Buzzing when towing a trailer

[mrjimbo]

Where is the flasher unit located, and which 4 pin flasher unit does it need to be replaced with ? will any 4 pin flasher unit be ok ?

I need to do mine before i start using my trailer again so i'll need to get a flasher unit ready.

[mrjimbo]

I can confirm that fitting the bulb in the dash and fitting a 4 pin flasher relay does indeed activate the warning light on the dash panel        

It's an easy fix/mod and took me just 20mins from start to finish. I used a 4 pin flasher relay from Hella part number 4DM 003 360-001 which cost £12.27 inc VAT. Durite also do one part number 0-744-62, and the part number for the bulb from Vauxhall is 91155676 and cost £0.81 +VAT.
The flasher relay is located in the fuse panel under the steering column, just turn the flashers on and feel the relays, the one that can be felt clicking is the one you need to remove and replace and there is a guide to removing the instrument/dash panel in the mantainance section.                                                                                                                                          
                                                             

[Kevin Wood]

Excellent. Thanks for providing all the details.  

Kevin

[mrjimbo]

No problem  

It's a cheap and easy fix anybody can do without paying dealer prices, also helps keep you legal when towing  

[Kevin Wood]

May get round to it myself so I can ditch the irritating buzzer.

Kevin

[davlad22]

Is this an ACTUAL indication of whether the trailer indicators are working or just a feed to an extra flashing bulb?  :-/

Kev, or one of the other lads, would any of you be able to draw out a quick wiring diagram? I'm not entirely convinced! A link to some trailer wiring would also be helpful  

[andyiow]

If the indicator bulb has blown the the buzzer does not work. Only know this as a bulb has just gone on my nieghbours borrowed trailer. (ex caravan so carries a fair weight ie 1ton bag of ballast fits a treat)

The buzzer is handy for the indicator checks I do every time the trailers connected.

Trailer wiring http://www.tridenttrailers.com/trailer-wiring-diagram.htm

[Andy B]

......
The buzzer is handy for the indicator checks I do every time the trailers connected. ....

In Shyboy's case a lamp is a lot handier to see if you're mutton Jeff!  

[Kevin Wood]

The buzzers work by sensing current in the wire to the trailer indicators, so they are an indication that the trailer is drawing current and that, presumably, the bulb is working.

I believe the extra pin on the 4 pin flasher units is only activated when the indicator circuits are drawing a greater current than the normal vehicle indicators so they also give an indication that the trailer lights are working.

Kevin

[Andy B]

......
I believe the extra pin on the 4 pin flasher units is only activated when the indicator circuits are drawing a greater current than the normal vehicle indicators so they also give an indication that the trailer lights are working.

Kevin

Sounds about right. The trailer tell tale will also light when you have the hazards on too.

[Kevin Wood]

......
I believe the extra pin on the 4 pin flasher units is only activated when the indicator circuits are drawing a greater current than the normal vehicle indicators so they also give an indication that the trailer lights are working.

Kevin

Sounds about right. The trailer tell tale will also light when you have the hazards on too.

That confirms it then. Flasher unit is running double the normal wattage of lights with hazards on.

Kevin

[mrjimbo]

Yeah, the dash warning only comes on when the trailer indicater is actually working, if the trailer indicater bulb is blown then the dash warning light doesn't flash.
Just tried it with my trailer  

[shyboy]

Just caught up on this. Thanks for the details, Mr Jimbo.  I'm going to do it when I get a minute.

[davlad22]

So, the extra bulb will do the business irrespective of how the trailer wiring has been connected?

[Kevin Wood]

So, the extra bulb will do the business irrespective of how the trailer wiring has been connected?

Should do, as long as the current to the trailer bulbs goes through the flasher and isn't switched by a relay at the rear end, for example.

Kevin