Yes, the relays with a mounting tab can be handy, like the one in my
photo has. Your description of your use of pins 85 and 86 is not what I
did at all for the horn usage though. I guess I will post more details
about the relay wiring at a later time. Because it is a horn circuit we
are actually using the relay for controlling a ground wire after the
horn rather than the more common usage for controlling a power wire
before the power consumer. Electrically it amounts to the same thing but
people visualize it differently.

Mark

Jim Felder wrote:
> Mark, this is what I used on my recent lighting installation.
>
> On a late model VW Vanagon, there is a "double" relay socket that's nice to
> have to set up a few of them. But the ones with a tang or bracket build
> into them are nice because you can buzz one into sheetmetal (with the 85
> pin grounded to the screw) anywhere you need it, as close to the device as
> you want to put it. Then you can use the "old" hot wire to the device as
> the trigger wire going to 86.
>
> Another advantage of the design with the built-in mount is that you can use
> regular old female spade connectors on the ends of your wires instead of
> having to locate and purchase the special female spades with a locking tang
> on them that keep them from falling out of the socket that you need with
> the kind without the built-in mount.
>
> Jim
>
>
> On Wed, Aug 21, 2013 at 5:03 PM, mark drillock <mdrillock@cox.net> wrote:
>
>> The horn relay is nothing special, just a generic "bosch style" 4 pin
>> relay. Every VW has a couple and many other cars do too. VW refers to
>> this one as Type 53 or 24 and stamps that number on the top in big type.
>> You can buy the generic version at any flaps, often sold as a fog light
>> relay or horn relay, or driving light relay. Commonly used as fuel pump
>> relays as well, as in Vanagons. Typically 30 amp, sometimes 20 or 40
>> amp, all more than enough for horn use. Sometimes the generics have a
>> 5th pin that isn't used for what I did.
>>
>> The 4 pin relay has pins labelled with numbers and is used thus:
>>
>> 30  load in
>> 87  load out
>> 86  relay control input pin
>> 85  relay control ground pin
>>
>> Mark
>>
>>
>>
>> Marco wrote:
>>
>>> Thanks for the tips, Mark.  I have ordered one of those Hella horns from
>>> the eBay vendor.
>>>
>>> Do you have a part # or source for the relay? I couldn't find it in the
>>> archives.
>>>
>>> Thanks,
>>> Marco in Seattle
>>>
>>>
>