5.3L (LM7) into OBS Sierra Classic

[80K25]

Ok, couple of questions:

1) Fuel Pressure Sensor. Does a guy need to install one, or can it be deleted?

2) Fuel level sensor, same as above, do I need it, or can I live with just the stock sending unit for my factory gauge?

3) Low coolant sensor. I noticed the truck ran in limp mode if it was disconnected, but I cannot find any mention of it on the ECM pinout... Is it something I need, or can I use my stock rad with the stock overflow bottle?

4) AC sensors. My cab does have AC, but I will not get around to hooking it up for a while. I again noticed the truck ran in limp mode if I disconnected either sensor... Is it something that has to be hooked up, or do I have to get it disabled in the prom?

5) Since my truck has a standard tranny, what kind of an input is the ECM looking for from the clutch safety switch? My truck does not have one...

Thanks!

Russ

[1BADC10]

<div class='quotetop'>QUOTE(SierraClassic &#064; Mar 7 2007, 01&#58;24 AM) [snapback]85546[/snapback]</div>

Ok, couple of questions:

1) Fuel Pressure Sensor. Does a guy need to install one, or can it be deleted?

2) Fuel level sensor, same as above, do I need it, or can I live with just the stock sending unit for my factory gauge?

3) Low coolant sensor. I noticed the truck ran in limp mode if it was disconnected, but I cannot find any mention of it on the ECM pinout... Is it something I need, or can I use my stock rad with the stock overflow bottle?

4) AC sensors. My cab does have AC, but I will not get around to hooking it up for a while. I again noticed the truck ran in limp mode if I disconnected either sensor... Is it something that has to be hooked up, or do I have to get it disabled in the prom?

5) Since my truck has a standard tranny, what kind of an input is the ECM looking for from the clutch safety switch? My truck does not have one...

Thanks&#33;

Russ
[/b]

Check engine light... uh... hmm... I haven&#39;t added that yet. I just keep my laptop handy when I drive the truck. Alternator light? When the volts gauge drops below 12V, I&#39;ll start looking to get to my final destination ASAP. I didn&#39;t make provisions for that. I did tie-in a diag port. There&#39;s a connector on the engine side of the harness that you can cut and splice in what you need. I found a descent interior harness off eBay, so I just used the stock connections.

Now... for fuel, I have an external mount fuel pump (255lph-rated) mounted to the frame rails. You may want to drop the tank(s) and drop in an in-tank pump. There is a p/n posted somewhere here, or on PT for that. Just be sure to replace any low-pressure fuel hose (rubber lines) with fuel-injected hose (or braided lines). If the 5.3L&#39;s intake has an integrated FP regulator, I don&#39;t "have" to worry about buying an aftermarket regulator. Let&#39;s not forget to install a filter in the line too. Low pressure filters will not due. Get a high pressure quick-connect or NPT-connection (screwed) type.

Your stock level sender should work well with most aftermarket gauges (providing you&#39;re going that route). I spent the extra on gauges b/c using the stock cluster with the paper element on the back would be a hassle to get it to work. Plus, to get an adaptor kit for the digi-to-analog speed signal would cost me the price of getting a complete gauge package. The aftermarket kit was what I wanted.

Low coolant... you will need to use the coolant bottle out of the NBS truck anyhow. The cooling system is a pressurized system. Transfer it over. Plus the connector is on the NBS harness.

Cannot comment on AC stuff b/c I have dealt with that issue yet. I am hoping to use the stock NBS compressor, but the in-cab component uses solenoid to force air to close valves to regulate switching functions for heat, max AC, low AC, and econo-mode (vent). I haven&#39;t put much effort in researching this since the truck&#39;s been down for a while.

Clutch Safety Switch - I am assuming this is a function that prevents you from starting the vehicle in gear. Is this not like the P/N safety switch? Does the donor rig have an A4 trans? If so, I&#39;m sure that is what that&#39;s for. If not, I have no clue... maybe someone can help with that. If you&#39;re getting rid of the 4L60E in the donor (if that&#39;s what it has), wanna "donate" it to a worthy cause? Nevermind, it&#39;s a 4x4 trans. Couldn&#39;t use it anyhow.