No FM reception with car running
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=21515
Printed Date: September 15, 2025 at 10:43 PM
Topic: No FM reception with car running
Posted By: Christene
Subject: No FM reception with car running
Date Posted: November 15, 2003 at 4:57 PM
Hi guys, I'm hoping someone could help me witht this. I just installed a factory stereo into my car. The stereo works great and I get great reception for am and fm when the car is not running. However, as soon as I turn the engine on, I have no more FM reception but manage to pick up a few stations that are definitley not local. Furthermore, with the engine running the AM stations work fine. Also the radio will pick up clicking noises from my signal lights in FM. Finally if I turn the car off, then click the interior lights on and off a few times with the engine not running the FM reception will come back crystal clear. Is this a problem with my ground? I know the antenna is plugged in and stuff too. Any suggestions/Help please.
Replies:
Posted By: Velocity Motors
Date Posted: November 15, 2003 at 5:03 PM
What year, amke & modl is the car ? Sounds like you may have grounded the system to your dimmer wire ?
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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: Christene
Date Posted: November 15, 2003 at 5:09 PM
the car is a 1995 hyundai accent. I have all the wiring schematics. I know I connected the ground wires correctly. However, it is possible that I put the + dimmer wire where the - dimmer wire should go and vice versa. If this is the case, is it possible for the dimmer to still work, but not have fm reception.
Posted By: Velocity Motors
Date Posted: November 15, 2003 at 5:17 PM
Did you use a wiring harness or just hard wired the system in ? The FM reception should not be affected by the wiring at all other than if the power antenna wire was not hooked up ( if applicable ) . It sounds wierd that the reception would be affected by the wiring. I would check the power, ground and illumination wires first to see if they are correct , WITH A DMM not just comparing a chart to the car.
-------------
Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: Christene
Date Posted: November 15, 2003 at 5:22 PM
No wiring harness used, all were just hardwired in with using a dmm. I will check wiring again. darn, this means I have to rip the dash apart again.
Posted By: forbidden
Date Posted: November 15, 2003 at 5:52 PM
While you have the dash apart, if you have a cordless drill that has a 12-14.4 volt battery, use it as a power / ground source. This takes the vehicle wiring out of the picture. If you do not have a battery like this around, run some temporary power and ground lines directly to the factory battery and check your reception problem again, it does sound like you have something on the circuit interfering with your reception, this can be verified by either of the two methods above. Have you replaced or rewired the factory antenna recently? ------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: Christene
Date Posted: November 20, 2003 at 3:57 PM
Took the dash apart, redid the wiring with a DMM, double checked everything and it is still the same. I even regrounded it but I still don't get reception in FM. I have no idea what to do now.
Posted By: forbidden
Date Posted: November 20, 2003 at 4:24 PM
Run the new wires directly to the battery for power / ignition / ground. This removes any extraneous circuits from the supply path. Test again. What make / model cd player did you install and did yu buy it new or second hand / pawn shop etc. If you can get another antenna from a store (just a cheapie that you can return) you can also plug in the new antenna and retest for reception again. It still sounds like something in either the power / igniton / ground circuitry or a radiated noise in the vehicle electrical system that is interfering with reception. Keep trying. ------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: Christene
Date Posted: November 20, 2003 at 5:35 PM
The stereo was bought second hand from a dealer and I saw it working, mind you it was only working straight off the battery with no engine running I ran seperate ground and hot wires straight to the battery. I disconnected all the speaker wires. Here's what's really weird. I'd hook up the corresponding wires for the rear psgr speaker and with the accessory on I'd get no reception, until I took the + fd and -rd coming from the HU and pressed them together, then the reception would kick in. But once I turn on the engine it all goes to hell and I get no reception. I don't know what the F is going on
Posted By: forbidden
Date Posted: November 20, 2003 at 5:58 PM
Keep at it, try this, disconnect all of your speaker wires again. Find yourself a speaker, any speaker - home speaker - used car speaker whatever, just not one of the speakers in the car. Hook this new speaker up to the cd player again with the power / ignition / ground still hooked direct to the battery, retest. It really sounds like a vehicle wiring issue, just because the dmm says you have impedance showing does not necessarily mean it is a speaker. Have a look at this website for some info on your car to compare it with what you had to begin with. www.installdr.com find your make, model, year and open the pdf file for your car (if it's there) it may have the vehicle wiring color codes there. This will allow you to double check wiring. Post up the make / model of your cd player. ------------- Top Secret, I can tell you but then my wife will kill me.
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