HowTune

Hotwiring The Intercooler Pump on a GMC Syclone

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The ECU controls the IC pump on our trucks. The stock chip turns the pump on based on engine coolant temperatures.

To aid in cooling and prevent the IC from heating up during warm up, most owners hotwire the IC pump so that it is always running.

With this simple mod, when the truck is in the on position, the pump runs. This is ideal for stock chipped trucks, and essential for stock chipped trucks with a lower temperature thermostat.

Gain Access to the Intercooler Pump Relay

1

The IC pump relay is located on the firewall, behind the upper intake. It is grouped together with another relay. It's the one furthest to the driver's side of the two relays.

Image 257 from Hotwiring the Intercooler Pump on a GMC Syclone
2

Remove the two screws that hold the relay bracket to the firewall.

Image 254 from Hotwiring the Intercooler Pump on a GMC Syclone
3

The bracket has a metal black clip that you need to pry up to slide the relay off. Press it in using a small flat head and slide the relay off the bracket.

Image 251 from Hotwiring the Intercooler Pump on a GMC Syclone

Add a wire to ground the relay on

4

Separate the top (the relay) from the bottom plug of the housing.

5

Locate the relay terminal that the yellow wire runs to and wrap/fold a short length of wire around the relay terminal blade.

6

Reconnect the two halves of the relay and cut the wire to the length needed to run to a ground. Any of the screws that go into the firewall should sufficiently ground the relay to keep the pump running.

7

Celebrate!

There are 3 Comments.

Say Something.

What temp does the ECU turn on the pump on a stock chip truck?

reply:

The stock chip turns on the pump when the coolant temp reaches 180 degrees F.

Ok thank you!

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