flasher relay behaving odd

Hello,
First post here, hope it is in correct section. I built a super cheap alarm for my car, triggered by the 'open door' wire from the dome light. This signal goes through my hidden switch, then grounds a time delay relay. The time delay relay sends a + signal to a 2 pin flasher relay. The flasher relay gives a flashing + signal to a 4 pin relay, which closes the ground side to horn. Horn is wired to + side of battery with large gauge fused wire. So horn should "flash" for 15 seconds after the open door is closed, and forever if it remains open.
Problem is, it is not "flashing". The circuit works other than that, meaning the horn relay gets a signal for 15 seconds after door is opened. How can the flasher relay let 12v flow through it, which it must for the horn relay to work, yet not flash? I used 3 different flasher relays and they all did same thing. Is something fundamentally wrong with my circuit?
Thanks!

There isn't enough load on the flasher to make it "flash".

Most flashers are capable of carrying the load of the horn directly, without a relay. Modify your circuit so that the time delay relay output goes to the flasher, then to the horn. Beware that flashers are polarity sensitive. They have an input and output.

Or add a couple of 1156 light bulbs to the flasher load. That will make it "flash".

Thanks! I simply put the flasher relay just before the horn, on the load side of circuit, and now it works like a champ.
Thanks again!