Formula_LT1

iTrader: (2)

When wiring up a LSx style harness does the fuse block need to be grounded? I have + battery voltage going to the fuse block and power to all the connections on the C1 and C2 block, but the C3 block is dead and it houses the fuel pump relay. When I turn the key to the "on" position I don't hear the usual "click" noise that the fuse block should normally make when you know its powered up like the one on my 5.3 truck does. Anyone that has any ideas please feel free to LMK.

bczee

iTrader: (12)

The fuse block itself is not grounded. .but the relay should have grounds. Check to make sure they are.

The Clicking Noise should be the relays getting activated.

MontecarloDrag

iTrader: (3)

Yes, the fuse block needs to be grounded. It has 2 places where you can ground it (top bolts on picture).

bczee

iTrader: (12)

The box itself is not grounded. It is plastic and would do no good grounding it to the battery/frame. What is connected to those Grounding bolt are the Relay grounds.

Depending on the application, the bolts might be connected to the frame or directly to the battery to provide good grounding for the Relay's.

Take the Box (underside) and follow the grounding circuits from the bolts to verify. They should be wired to the relay grounds or any other grounding circuits, but not any of the fuses or the Box itself (but if I am wrong, let me know.. wouldn't be the 1st time).

I have rewired my LS1 / F-body fuse Box, took it completly apart and move fuse, relay with what I needed and how I wanted them arranged.

From the diagram, there are 11 relays that would need grounds.

psiconversion

iTrader: (5)

Bczee is correct. You dont need to directly ground the relay box. Most EFI circuits are grounded by the PCM and the PCM is grounded through various pins which terminate, among other places, at the rear of the driver's cylinder head.

Jon
PSI

SurWagon

Sorry to threadjack,

Can someone point out where the positive and negative connections attach to the fusebox? My fusebox was from a 04 tahoe, and it looks like it's missing the max fuse (125A). I think that's where the main positive and negative go. The two studs flanking the high power fuses appear to be for auxillary circuits.

MontecarloDrag

iTrader: (3)

I always ground it and have had zero problems in all my swaps.

I agree you don't "have to", but it's a lot easier if you do. The first swap I did I didn't ground it and had a few issues, now I always do it and never had a problem again.

Formula_LT1

iTrader: (2)

I believe the main positive connection on the fuse box is not a stud but the bolt in connector on the left hand side of the picture posted above. Its actually a black wire on the truck harnesses but I'm not sure if the F-car setups are the same.