• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Radio signal dies only when LED Headlights are on. Weird :0 -Solved

Z66Modder

Regional Coord.
SM 2024
SM 2023
SM 2022
SM 2021
SM 2020
SM 2019
SM 2018
SM 2017
SM 2016
SM 2012
SM 2011
Full Member
Joined
Oct 23, 2006
Messages
4,812
Location
University Place, WA
So I modded my shark fin antenna mod and put in a amplified BMW /VW 9" antenna. The shark fin just doesn't cut it in hilly areas.  (n)

index.php


31prUUZkLIL.jpg


So this antenna has a PC board with transistors and diodes so it's the real deal for a preamp but required 12 volt input on the center conductor. European radios have this feature built in but not my after market DVD player. So i had to get an adapter.

31DBpHE2lTL.jpg



So after changing every connector to meet my system I got it working and working well. That was until I went for a test drive at night.

Like WTH? it just quit. So I'm sitting on the side of the road with all the wires hanging from the overhead like spaghetti and everything checks out. So since I'll be there a while I killed the headlights and BAM  the signal comes back. So put the LED lights back on, no signal. Go to parking lights, signal is back, go to bright lights signal is still good. It only dies if the LED headlights are on.

So is it an EMI noise from the fans or the Cree lights themselves? Can it be corrected?

$_57.JPG
 

Attachments

  • Antenna Card.jpg
    Antenna Card.jpg
    81.8 KB · Views: 125
is the 12v there when you turn the headlights on?
 
My bet, like your suspicion, is that it is RFI from the LED headlights. I have a pretty old HID low beam set in the Avalanche and the radio range is considerably reduced when the HIDs are on. Turn them off and the signal comes back. I haven't worried about trying to do anything about it, but if I was going to I would buy a new Canbus HID set. I'm sure you could eliminate the RFI but it might cost more than it's worth. Maybe you should swap the LEDs out for a good Canbus HID set? That's probably not what you want to hear so you have to decide whether the LEDs or radio reception at night is more important.
 
ItsStopher said:
is the 12v there when you turn the headlights on?

I was thinking about that last night because I could not remember where the source is for that wire. I'm sure it's tied into the amp control circuit but will double check today.

I replaced the HID's because I did not like the time delay for them to come on, so worst case scenario, no radio at night. 
 
What brand LED light are you using? Could be an issue if you bought cheap ebay LED's.

They cut corners some how...  Otherwise haven't heard of issues with others with LED's.

You can also check that your grounds are good. A bad ground can cause excessive RFI as well. Ground on your antennae and the lights. If you are just using the factory wiring you might consider trying the LED's with a separate wire harness that connects directly to the battery.

Rodney
 
Thanks Rodney.  (y)

They were a gift from my son and those in the picture are Ebay ones I'm sure. The antenna is grounded at the base and at the input to the radio. I can see if extra grounding at the lights will help. It should as that is what we do for customers if the high frequency for TIG welders starts interfering with phone circuits and such. I tried just wrapping the switching power supply boxes today in aluminum foil but it had no effect.

In doing some research, there are a lot of people complaining about RFI form LEDs and not just automotive. Some of the household bulbs bought at Home Depot are causing Ham operators to loose certain bands. The soft whites seem to be worse then the standard ones.
 
Couple of questions.
How bright are they compared to HIDs?
Is the beam focused so that you can see driving with them at night or is it diffused light?
Do you guys know if they will work with projectors or not?

I am about tired whit my HIDs at this point. The bulbs are fine but the ballasts just don't last.
Then there is the issue of the auto headlights on the avalanche where anytime after dusk when I start my truck one HID flickers and shuts off and I have to push the button to go to manual mode and back for them to come on.
I even modified the HID circuit so that it draws power from the battery and it is still an issue when the truck is cranking.
Heck I haven't listened to FM or AM radio in my truck in seven years since the AvalanchePC first got installed.
I am worried that it may affect some things in the truck but the radio is not one of them
 
For headlights look at VLED's. They are more expensive but I have talked to people using them and they love them.

I am about to pick up some JW Speaker LED headlights but the sticker shock will likely make this a "me only" option.

I suspect that the issues are related to the fact the LED's are likely not constantly on and are turned on and off quickly to try cooling them.

I would check in to more expensive LED's such as the VLED's (But would contact  them first to insure they don't "flicker them" for heat management.)

But look into the potential grounding issue first.
 
Couple of questions.
How bright are they compared to HIDs?
Is the beam focused so that you can see driving with them at night or is it diffused light?
Do you guys know if they will work with projectors or not?

I am about tired whit my HIDs at this point. The bulbs are fine but the ballasts just don't last.
Then there is the issue of the auto headlights on the avalanche where anytime after dusk when I start my truck one HID flickers and shuts off and I have to push the button to go to manual mode and back for them to come on.

I love the LEDs I have in now except the noise generation. Instant on, consistent bright white light, better light generation than HID's probably because the bulb element is close to the same size as factory. I'm also not found of the blue tint of 7K and above lamps. Mine are 6K and the whitest lamp I've ever used. Might have to invest in the higher grade ones to get this RFI problem solved.

As far as grounding goes, I'll try some case grounding first. Then if needed I will have to incorporate relays with coil control from the factory harness and individual fused supplies  from the battery and direct grounds. That's about as far as I'll probably take it.



 
I've been looking at these namely because all the wiring is incased and will not easily be affected by the weather. I also like the design as the fan is in the back and will do the cooling as necessary. At $179.00 it is more price friendly than the VLEDs. I'm wondering if I should get 9007s for both high and lo beams or get H4s with a projector upgrade for my my truck.

http://www.gtrlighting.com/led-headlight-9006-conversion-kit-2-200-lumen-bulbs/
http://www.gtrlighting.com/led-headlight-9007-conversion-kit-2-200-2-600-lumen-bulbs/
http://www.gtrlighting.com/led-headlight-h4-conversion-kit-2-200-2-600-lumen-bulbs/
 
I like how those have metal vented covers on the fans. I could make some for mine if it helps with the noise. Will look for some braided stainless steel mesh to slip over the cables too.

SSNtopimage3.jpg
 
So I pulled the LEDs out and put back my HIDs while I mod the LEDS. Just to be sure, turning on the headlights did not change the reception.
So I bought a 3' vacuum hose that  had stainless steel mesh already on it vs. buying the full blown kit for $50 which had way more things then I needed.

So first shot is a close up of the triple bulb.

Second shot is the inverter powers supply.

The third shows shielding cable between the lamps and the PS with grounding lead attached.

This will take some time, not much money, just a lot of time.  :p

 

Attachments

  • LED 1.jpg
    LED 1.jpg
    82.6 KB · Views: 94
  • LED 2.jpg
    LED 2.jpg
    81.3 KB · Views: 94
  • LED 3.jpg
    LED 3.jpg
    77.6 KB · Views: 92
You may want to ground the mesh.
 
MS03 2500 said:
You may want to ground the mesh.

Yes sir, that's just the beginning. I'm running grounded shielded cable from the battery to the relay and lamps as well. I only need to tie into one of the factory lamp sockets for signal control. Will use an old HID harness connector to keep it water tight, plug and tape the other and seal with liquid electrical tape.

The picture shows the heavy duty 12v relay that I added liquid tape to weather proof, fuse holder is also weather proof.

Now to get some screen material for the fans.
 

Attachments

  • Relay-and-wires.jpg
    Relay-and-wires.jpg
    96.2 KB · Views: 91
Hi
I meant to ask. Are those LEDs dual mode high and low beams?
I noticed one of the previous pics showed 2 modes. I would like to have both high and low in one bulb than to have to buy 2 sets.
 
No they all come on at once. The seller had different styles depending on the bulb type. 9006 was triple while 9007 was single. Its actually 4 LEDs on one pc board with 1 large lens.
 
If I ground at both ends will that create eddy currents?
 
Z66Modder said:
If I ground at both ends will that create eddy currents?

You can create ground loops if grounding at both ends of a shield.  The shield will then become its own loop antenna.

We had a 60hz hum coming through one of the mics at church.  I discovered someone had grounded both ends of the coax shield on the cable running from the mic to the amp.  I removed one of the grounds - hum gone.
 
Did a lot of research last night and depends on what type of EMI noise. If E field inductance is the root , ground only one side for low frequencies but both end for higher frequencies or even multiple points for very high frequencies. All depends on the wave length.
 
I've been thinking of doing an HID retrofit with the LED bulbs but have to wonder if they will work well together. I know you can't get good light output by putting HID bulbs in Bi-Xenon projectors or xenon bulbs in HID projectors so I have to wonder if same is true for LEDs.
Any thoughts?
 
Light dispersion is much better with LEDs due to the source being almost the same size as an halogen.,The HIDs are such a long bulb, light emits everywhere.
 
MyBigToy said:
Any progress?

Its on hold until the rain stops. Might do some work on it in the garage Saturday.
 
Ordering a set of LED bulbs today. I think I still want to cutoff the HID projectors provide so I may end up adding that too when it gets warmer this summer.
Another one of my HID ballasts (one of the fog lights) blew again last month. This one only lasted a month unfortunately.
I am also dealing with the auto headlight feature as well as the HIDs ballast can't handle the current draw when cranking. My HIDs flicker and one bulb always shuts off when the truck is started after dusk or before dawn. I then have to override the autolamp feature then re-enable it for the light to come on. I even rewired the HIDs to get power directly from the battery with a relay connected the the original light harness and that did not work either. So I've convince my better half I need LEDs.
 
Back
Top