Hi all , its been a long while since I have posted any thing on this forum , but never needed any further advice until now.

 

I still got a fabai vrs manual 2004 .

 

the car has done now 138000 miles.

 

i got a issue which has just started tonight.

 

when to work in car , radio on etc no issues .

 

got in car tonight and started driving home with radio on but now when i apply the foot brake i loose radio reception and get a bad interferance crackle sound only when i depress the brake pedal .

 

i got home checked the brake lights and condition of the bulb holders and bulbs , all ok and no corrosion. despite this i change the brake light bulbs for a pair of new ones .

 

took the car back out on the road , still the same issue.

 

as far as i can tell it does not loose radio reception when the car is not moving when i apply the brake pedal .

 

also i believe it only happens when i press the brake pedal more than just lightly .

 

I have read it could be a issue with the arial amplifier or brake pedal switch ?  Or a faulty resistor inside the radio or a bad earth point on the car ? But where ??   

 

can any one who has had the same issue advise on the fix for this please ?

 

thanks all .

 

regards 

What headunit do you have?

Tighten radio reception!!

morning, its got the standard factory fitted syphony radio abd cd player.

 

radio only cuts out when the car is on the move and not when its stationary it seems.

 

How would you tighten radio signal ?   change radio amplifier  in roof ??

Sounds like the aerial plug is loose in its socket to me.  See if reception still drops out if you use engine braking to (abruptly) slow the car rather than the brakes.

Edited 5 August, 20169 yr by Wino

only does it with brake pedal braking and not if you just gradualy press the pedal slightly, after about half way approx on pedal ish 

Sounds like the aerial plug is loose in its socket to me.  See if reception still drops out if you use engine braking to (abruptly) slow the car rather than the brakes.

That's what I meant, with the note that the aerial signal lead could be loose at either end.

can i get in at the cable from round the back of the console or is it head unit out etc ?

 

i would of thought if the cable coax was loose it would be a bad signal all the time ??

Possibly bad earth somewhere. Check rear lights operate OK - not just brake lights

I had this in a land rover with 2 way radio (!) there was a failed shorted brake bulb that drew excessive current causing interference when brake pedal was pressed. Check your brake lights work properly.

Edited 5 August, 20169 yr by poiuytre111

hi, have put in 2 new brake light bulbs . made no difference .

 

i check the earths in the boot tonight , might need a clean up ? but doubt it this is the issue .

 

looking at roof mast aerial it looks like it has seen better day as the base of the mast the rubber has started to perish so base mounting plate may be shot which might cause the fault ?  i still think it could be a bad brake light switch causing it but carnt understand how this would cause the problem as its a another unlinked circuit ?

I don't think that rubber round the base is the actual weather seal, it's just cosmetic. Mine is missing completely on my Polo, and there's no water ingress, judging by an unmarked headlining.

 

And I don't think you'll access the back of the radio without removing it from the dash.

A poor contact could arc and create radio-born interference so doesnt need to be on same circuit.

hi, have put in 2 new brake light bulbs . made no difference .

 

i check the earths in the boot tonight , might need a clean up ? but doubt it this is the issue .

 

looking at roof mast aerial it looks like it has seen better day as the base of the mast the rubber has started to perish so base mounting plate may be shot which might cause the fault ?  i still think it could be a bad brake light switch causing it but carnt understand how this would cause the problem as its a another unlinked circuit ?

^ Yeah, good call. And frankly, if the brake light switch has never been changed, it will be arcing and about to die at that age/mileage, I'd imagine.

 

This:

 

"as far as i can tell it does not loose radio reception when the car is not moving when i apply the brake pedal"

 

is hard to integrate into that theory though, I think?

 

 

This:

 

"also i believe it only happens when i press the brake pedal more than just lightly"

 

is what makes me think it's physical acceleration/deceleration that's moving something with a poor contact in the aerial signal path. And why I suggested the engine braking test to see whether it was braking or just decelerating that does it.

Edited 5 August, 20169 yr by Wino

Welll got home. Cleaned up earth bolt and nut and two earth wires in boot and refitted. Took car for a drive. Problem still there.

So since had a new aerial assembly i dropped headling and removed trim etc and fitted new aeral assemby. Bit fiddly and tight getting a spanner in. But manated. Heqdling creased a little but hopefully will straighten up and creases will go?

Any way then i took car for drive. Problem still there.

Every time when i press on the brake pedal with meduim pressure not light pressure with the car radio on when and only when the car is moving i loose the signal on the radio until i take my foot off the brake pedql. The problem does not occur if i am staionary. Only when i am on the move in the car. Suspect now brake pedalvswitch? Unless any one can suggest otherwise? Thanks for input so far

Try stopping the car (from low speed, not near traffic) with the handbrake instead of the footbrake. If the problem still occurs it isn't the brake light switch ('cos that's on the pedal).

Unfortunately, because the deceleration will be much more gradual than with footbrake, if the problem doesn't still happen, it wouldn't necessarily be fair to conclude that it is the brake light switch.

Edited 5 August, 20169 yr by Wino

I try that tomorrow. I wonder if i disconnect the brake light switch wiring from the switch next week at some point and try that on my local street or will it cause the car to go in to panic mode. Would the obd tell if i get it tested out the fault? Or is it a job for a garage or auto electrian if i get a new switch next week and that doest solve it? Must be something simple to fix it. Age and milage may be all factors perhaps and it could be a fault inside the radio? Doubt it mind.

Well tried the engine brake test and the handbrake slow down test fault doesnt happen. . So thinking outside the issue going back to old school and car speakers of old cars

I am going to have a look at the speakers i think in the doors to see if they are all working by tuning the radio in just to see if the reception is lost in the car from the back or the front speakers just out of interest as might be a sound system fault not a brake as the switch still works and it wont involve taking stuff apart yet. I have a look tomorrow

Edited 6 August, 20169 yr by kt600