Audio Systems: Car DVD player causing AM not to work, fm modulator, connection topology

Question
I have Toyota Sienna 04, when I bought it the dealer used a third party to put dvd player. Recently I found out that none of the AM stations are coming ..I never used to listen AM station before but now my 4 yr old daughter want to hear disney AM 600. The dealer told me some AM/FM modulator is defective and not working the way it supposed to work and it is causing it.Now since my van is more then 4 yr old it is not covered under warranty. I do have extended warranty on my van for 5 yrs. And I asked him if it is defective and I happen to notice it after 4 yrs, this is something he should replace it under extended warranty. But he is not considering it. what should I do? Any advice?

Answer
Without knowing the system (equipment installed, make and model and connection topology) I can only give you some generic comments.

Probably an after market third party system would not fall under the car warranty or extended warranty. Most 3rd party aftermarket stuff is only a 30 or 90 day warranty.

There should not be a modulator in this vehicle; but a receiver or "demodulator" maybe.  But, if it is defective it can be replaced.

A car dealer is about the last place to get information on this kind of problem - unless they happen to have a radio expert on staff - which not very many do.

You should go to an installer/repair place - and one that handles the brand of equipment installed in the Sienna - for a diagnosis.  I doubt if this is a very expensive repair. Probably under $100 at a place that works on thise kinds of problems.

Good Luck,
C