Fitting 35’s with minimal trimming NOW ADDING LONG TRAVEL AND 934 CV’s

Thanks, I’ll check there Do you know if that box supposed to be grounded, I have it mounted, but it would be a poor ground

 

Looks as if just bolting it to the fender is good enough. heres a check for it out of the FSM

 

You really have to do a fair bit to make these fenders ground well. I found that out first hand. Aim for .5 ohm or less from negative battery terminal to any point On both inners, The core support and the body of the truck, as well as the frame.

 

it tested within spec, dang that would have been easy

I ran 4 gauge wire from the fenders to the frame, it’s still possible the frame side has a bad contact. But would a ground cause the efi fuse to keep blowing?

Is it possible that a wire came loose from the fuse box from getting moved around?

 

I dont think my buddy ever did an ohm check on his. just replaced it because of signs of arcing near or on the plug. But his was intermitent fuse blowing. Happened mostly when he went wheeling and was bouncing around he kept spare fuses for awhile until we chased down the issue after seeing the burnt wires

 

Gotcha, no arching, and the fuse blows just from turning on the ignition, truck actually runs, just super rich

 

Resistance creates heat. So a poor ground can in fact cause a fuse to pop. Only way to check is with a multi meter. You need to go from negative post to the inners, to the frame and even to the engine. If you haven’t done anything to improve your grounding situation on the inners I’ll bet money it’s your issue. 1/2 ohm or less. Nothing more.

Need to remember, many things use the body, the engine and the frame to pull ground from. You just cut your main ground supply off and reattached something in place of it. Nobody should be skipping over checking resistance at grounds after doing this. Even a slightly high resistance, say close to an ohm can and will kill components over time.

 

This is good advice. Maybe even to add in some ground straps to aid.

 

I’ll have to check the resistance tomorrow, I was super frustrated after spending all afternoon tracing wires, so I poured myself a top shelf Jack to relax me! I welded nuts to the backside of the inners where the grounds go and I did put 4 gauge between the inner fenders and frame, I didn’t do anything to the core though. I’m thinking that there is a short somewhere because the fuse pops when I turn the ignition on.

 

*takes notes*

 

I would disagree. While resistance above normal conditions can cause a myriad of problems, it does not pop fuses. A fuse pops from increase of current, or excessive voltage that it was not rated for.

Given, we are on 12vdc, only going to find the higher voltages in the secondary systems such as ignition or HID ballasts.

If a fuse is popping, you have increased current. Which per ohm law, means resistance is down.

I’ll agree that resistance creates heat, which is a form of watts. Only increases with higher voltage or lower resistance to increase amperage.

If his fuse is popping. My moneys on chasing a short to ground in parallel to the circuit or one of the circuits in question. Adding resistance in line will only decrease amperage.

 

This is for a 2013.

 

Is it just your 10 amp efi fuse? I’m assuming the 20 amp main fuse is okay if you’re still getting power to the 10amp. Though double check to rule out short to power conditions. The 10 amp circuit actually ties into several systems. I’ll have to post more diagrams later this morning. I kind of stopped adding screenshots based on the circuit for the fuel pump resistor.

 

Thanks for the schematics, it’s just the 10 amp, truck runs, just poorly because of all the systems it effects, just been tracing wires looking for a break

 

The efi 10 fuse seems to distribute power to some control side circuits for the air injection valve, control side to send power to the air fuel ratio sensors( primary o2 sensor heaters), and
Power to the secondary o2 sensors. Sorry if I missed something, I’m sitting in traffic. It would explain most of your thrown codes if not all of them.

It’s going to be a short to ground. You have a pinched wire or cut wire somewhere touching ground. The fact that you say it pops instantly when key is on tells me you have a hard short. It should be apparent when you find it. I see 3 relays this fuse ties into for the control side of other systems. If you can find a connector location table or diagram use the connector IDs on the wiring diagram to know which ones to disconnect. Isolation of the circuit into different sections will save you a headache.

I have highlighted all the “L-W” wires that branch off for this fuse.

 

Absolutely appreciate it, as soon as I saw the fuse pop with the ignition, I was thinking that it was a cut/broken wire in the system. Do you think all the movement of the fuse box could have loosened something up in there?

 

Disagree if you wish but a poor ground will cause a circuit to over draw. This is literally what I do for a living. See it time and time again where high resistance from a ground either kills a component or blows a fuse. It’s actually the second thing we check after we confirm the component it’s self is not the failure. Instantly popping is however usually a symptom of a direct short to ground. Usually being the key word.

Either way, my statement still stands. You cannot just bolt these fenders on and send it. If you did, I think you’ll be a bit surprised when you start checking grounds. I had to spend a pretty good chunk of time getting my grounding situation proper to body, engine and frame.

 

this is entirely too much math, science and factual information for this forum

 

The highest reading was .2 ohms and that was from the core