[exv8man]

Can someone explain in laymans terms the purpose and necessity of relays. Like using a relay on an electric fuel pump. Thanks

 

[Pops @ Tri-5.com]

Exv8...Basically a relay is designed to handle high amp loads....Like the horns, a fan, fuel pumps, etc.....That way you can turn the equipment on and off with a low amp switch that controls the relay and in turn the relay turns the load on/off....Additionally the wire going from the controlling switch to the relay does not have to be as large a gauge.

 

[56Mark]

Here is a link that has some diagrams and at the bottom and explanation of why to use them, but pretty much says the same thing David did.

http://www.the12volt.com/relays/relays.asp

 

[BO185]

Paul, the relay allows the control of a high current draw of the fuel pump. The PCM provides 12v to the relay to tell the relay to close sending current to the fuel pump.

The 12v from the PCM isn't designed to handle that much of a load, hence the small size of the wire.

Oh did you ever get the motor to run?

 

[exv8man]

Reply to BO185

The motor turns and fires but I did not try and run it until I tie up some of these loose wiring ends. I hope to have a good running report this weekend. Let you know. Thanks all for the replys Paul