Fuse Block Replacement on my 320

[jimbar99]

The fuse block in my 320 was corroded and the fuse clips had lost their temper, making the electrical connections through the fuses unreliable and possibly dangerous. In fact, the corner of the original fuse block cover was somewhat melted - a sign of trouble ahead.

 

Disclaimer - Don't try this at home. Making a mistake could result in a vehicle fire or worse. This is just documenting what I did for my own vehicle, not saying it's the best solution but it worked for me. If you try something like this, do so at your own risk. Now, the project...

 

 

I decided to replace the fuse block with an aftermarket part that uses ATC blade-type automotive fuses instead of the glass type, and has more capacity for future circuit add-ons. Of course I kept the original in case I want to go back to it someday (NOT).

 

 

 

After searching around a bit, I found the Blue Sea #5029 fuse block meant for marine service. It has 12 circuits with 30 max amps per circuit, and 100 amps max for the entire fuse block. While the existing wiring might not support these levels of amperage, I was satisfied that this fuse block would be at least adequate, and much better than the stock block even if it were brand new. It comes with some adhesive backed labels for boat related stuff. I might put those on just to confuse people.

 

 

The only problem with using the Blue Sea block directly is that it has one power feed terminal that feeds all 12 of the fused circuits, 6 per side as shown in the next pic. It's really meant to be a power distribution block for auxiliary stuff. My stock fuse block is such that 2 of the fuses are powered from the battery, i.e. the key doesn’t have to be on for them to work, and the other two are only under power when the ignition key is on. That functionality is not possible using this new fuse block, at least not without some modifications.

 

 

 

The next picture shows the power distribution buss bar that runs the length of the fuse block just beneath the cover.

 

 

I wanted half of the fuses to be powered from the Main Power terminal, and the other half to only be powered when the key is on. To do that, I needed to sever the buss bar into two segments.

 

I removed the back of the fuse block to expose the buss bar, and found a good spot to cut it in two between fuses #6 and #7, without getting close to the fuse clips that have to grab the spades on the ATC type fuses. I used a Dremel tool with a metal cutting disc on it. If you try this modification, you might want to drill the mounting holes before you sever the buss bar. (see the next step)

 

 

The middle of the buss bar is loose where it was severed, so I drilled a couple of holes and used a small machine screw, washer and nut to secure each cut end of the buss bar. I also used a couple of spacers on the back side of the fuse block to make sure that the buss bar lined up the same as it did before cutting it in half.

 

 

 

Drilling the holes before severing the buss bar would be a smarter move, and make it easier to see what spacer thickness you will need to make it work.

 

 

Here is how the fuse block looked after I got it installed in the truck. Keep in mind that the heads of the screws that I used to secure the ends of the buss bar are live, so be careful not to create any short circuits. I intend on covering them with some liquid electrical tape to prevent inadvertent shorts in the future. They will be somwhat protected by the plastic cover when it is in place, but it never hurts to error on the side of safety.

 

 

 

The bottom 6 fuses are powered by the fat white with red stripe wire at the center terminal. The top 6 fuses are powered by one of the black and white wires that comes from the ignition switch. The power passes through a 30 amp fuse in this case, to the top half of the severed buss bar, and powers the rest of the upper circuits on the fuse block.

 

 

 

Powering all of the ‘key on’ circuits through the key switch seems like a bad idea, so this is a prime candidate for a future relay. Then, the key switch will only turn on the relay, and the relay will switch power to the ‘key on’ circuits instead.

 

 

While not waterproof, the included cover helps prevent splashes from getting on the fuse block and possible causing corrosion that will lead to future electrical headaches. The cover includes storage for a couple of spare fuses as well, although none are shown in this photo.

 

 

I’m sure that Blue Sea would not condone modification of their fuse block like this. You are taking a chance any time you modify a component from its original design. Therefore, I have to recommend that you not do this modification unless you have experience with electrical systems and are confident that you will not create a shock or fire hazard in the process. It's working great so far. Next step is replacing the generator with an alternator, adding the 'key on' relay, and converting to H4 halogen headlights with relays controlling the headlight power.

 

Let me know if anyone has any comments or spots any corrections or improvements that need to be made.

[Charlie69]

Great write up. Thank you for the time you put into the pictures & write up.

[wayno]

Very good article.:cool:

[burrito213]

the technicians at my job recommended this as they buy a lot of products from west marine for automotive use.

 

great info and great thread.

 

i am assuming you are running a 12v neg. ground system for your truck? do you still have spares for running extra stuff too?

[jimbar99]

the technicians at my job recommended this as they buy a lot of products from west marine for automotive use.

 

great info and great thread.

 

i am assuming you are running a 12v neg. ground system for your truck? do you still have spares for running extra stuff too?

 

Thanks.

 

Yes, it's 12V negative ground. I converted it a couple of weeks ago. Although you could do this with positive ground as well, but hook the negative power feed to the bottom terminal on the fuse block instead of the positive power feed.

 

This scheme gives me 6 available terminals in the "always on" section, and 5 in the "keyed on" section (one of the 6 is used for the feed wire from the ignition switch). I could have cut the buss bar in a different place and had, for example, 4 terminals in the "always on" section and the rest in the "keyed on" section. I'm not sure what my plan is for electrical accessories right now, so I cut it in the middle. If it turns out that a different scheme would have been better, I'll buy another fuse block and do it differently. The fuse block was around $40 I think. The company that made this fuse block has several other options that might be better for a particular application. This one seemed to suit the bill for what I was trying to do.

 

A change from generator to alternator is in the planning stage so I will have enough power to distribute through the new fuse block! As soon as I figure out which alternator to buy that is. Any ideas on which internally regulated alternator makes a good choice?

[bilzbobaggins]

Awesome write up!! I did something similar on my 521 with cheap one from autozilch.

 

Thanks

 

Jeff

[zenndog]

Another great write up. Thanks. Z

[Zeke- Aus- Li]

awsome write up..

[ppeters914]

Hate to clutter up your thread, but excellent write-up. The way they all should be done.

 

A change from generator to alternator is in the planning stage so I will have enough power to distribute through the new fuse block! As soon as I figure out which alternator to buy that is. Any ideas on which internally regulated alternator makes a good choice?

Still running the stock E1 engine? The popular/common alt upgrades are GM, Saturn, and KA. Key thing is getting the pulleys aligned for the belt, which usually means modifying the existing bracket or fabricating a new one. Here's one thread (that includes links to other threads) to get you thinking:

 

Alt upgrade my way

[jimbar99]

Hate to clutter up your thread, but excellent write-up. The way they all should be done.

 

 

Still running the stock E1 engine? The popular/common alt upgrades are GM, Saturn, and KA. Key thing is getting the pulleys aligned for the belt, which usually means modifying the existing bracket or fabricating a new one. Here's one thread (that includes links to other threads) to get you thinking:

 

Alt upgrade my way

 

Thanks. I used to be an Instructional Designer before I became self-unemployed, mainly designing instructional materials for high tech industrial processes. I would have included more photos of the process but I didn't decide to document it until it was already done.

 

I have the E1 engine but I bought an L16 with 4 speed on Craigslist for $100 and am thinking about squeezing it in for a future project, but the alternator upgrade for the E1 is definitely the next project. I will need it for the H4 Hella halogen headlights that I already bought. Thanks for the link!