine also outside car works fine but even if its in car or close outside car as soon as i turn ignition key on the signal stops on tomtom ??........my mate and i have tried putting out window inside without leads but as soon as ignition turns on bang goes signal ....thats why i thought earthing or something just paid ?150 for tomtom with latest maps software as well?...theres got to be a way around this!!:confused:
 
So with the TomTom working on battery power, if you turn on the ignition, the signal dies?

Has to be some massive interference being radiated by something in the engine!
 
tom tom wont work when i switch on ignition?

you siad "Has to be some massive interference being radiated by something in the engine! " what could that be ??? electrical?i really dont know where to start with this one thing is i really need to have tomtom working too?:confused::confused: i would be grateful for any suggestions ?
 
tom tom wont work when i switch ignition on?

Andy "So with the TomTom working on battery power, if you turn on the ignition, the signal dies?" YES.....:( thats exactly what happens
 
dcdd1 - as you have suggested - you have a 'earth' or ground problem.

You should check (remove, inspect, clean); any ground straps on your vehicle. This actually probably won't fix the problem. But, at least your checking the grounds.

You might also have a bad Radio Frequency Resistor. Which is used to help keep out high frequency energy noise from the radio.

Vehicles generate a tremendous amount of high frequency noise. This is caused by the NUMEROUS sparks or arcs of the spark plugs. We also now have a vast array of induction coils, and IC circuits - to run various computer controlled engine components.

Did you purchase this vehicle new? Are you familiar with the maintenance history, etc? A bad ground can cause an increase in the generated high frequency noise; but if checking the grounds doesn't help; you should probably take it to a shop.

Also - what is the age of your GPS?? Is this new? It is unlikely; but also possible - that the shielding in the GPS is faulty. (They do have shielding.) So, if this is a new unit; you might look at possibly trying a replacement.

I only wonder about this - since the GPS is experiencing interference even when not connected to the vehicles powers source. Usually with a bad ground or something; this causes noise in the 12V line; which then interferes with a device.

However, your device is experiencing interference just from proximity to your vehicle. And, finally, although the device does have some shielded components; the FCC requires that all of these types of devices 'accept' harmful interference.

From your use of the term 'earth' - I suspect your not residing in the States; but still the basic design of the unit probably conforms to the FCC requirement. However, even with all of that - it is either a defective GPS; or some defect in your vehicle. And if the GPS has defective shielding - your vehicle could easily interfere with it - especially if your vehicle has some difficulties - since cars generate a TON of high frequency noise.

Hope this helps.

D.
 
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Do you know where the van has been used before you got it, perhaps a large company who fitted GPS tracking kit followed by a driver who fitted a jammer so his boss couldn't see where it was - It might sound like Sci-Fi but it does happen, do you know and trust the history of the vehicle - Mike
 
tom tom wont work when i switch ignition of car on?

:confused::confused:have checked all earth points straps etc,not Radio Frequency Resistor,the vehicle is not new 04 plate,renault clio car van sl15 dci 65 1400cc diesel,so no spark pulgs,the tom tom is working perfect outside inside vehicle until ignition is switched on?? yes it did belong to a company highway surfacing ltd so i dont know about tracking device but something is infereing with signal when ignition is switched on?? real puzzle ??
 
Sounds like Mike is on to something.

Take it to a friends car, or a neighbors car for a moment. See if it works in their car. Probably will.

You need to find out what is interfering with the GPS in your car. Since it was previously owned by a Highway Company - as Mike suggested - probably some sort of jammer or some specific electronic device. Either to a specialist on Foreign cars we go; or to a security expert with signal tracking devices - or possibly sell this vehicle, and purchase a different vehicle.

Or contact and talk with the company that previously owned the vehicle; and see if they might have any suggestions.

D.
 
tom tom wont work when i switch ignition of car on?

yes i think mike is onto something too....works in mates car,tried contacting company but no answer or ringing at all....sounds like tracking device or eletronic device?can anyone recommend anyone for this type of work :confused:
 
I wouldn't be too surprised if a Highways Agency vehicle was fitted with a GPS tracker which reported the position of the vehicle to the office on a regular basis. The tracker will have been removed prior to sale of the vehicle because they are far from cheap, even if it were left in the van it wouldn't cause interference to other GPS equipment to the extent you are experiancing.

Now for the Jammer, totally hypothetical (but not uncommon even if its illegal to do this in the UK). HA employee knows the vehicle has a tracker fitted so he purchases and fits a GPS Jammer so his office can't see where he or the vehicle actually is. Employee is dismissed and vehicle is sold on with the jammer still fitted.

All a bit Sci-Fi stuff but possible in this day and age!

To be honest I would put the GPS in the van, pull every fuse (making a note of which ones came from each slot).

Turn the GPS on and let it acquire a position fix.

Turn the Ignition on.

Now replace the fuses one by one, leave a period of ten seconds or so between each fuse replacement for you to check the GPS reception on the nav unit.

Once you have identified which circuit in the car is responsible for the interference locating the cause will be far easier.

Out of interest where in the UK are you located? - Mike
 
I was going to suggest something similar.

If you are handy and understand electrical; or if you have a friend who knows some electrical stuff...

First - get yourself a Vehicle Maintenance Manual. Either from the dealer or a cheaper one (with schematics) from a Parts Store.

Then, start your vehicle; and then (sort of like Mike suggested) unplug and remove a fuse. Wait a bit; and see if that brings your GPS back. Working a fuse at a time.

Try the Radio, circuit first. Stop light & taillight circuits are always active (so it is not going to be those two circuits). Plus, lots of times - people tap into the Radio circuit.

You can also first see if the GPS fails on 'accessories'. The radio circuit would work on 'accessories' (key turned to that position); and they might have also wired it into the 12v power outlet circuit (cig lighter).

ALSO - just poke around under the dash - with a flashlight; and see what you can see. And look under the seat, and under the hood. A jammer is going to be visible; and probably identifiable when seen as (Gee, I think that's it... Looks like an add on; with definite non factory wiring tied into the factory wiring harness...)

D.
 
Andy "So with the TomTom working on battery power, if you turn on the ignition, the signal dies?" YES.....:( thats exactly what happens

Wow! I really don't know what to suggest then.
You can get various interference suppressors for the car radio, but they are just for cable-bourne interference (like your original idea of an earthing problem).
But if this is being sent "over the air", your car is probably acting as an illegal transmitter! :eek:
 
thanks for comments all who posted,

mike, me and my mate have done what you said today for 4hrs (actually had done that and returned to read what you said do lol)...took fuses out one by one but saying that we didnt take all out so might be worth doing that take photo of fuse box.... then take all out and replace one by one thanks for that....this has been so challenging today .....ps, also tried an external plug in gps magnetic(sticks on roof)antena as well still loses signal ??:confused:

like i said only happens when turn key ignition on?:rolleyes:
 
I would try pulling all the fuses and make sure the device has got a signal BEFORE switching the IGN on, then replace fuses one at time as described earlier.

Where are you in the UK?? - Mike
 

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