Wiring Harness & Modern Fuse/Relay Block

[bkreutz]

I think a 145A fuse between the alternator and the fuse block is like not having a fuse at all. You want to rate that fuse a bit higher than the output potential of the alternator/generator you have. So unless you have a fire truck alternator adapted to your engine() it needs a smaller fuse (one with less capacity, not physically smaller)

[mongoswede]

I think a 145A fuse between the alternator and the fuse block is like not having a fuse at all. You want to rate that fuse a bit higher than the output potential of the alternator/generator you have. So unless you have a fire truck alternator adapted to your engine() it needs a smaller fuse (one with less capacity, not physically smaller)

I think the aluminum in your rover will catch on fire before a 145A fuse will blow

[printjunky]

Yeah, 145A is crazy. It's the highest main fuse I've seen on a regular pass. car. And this Caddy probably had a 100A alt, max, I'd guess. Not sure I understand how it fits into the design ... anyway, it's probably a little overkill to even have it in the Rover, if I'm going to fuse everything else, but I can easily downrrate it.



Greenmeanie, I never went for my A&P, but I spent a few years working on jets in the Air Force. And then a bunch of years as a stagehand (soldering mic cables, and such). So while I may forget to slide the shrink wrap on before making the joint, and very occasionally immediately forget the second time (by very occasionally, I of course, mean earlier this week), I've put some irons to the wire.

[printjunky]

I was wrong. The main fuse in that box is 175A!

Tony, you OK with me documenting my upgrade here under this appropriately title thread you started, or want me to start another? Your thread, your choice.

[amcordo]

I was wrong. The main fuse in that box is 175A!

Tony, you OK with me documenting my upgrade here under this appropriately title thread you started, or want me to start another? Your thread, your choice.

BAHAHA I definately lost the right to tell people not to hijack my threads...

Perfect place to post the ways you're doing it! More learning for everyone.

[kevkon]

And as to the free advice for the 'BEST' method of making joints -both solder and crimp have their place but providing strain relief to the joint is the most important factor to its longevity. As to which you should use, try practicing both methods and find out which you are best at. Dealing with aircraft power systems I can say that very few people who don't hold rating tickets can do a truly good solder joint.

I agree, but most of the problems I have encountered with auto wiring have been related to bad crimp connections. Proper crimping is a skill and requires the proper components. Too often people use the incorrect connector or crimp the connector incorrectly. The worse thing about this is that it is usually responsible for the dreaded intermittent electrical issues.
I think that a person who is willing to solder is a person willing to spend more time and is probably more likely to be careful.
For anyone not comfortable with soldering or crimping, consider using the Posi-Lock and Posi-Seal connectors.

[jac04]

..consider using the Posi-Lock and Posi-Seal connectors.

I used the Posi-Seal connectors for the rear lights on my Lightweight. They work well, but are expensive.

[mongoswede]

I agree, but most of the problems I have encountered with auto wiring have been related to bad crimp connections. Proper crimping is a skill and requires the proper components. Too often people use the incorrect connector or crimp the connector incorrectly. The worse thing about this is that it is usually responsible for the dreaded intermittent electrical issues.
I think that a person who is willing to solder is a person willing to spend more time and is probably more likely to be careful.
For anyone not comfortable with soldering or crimping, consider using the Posi-Lock and Posi-Seal connectors.

A good crimp connection with a proper heat shrink seal will work just as well as a good solder connection. In some applications the solder connections are not advisable because vibration can fatigue the solder and cause it to fail. You want to spend the money on the good crimp tool and the good crimp connectors when possible. The kind the rolls both sides of the crimp inwards as opposed to the kind that just flattens the barrel.

[kevkon]

You can also have the best of both worlds by using a Crimp Solder Seal Heat Shrink connector. You crimp it and heat it which melts the connector and the shrink casing. Tht provides a sealed connection with strain relief. One thing though, be careful not to mix these up with the shrink- crimp only connectors which look similar but don't have a fusible ferrule that melts.

[printjunky]

OK, here's the fusebox I found, that I think will work. Obviously I'll replace those 40s with whatever's appropriate. I want to fuse everything, and any future adds, so my target was 20 circuits. This has 22 or so (the blank spots have no fuse sockets)

I guess I have to decide how to integrate the switched/unswitched circuits, as this box just has the main power in on one rail, through the fuses, and out to whatever, so it can't be both as far as I can tell.

Maybe I'll keep one side on the Lucas box ... So what's not switched?

- Headlights
- Flashers
-

Hmmm, can't think of (or see on the schematic) anything else. Any other candidates?

And there's no reason I couldn't put the headlights on the switched side, and I keep the flashers on their own unswitched circuit right?

[printjunky]

Oh, and the horn.

(and the inspection sockets which were always going to be switched and getting fused, of course (plus I'll be adding 2 modern power outlets to the emergency flasher center dash thingy))

[printjunky]

OK, here's the fuse box diagram, all mapped out and double checked.

I haven't really assessed it too much to see what kind of design might be best, except to note some possible relay usage for my headlights. (remembering I have 4 headlights - ie: left hi beams 60w/13.4v = 4.5Ax2 = 9A, etc).

I was thinking of ganging all 4 hi beams (18A), and all 4 low beams (16.4A) on just two relays, but I figure the more redundancy, the less likely I'll lose entire systems or sub-systems).

I also have to figure out how those other sockets fit in. I'm guessing those are also relays. I'll look up the part number (Bosch units) when I get home.

My wire length to the dash is about 36 inches, so hopefully I can design the rest and start soldering in extension wires tonight. Maybe mount the bracket on the firewall, too if I can beat prime mosquito time.

[JackIIA]

Nice looking diagram. What did you use to create that.

[printjunky]

Thanks. I should have opened it up a bit more, left myself more room to label. I used Adobe Illustrator CS2. Any moderately advanced vector graphic program can do the same. One of my interns uses a similar open source (read: free) program called Inkscape. I just installed it this week at home to see how it compares.

[printjunky]

So it took pretty much all day to figure out how I was going to mount the box to the firewall. I ended up having to modify the fuse box bracket, and I'll have to do a little rerouting of the heater hoses. They were a problem, because I have an aux heater that taps off of the heater hoses near the spot I want to put the box. Pics show my aux heater hoses going into the cabin, and the "H" that tees off to the aux hoses.

I didn't get a before picture of the bracket, but made a quick drawing of what I modified. The drawing is looking at the end of the bracket/fuse box.