External antenna and losing signal

Check to be sure that the external antenna for that model is not for the traffic service ONLY.

If that is the case, you will still have to have the Nuvi up near the windshield.

what brand antenna do you use? You may want to give the maker a call and ask.

Also, what do you mean by "driving on high"?

One of the things I would do is to drive around with the GPS displaying the satelite screen and observe whats happening. I've never had to use an external antenna with my Nuvi 750 but I have an external antenna and if I hook it up there's a huge difference is signal strength. With the antenna, the vast majority of the satellites received always have a max signal strength and there's always lots of them (6-10 on average).

One possibility is that you happened to hit it on a bad day when there were only a few satellites orbiting in your view and they were in a bad position for the GPS to hold a fix. It can get very bad if there are only 2 to 4 and they are in a straight line pattern (poor to no triangulation). Your satellite screen will also show you how many birds are around and where they are located in the sky.

Also, check your antenna... watch the satellite screen and insure that the antenna is actually improving reception. The difference should be really dramatic.

Good Luck.

Before you got the external antenna or before this outting? You may have been between buildings or some other object blocking the sats... If the problem started after you started using the external antenna it could be defective or a poor connection to your receiver... I have never found the need for an external antenna since I got my nuvis

I will double check it tomorrow and report back the outcome. I meant highway when I said high in my previous post. There are no high buildings around highway 401 but it was very cloudy.

But moundains could... I notice you are in Canada..

I tried external antenna agian today. Looks like it is defective. It worked today but few times I noticed signal going down. I bought it from Ebay and it is cheap $8 antenna. I don't need it everyday. It is only to be used when going to downtown Toronto where you lose signal when you are surrounded by tall buildings.