2001-2004 LB7 DSP5 Switch Installation.

This article will explain how to install your LB7 DSP5 switch.

Switch Installation 


1. Open your hood and locate your ECM.

ECM can be found near the battery located at the front driver side of the engine compartment.

Make sure you do not remove the TCM unit marked Allison on the driver side fan shroud.


2. Disconnect the ECM connectors from the ECM.

You will need a 7mm socket to remove ECM harness.


3. Locate the hood release grommet found on the driver side firewall.

It is a small rubber grommet located roughly 6 inches down from the hood at the firewall and 4 inches to the left of the driver side fender.


4. Pull the grommet out.

5. Run your guidewire through the hole into the cab and locate the guidewire under the dashboard.

6. Use electrical tape to secure the DSP5 wires to the guidewire.

7. Carefully pull the guidewire through the hood latch hole into the engine compartment. Make sure that you have enough wire on the engine compartment side to run the wires into the                 ECM harness.

8. Use the conduit provided with your DSP5 switch to protect the switch wires from heat.


9. Carefully put the hood latch grommet back in place around the DSP wires.

It helps to make a small cut in the grommet for the wires to run through.


10. Now locate the blue connector on the ECM harness. Use a small flathead screwdriver to remove the top gray cover. 

Be gentle with this piece it is prone to breaking and can be difficult to remove at first.


11. Once the gray protector is removed find pinhole #49 and pinhole #69.

If you look closely you will see the numbers printed on the ECM connector.


12. Now remove the blue covers on the wire pin side. Do so by using a small flat head screwdriver to push the tabs in on both sides of each blue cover.

13. Locate the Pinholes that the switch pins will go into, hole #49 and hole #69, and install wires.

It does not matter which color wire goes into which pinhole.

Make sure that they push all the way through and lock into position so they appear just as all the others do.


14. Put the blue covers back onto the ECM harness.

15. Reconnect the gray cover on the top of the ECM harness.

16. Reconnect the ECM harness to the ECM.



If you are still having issues go to the DSP5 Switch Trouble Shooting section.