MSefi.com read only forum (Jan.15,2018)

Guru's, realizing this has been asked numerous times before...I read through the strings on related item but just to be sure because I am not an electronics whiz:

I want to control my fan relay with the fidle using my relay board/MS2: Wire the ground on the fan relay to pin 6 of the relay board?


sorry for the redundancy
ed

You could wire the relay coil ground to a ground anywhere. Ideally, you'd situate the relay close to the fan to keep the high current expensive fan cable to a minimum. So the relay coil could be grounded locally.

Dave, OK you lost me already. I am sure its me! More simplified question: I thought i connected pinout6 (fidle) on the relay board to the ground of the fan relay. When the ECU calls for the conditions to be met, it simply grounds the fan relay through the MS2? I am not using the fidle relay on the MS relay board as my fan relay.

ecorl wrote:Dave, OK you lost me already. I am sure its me! More simplified question: I thought i connected pinout6 (fidle) on the relay board to the ground of the fan relay. When the ECU calls for the conditions to be met, it simply grounds the fan relay through the MS2? I am not using the fidle relay on the MS relay board as my fan relay.

The experienced guys tend to talk in what I think of as "Fuel Injection Systems Shorthand". They know so much and they deal with it so often that, quite by accident, they talk over our (the newbies and less experienced guys) heads.

So, yes, you can use the MS2's FIDLE pin wire to control a relay for your fan. The relay on your relay board that was intended for the FIDLE can become your fan relay. That relay has 4 connections: 2 are for power delivery (12 volt supply and 12 volt output), and 2 are for the relay's triggering coil (a 12 volt supply and a ground, which in this case will be your re-purposed FIDLE control wire).

However... Using a relay located on the relay board for fan power could bring a problem to your system. The mentions that have been made with regard to mounting the fan power relay close to the fan itself is "Fuel Injection Systems Shorthand" for the consideration/concern that fans are notoriously noisy things (electrical noise, that is). They can feedback noise into your system so it's better to isolate them as much as possible from the wiring of the more electrically delicate parts of your fuel injection system like sensors (TPS, MAP, coolant temp, air temp) and the VR lines. Which, to simplify the whole thing, is to say that it might be a safer call to run a long wire from the FIDLE pinout6 on MS2 out to the location of the fan to trigger the coil of a relay mounted at the fan.

ecorl wrote:Dave, OK you lost me already. I am sure its me! More simplified question: I thought i connected pinout6 (fidle) on the relay board to the ground of the fan relay. When the ECU calls for the conditions to be met, it simply grounds the fan relay through the MS2? I am not using the fidle relay on the MS relay board as my fan relay.

Sorry to confuse you. I sort of thought you were using a relay on the relay board to control the fan relay.

Thanks guys....now I'm with you. I also read the amp limitations on the fidle board relay as well, thats why I wanted to just use the existing external fan relay. I'll just connect the pinout on the MS2 to the ground on my external fan relay ground. So, just out of curiosity, I guess connection pin6 on the relay board normally supplies power to the fidle?

ed