Aftermarket Horn Problem in Renault Duster. Help Needed.

[kanishka]

Hello this one is for the electrical Gurus here. I have a 2013 Renault duster 110 with ABS. The car came with a single horn which was very weak and it was very dangerous to drive the car on highway using the same horn.

So I decided to change the horns, in 2013 renault was not offering any upgrade for the horns so decided to go the “Aftermarket” way, went to a accessory shop and got a pair of BOSCH horns for my ride…


Everything went smooth till few days back, my horn started to give troubles. It was working in an erratic way, went back to the accessory guy asked him to check it.
He checked the connections which were fine, and advised me to go to the company service centre to get the switch checked..

The service centre guys found the switch faulty, now the air bag version of duster has a rotary switch for solving various purposes which includes the connection of ABS, Indicator switch, Switch for headlight, And the Switch for horn!!!!
This is the part I am talking about


Now the service centre guys told me that the rotary switch needs to be changed, which they would not be covering under warranty because I got the horn changed from outside.

Now the shocking part is the rotary switch itself costs Approx Rs 10,000(ten thousand)


So with a heavy heart I returned back…

Now I thought of repairing it myself thing of the worst case where Ill have to spend ten thousand bucks to get the switch changed!!!

So I thought to start with putting up a horn relay…

Bought a horn relay relay costing 100 bucks like this


Now it has three terminals named H B S
according to google and my knowledge
H is for Horn
S is for switch

B is for battery

So I wired it according to this diagram


To my surprise the horn did not function, at first I thought the relay to be faulty. So took out another relay from my Zen which was working perfectly working in there tried the same connection with it and again it did not function????

I used the positive end of the switch wiring to trigger the relay!!

I tried changing the connections and connected it in a way as shown

To my surprise it started to work flawlessly??
I am using this setup for three days now..

Now my query is
1) What can be the probable reasons the earlier setup was not working??
2) Am I doing any harm to my cars electrical system using this technique???

P.S I have added a 30Amp Fuse between the +ve of battery and the horn!!!!