Dual speed fan relay wiring.

[LewisT]

Hey every one i have designed a small circuit for controlling the dual speed radiator fan on my saxo and need some input on my design whether it has any faults or if it should replicate the existing functions, this change was necessitated due to buying some waterproof relays to replace the current one on the car that fail due to water ingress, problem is the current relay is a 5 pin double output where 87/87b are normally open and the waterproof ones i bought are 87 no 87a nc and they don't seem to be available in the double output type.

Below is a sketch on the left is the original wiring and the right is my proposed wiring for the new relay.

Sorry for the poor sketch thanks for looking.

 

[m_c]

What you're proposing should work, although I am wondering why Renault choose to do it that way.

The only thing I can think off, is with the original setup, when activated, the relay is essentially just bypassing the resistor, but with your proposed setup, it'll essentially be disconnecting the resistor briefly before applying full voltage.
Provided the original relay is a twin output (aka both pins are wired together, unlike a double output where the pins are only connected when the relay is activated), then I'd just wire the resistor and fan into the single NO output.

 

[LewisT]

What you're proposing should work, although I am wondering why Renault choose to do it that way.

The only thing I can think off, is with the original setup, when activated, the relay is essentially just bypassing the resistor, but with your proposed setup, it'll essentially be disconnecting the resistor briefly before applying full voltage.
Provided the original relay is a twin output (aka both pins are wired together, unlike a double output where the pins are only connected when the relay is activated), then I'd just wire the resistor and fan into the single NO output.

I checked the relay its twin output, as to why its french. i did think of wiring as you suggest but the relay has a rubble seal on the bottom with 5 holes in it lol they are available in 4 pin though.