Hi guys

Just had a problem occur with my navigation last week. I last drove the car on a Friday and didn't drive it till Tuesday and nothing was wrong on Friday.

The entire screen is black, the climate, info, defog, everything on the top part of the navigation doesn't work, no lights turn on as well.

I checked the fuses and everything works except for one 7.5 on the driver side

The only thing I installed was LED signals that I bought from a seller on here, but the seller did a poor job with the sealing which resulted in water leaking into both signals.

Besides the fuses, I can only thing of the relay having issues, unless there is a loose wire that connects the navigation.

Anyone have any ideas what might be the problem?

Thanks!

I have a 2006, and a few weeks ago my navigation went out as well. The climate, audio, info, and display all appear on the screen when pushing the buttons. When in reverse, the back up camera displays on the screen as well. However, when I push either of the three navigation-related buttons I get a message appear at the top of the screen that says "External system not connected". As it turns out, the nav ECU crapped out. A new one will be about $1500, so it's a good thing I rarely used the navigation anyway. It just sucks that I have to look at a black screen.

As for your problem, a little more detail would be great to help give suggestions on probable causes. You said one fuse wasn't working. Did you replace it? And have you checked to see if any wires were broken or loose? That's where I would start first. If that doesn't fix it, try to post more details on what works and doesn't work.

I replaced the fuse and still no power goes to it, I used a test light to find out if there is power or not.

I didn't take the navi out yet but I did order a new defog relay for cheap to see if that was the case since no power is going to the middle 7.5 fuse on the driver side

Could the water leakage in the signals caused this problem?

Have you looked in the manual to see what that 7.5 fuse powers?

And water can definitely wreak havoc on electrical wiring. It's just hard to say if that's what is causing your problem without knowing what wiring the water has come in contact with.

Ouch $1,500 to repair the Nav. I think I might get the 8year Lexus Extended Warranty on our 2012 IS-250-loaded ,with Nav as well.

I'm hoping it might be the relay or a loose wire, strange thing is that the clock and emergency light still work and the emergency light button still lights up when I turn my lights on at night but the rest of the navi is dead

Just took the navigation out and all the harnesses are plugged in. Fuses are fine as well,

Anyone have any ideas? Is there a way to reset the navigation system?

Bump anyone have any ideas ?

I have this exact problem. Any answers?

My battery was low but the car would still start. After a week or so, the battery died so I got a new one and everything works fine now

That's funny. I actually need to replace my battery. Thanks for your input.

Okay, I'm in this same boat as well. Tried to troubleshoot the XM on the IS-F and the external system is not connected message for the NAV. Could this be a security feature?

all i can tell you double check all the fuse.remember to put it back the right place where it belong.it happend to me before.i know the fuse 7.5 amp on driver side for the a/c.you don't have to read the manual because it doesn't look exactly as the plastic cover of the fuse in your car.when you see fuse you don't know then start read manual to see what it related to.i make mistake when i took fuse out to check and put back wrong place and that why it didnt work.it took me like coupe days to find out.dont bring to dealer because i did and they told me they gonna charge me 650$ for 5 hours tear out the dash.i said no way.you gotta be patient.i did waste my time tear out the dash and took the navigation out and left coupe mark on my dash.like i say make sure all the fuse not flew and put back right place where it belong before tear out the dash.good luck and sorry for my English.i just wanna help.

If your battery is low, your navigation and some other electric won't work due to safety feature from lexus.

AZ06IS350, have you try reset ECU yet? Disconnect negative terminal for about 1 minutes and plug it back on. It fixed vary problem on our car.

I replaced my battery with a red top optima and it still hasn't fixed the issue.