I recently installed a new fuel hat with larger pumps in my car and wanted to take the time to address the second pump running off a hobbs switch. I never liked that the second pump was triggered only when the hobbs switch was activated so a quick blip of the throttle and the secondary pump would trigger for a second and kick back off. Its hard on electric motors to just be flicking them on and off for short periods of time.
I set out looking for a timer relay that could keep the secondary pump running after its been triggered and I came across this relay.
Hella Adjustable Time Delay Units 996152131
The relay is adjustable and allows for a device to stay running after the trigger signal is gone from 0-900 seconds. Its also a simple 4 wire hook up like any other relay, the only thing about it polarity does matter on this relay vs your standard relay.
I hooked up the constant hot with key on to the hobbs switch as my 12v constant, I used the triggered side of my hobbs switch as my trigger wire, ground went to ground, and the output of the relay goes to the secondary pump. The result is that once my hobbs switch is triggered and shuts off my secondary pump continues to run for about 10 seconds. This way if you're changing gears, blipping the throttle, letting off to regain traction the secondary pump isn't kicking in and out constantly.
I set out looking for a timer relay that could keep the secondary pump running after its been triggered and I came across this relay.
Hella Adjustable Time Delay Units 996152131
The relay is adjustable and allows for a device to stay running after the trigger signal is gone from 0-900 seconds. Its also a simple 4 wire hook up like any other relay, the only thing about it polarity does matter on this relay vs your standard relay.
I hooked up the constant hot with key on to the hobbs switch as my 12v constant, I used the triggered side of my hobbs switch as my trigger wire, ground went to ground, and the output of the relay goes to the secondary pump. The result is that once my hobbs switch is triggered and shuts off my secondary pump continues to run for about 10 seconds. This way if you're changing gears, blipping the throttle, letting off to regain traction the secondary pump isn't kicking in and out constantly.
