I am doing the fuel pump rewire mod and have a question about relays. I have an optima trunk mounted battery and a coolingmist AI trunk mount. I plan on using a Bosch type relay for each system. Can I use the stock wire going to the fuel pump to trigger both relays (1 for fuel and 1 for AI)? Will this draw too much current on the stock wire? I know the current draw on the relays are low but not sure how low.

 

You'd have to find draw from the electrical manual specs and reference that with the gauge of the wire. I think you'll be fine as that wire should have enough capacity to handle the draw adn the relays will be fine.

 

using the stock fp wiring as a trigger would be fine as the pump itself pulls over 8 amps.

 

all the trigger does is power a coil inside the relay to close the circuit between terminals 87 and 30 (on a 4 pin relay). i bet it only pulls a few milliamps.

 

+1.
You'll be fine, the stock pump pulls way more then a couple relays will.

 

Thanks for the info guys.

 

You can use the stock wires to turn on the relay. Will not hurt a thing.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fuel-pump-rewire-drawing-773489/


Also your "coolingmist AI trunk mount" don't most of these come with some sort of boost switch/relay so that the pump isn't running all the time.

 

Yes, the AI system has a boost switch. But I don't know if its a switch or a relay, I have not looked at the diagram to see how it works. If it works like a 4 pin relay, then I could eliminate the need for one of my relays. If it is a simple 2pin that doesn't shed the load off the input signal, then I am back to the 2 relays. Ill look at it and let you know how it is setup.