LSA Intercooler Wiring

[joeko23]

Trying to wire the intercooler pump from my LSA. I have a PSI engine harness which has a (pink wire) for intercooler trigger it’s a ground wire. PSI sent me the below pic on how to wire the relay but I’m still confused.

The intercooler pump has a positive and negative wire.

Is this correct?
Pink ground trigger goes to 85
Positive wire from intercooler goes to 30
12V ignition source goes to 86
Power wire from battery goes to 87(where do I get this from? Starter or alternator?)

What do I do with ground wire coming out of intercooler pump? Does that tie together with pink ground wire that goes into position 30 on relay? Or am I connecting it to an actual ground on the frame?

Also if I have a 12v ignition source why is another 12v battery wire needed? Is that just to power the relay?

[dhutton]

I am a little confused but that wiring diagram is not using the pink wire from your ECM to trigger the pump. Not a big deal, just confusing. It will work fine. I embedded comments below.


Trying to wire the intercooler pump from my LSA. I have a PSI engine harness which has a (pink wire) for intercooler trigger it’s a ground wire. PSI sent me the below pic on how to wire the relay but I’m still confused.

The intercooler pump has a positive and negative wire.

Is this correct?
Pink ground trigger goes to 85
No it is unused as near as I can tell. Switched ignition goes to to 85.

Positive wire from intercooler goes to 30
12V ignition source goes to 86
Power wire from battery goes to 87(where do I get this from? Starter or alternator?)

I would connect it to the starter since you refuse to have a battery junction. I have to say as an engineer I tend to shy away from this sort of form over function thinking. I always have a battery junction post under the hood on cars with trunk located batteries.

What do I do with ground wire coming out of intercooler pump? Does that tie together with pink ground wire that goes into position 30 on relay? Or am I connecting it to an actual ground on the frame?

Ground it to the frame.

Also if I have a 12v ignition source why is another 12v battery wire needed? Is that just to power the relay?
They are trying to avoid overloading the switched ignition circuit with the pump
current. Make sure you fuse this connection.


One other comment. It is highly unusual to use pink for a ground trigger. Please post the documentation you have that says the pink intercooler trigger is a ground trigger.

Don

[protour_chevelle]

Trying to wire the intercooler pump from my LSA. I have a PSI engine harness which has a (pink wire) for intercooler trigger it’s a ground wire. PSI sent me the below pic on how to wire the relay but I’m still confused.

The intercooler pump has a positive and negative wire.

Is this correct?
Pink ground trigger goes to 85
Positive wire from intercooler goes to 30
12V ignition source goes to 86
Power wire from battery goes to 87(where do I get this from? Starter or alternator?)

What do I do with ground wire coming out of intercooler pump? Does that tie together with pink ground wire that goes into position 30 on relay? Or am I connecting it to an actual ground on the frame?

Also if I have a 12v ignition source why is another 12v battery wire needed? Is that just to power the relay?

All they are saying is that the ECM sends a ground signal to activate the relay to turn the pump on. Much like the electric fans on stock ecu setups.

Ground the pump to the chassis.

In regards to the 12v ignition source, my understanding why they do that is, without the key on power, the relay does not have the ability to turn on when the ground signal is sent. Hopefully that makes sense.

[dhutton]

:confused:

Don

[joeko23]

188829Here’s the documentation:

[dhutton]

188829Here’s the documentation:
There you go. Really poor choice of color imho. I have no idea why the ECM needs to control the pump. I just turn my on when the car is running.

Anyway you could connect this to pin 85 of the relay instead of connecting it to ground if you like. The pump ground still needs to go to chassis ground.

Hope this makes sense.

Don

[brent1976]

You need to run heavy gauge wire to 87 with a jumper wire to 86, pink from PCM to 85, heavy gauge wire intercooler power to 30, and ground intercooler to chassis.

[joeko23]

Why do I need heavy gauge wire? The stock intercooler pump wiring is maybe 16 or 18awg. Also the intercooler pulls around 5amps. Stock zl1 has a micro relay with 10 amp fuse.

[brent1976]

I thought I remembered my buddies 03 cobra had 8 or 10 ga wire suggested. Maybe because it had a bigger aftermarket pump for a huge tank in the trunk. Use whatever the pump requires and you think is right. I always use at least one wire size larger than a pigtail is.