# Why have I lost the AM signal on my car radio? **URL:** \ **Category:** Factual Questions\ **Created:** [June 20, 2014, 2:09pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204 "2014-06-20T14:09:27Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![DummyGladHands](https://avatars.discourse-cdn.com/v4/letter/d/49beb7/32.png) [@DummyGladHands](https://boards.straightdope.com/u/DummyGladHands)\ **Post date:** [June 20, 2014, 2:09pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/1 "2014-06-20T14:09:27Z")
Just the factory installed radio, but AM was just fine until about 2 weeks ago, now it’s mostly fuzz all up and down the dial. Some days I can pick up a little but have to turn the radio way up and it’s still not clear. Nothing new added to car. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [June 20, 2014, 2:15pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/2 "2014-06-20T14:15:28Z")
Does your car have an antenna? Perhaps the cable from the radio to the antenna became disconnected. How old is the car/radio? ---
**Author:** ![DummyGladHands](https://avatars.discourse-cdn.com/v4/letter/d/49beb7/32.png) [@DummyGladHands](https://boards.straightdope.com/u/DummyGladHands)\ **Post date:** [June 20, 2014, 2:38pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/3 "2014-06-20T14:38:54Z")
'07 and I would have no idea where the antenna is, but you’ve made me think-could it be something to do with the rear window which I recently had re-tinted? The installer told me he had to do something or another with the rear window defroster. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 20, 2014, 2:48pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/4 "2014-06-20T14:48:01Z")
You could start by just crawling under the dash with a flashlight or reaching behind the radio (it’s really going to be a major PITA) to make sure no wires came out of the head unit. The radio may not even be accessible from that direction, but it’s easier the pulling it out, especially since it’s probably not even the case. Next, I’d google [make model year of car] + AM radio antennae to see if I could find out where it was located and then check that end. ETA, I didn’t see that you had the rear window tinted. Yes, check to make sure there’s no wires dangling back there. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [June 20, 2014, 3:27pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/5 "2014-06-20T15:27:24Z")
I know that they have antennas built into the windshields of cars, but I didn’t know they sometimes used rear windows. If you can get to the back of the radio you should see some wires going to the speakers, some power wires, usually black and red, and usually a thick black cable going to wherever the antenna is. My money is on either that antenna wire is not connected to the antenna, or the radio may have an internal problem… ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [June 20, 2014, 3:30pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/6 "2014-06-20T15:30:39Z")
There’s also a possibility that a ground between the radio and the car chassis has come loose or broken. For some reason AM seems to be affected by that more than FM. But the first thing to check is the antenna. ---
**Author:** ![Kimballkid](https://avatars.discourse-cdn.com/v4/letter/k/b5a626/32.png) [@Kimballkid](https://boards.straightdope.com/u/Kimballkid)\ **Post date:** [June 20, 2014, 3:35pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/7 "2014-06-20T15:35:04Z")
What kind of car? ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [June 20, 2014, 3:40pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/8 "2014-06-20T15:40:05Z")
Dim memories of electronics school tell me that the AM and FM parts of radios often have separate antennas because of the greatly-different frequencies they use. Not sure whether that applies to a car radio though. ---
**Author:** ![obbn](https://avatars.discourse-cdn.com/v4/letter/o/d6d6ee/32.png) [@obbn](https://boards.straightdope.com/u/obbn)\ **Post date:** [June 20, 2014, 3:46pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/9 "2014-06-20T15:46:42Z")
Did the issue start when the rear window was tinted? If so, that’s your probable cause. I’m not sure about your car, but it is possible for the antenna to be integrated into the rear window. Most likely if it is related to the tint would be a loose or cut wire. It is also possible, but unlikely that the tint itself is interfering with the antenna embedded in the window. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [June 20, 2014, 4:12pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/10 "2014-06-20T16:12:35Z")
Searching on “tinted windows radio reception” brings up a lot of hits… ---
**Author:** ![DummyGladHands](https://avatars.discourse-cdn.com/v4/letter/d/49beb7/32.png) [@DummyGladHands](https://boards.straightdope.com/u/DummyGladHands)\ **Post date:** [June 20, 2014, 6:08pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/11 "2014-06-20T18:08:56Z")
ZenBeam et. al. thanks, just got off the phone with them after googling as ZenBeam said. Metallic film. ---
**Author:** ![BrotherCadfael](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)\ **Post date:** [June 20, 2014, 7:02pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/12 "2014-06-20T19:02:59Z")
Every couple of weeks, I get in the car, and the AM is gone. I drive to work, leave the car in the parking lot for eight hours, and when I get in to go home, the AM is back. No idea why. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [June 20, 2014, 9:51pm UTC](https://boards.straightdope.com/t/why-have-i-lost-the-am-signal-on-my-car-radio/691204/13 "2014-06-20T21:51:19Z")
putting metal next to antenna will affect its performance. it could improve in some very select situations but by far most of the time, almost all of the time, it makes it worse.