Multiple relays sharing same output?

[DanGT4]

This is probably a really basic elelctrical question for some of you, but is it ok to wire two relays so that they are controlled by the same output on the SM4?

Thanks,

Dan.

[underpsi68]

Sure. There is no load/amps on the realy trigger wire.

[MRMRacing]

Yes you have the load SM4 O/P can handle in manual or in software. But sometimes it needs diodes. If connecting two relays bot the 12 volt and other side to SM4 O/P. Then current will float thru the relay coil to the other relay meaning you will get 6 Volt over that relay, it may not be so much it will enable but enough to hold enabled when Sm4 O/P is turned off!

[gsportcars]

I am re-wiring my fuel pump/injector output trigger from the SM4 to switch two seperate relays rather than the single relay for both injectors and fuel pump. I have replaced the fuel pump relay three time now and it is starting to give trouble again. I think that the current of the fuel pump and the injectors together is maybe too much for the single relay and it is causing it to fail after so many hours of use.
I will be simply employing a second relay for the fuel pump that is also triggered from the SM4 but will power the fuel pump alone. The original Relay will power the injectors.

[MRMRacing]

If you got more O/P you can use another O/P for the new relay, or se a diode on one relay or both!

[gsportcars]

Yes I still have plenty of outputs. That is a better idea. I am assuming then that using another output will still kill the power to the pump relay if the engine stops?

[underpsi68]

I am using the factory Autronic relay to give power to the injectors and than use that same +12v output to power (trigger) another Bosch 30amp relay to my fuel pump. 1 1/2 years no problems at all.

[MRMRacing]

Yes I still have plenty of outputs. That is a better idea. I am assuming then that using another output will still kill the power to the pump relay if the engine stops?

Yes you can set the O/P fuelpump to one of the "m" marked O/P. For example Sfw PWM 2, press enter and go then to the right to O/P pin ans press enter, select then the two O/P you want by pressing spacebar. You have now selected on O/P fuelpump to two physical O/P´s. This is also done when you want to increase the current for one O/P if your load is more than one O/P can handle.

[gsportcars]

Cool thanks.