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Discussion Starter #1
OK folks, this isn't the first time I've done something dumb but may be near the top...
My 88 sammy isn't my main set of wheels so it sits for long periods of time. After the last time I drove it I was playing around and I connected a power inverter to the battery just to see what I could run with the new deep cycle battery. Well, I somehow blew the main fusible link. First time ever. I replaced it with a plain old APR fast acting 25 amp blade fuse. Once I start to crank it over, it blows. I've tried a 30 and they blow. They will also blow once it's been running for a few seconds, but the engine still continues to run and will run until I shut it off. I then need to replace the fuse to start it again. I can tell when it blows because for a split second the wipers move and I think the lights blink. As long as the engine is running, all still work.
My questions are:
Did I fry something else? Should I use a slow blow breaker instead? Anything else I can check/do? How large of a fast acting fuse is safe?

any help would be great!

thanks,
george
 

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Any particular reason you're not replacing it with the OEM part?
 

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Discussion Starter #3
Sounds too easy...
I don't have one, and the last time I contacted the dealers around here, they acted like I asked for a part for a 59 chevy, and everything, _if_ it's available is special order only. Local salvage yards all say they got rid of the sammies a long time ago.

thanks,
george
 

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What is the output of your alternator?

Use a fuse with an amperage at least equal to 80% of your alternator's output - if I were to use my Swift as a reference I'd say you need something in region of 60A.
 

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with those calculations, you should be ok with a 32 amp fuse on your 40 amp alternator. That fusable link is the line to the batery from the alternator for recharging the battery. If you increase your load on the alternator you will have a higher output to that fuse. That's why a lot of people that run winches or welders or other high power draw gear go with a replaceable fuse. Not only does the higher output alternator put a larger load on that link but the capacity to blow that link increases with things like a winch pulling power and stepping up the alternators output. If you do decide to use replacable fuses, you shouldn't go over the wires load rating or the batterys recharge rate. You can start an electrical fire in your insulation or ruin your battery, and it's a whole lot easier and cheaper to just replace a fuse.
 

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I believe the Samurai alternator is rated at 35A. With stock wiring, all the alternator charge current flows through the fusible link. Also, all the electrical system current flows through the link, from the battery and in the other direction, when the alternator is not running (it's the way it's wired, and not a defect).

Fusible links are VERY slow-blow fuses. On my rig, I would prefer to replace it with the OEM part, or near equivalent. But, if I had to use a fuse instead, I'd use a 40A MAXI fuse. They are a lot slower than the smaller types. You are protecting the vehicle wiring, which is a slow-blow application. MAXI fuses have replaced fusible links in many late-model vehicles (although they do not have the same performance characteristics).

If your battery is not fully charged before you begin, the full alternator charge current flows into the discharged battery, though the fusible link, as soon as you start, which is what may be blowing your fusible link/fuse.

High-current alternator upgrades REQUIRE a separate, #6 (or larger) alternator charge wire directly to the battery to prevent blowing the OEM fusible link. The existing OEM alternator charge wire is simply taped off and no longer used. The OEM fusible link protects your vehicle's wiring. One electrical fire could ruin your whole day.

Edit: Added a Fusible Link Color & Ratings chart at: http://www.suzuki-forums.com/gallery/images/45520/1_Fusible_Link_Info.gif . The Samurai uses the green 0.5 square mm link.
 

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Discussion Starter #7
I wanted to make sure things were good before I posted again. And thanks for all the postings.
I ended up using a 30amp breaker in the fuse holder and all is good so far.
I kinda had a feeling the fuse was just too fast. I remember reading in the Haynes book the OEM is rated for 30amp.
The more recent postings about running a wench and more draw, larger alternator, etc. does interest me as at one time I did have a Ramsey #8000 on it and do run a plow now. (I'm in DE)
I've let this thing sit for too long between driving it and now am starting to remember all the things I wanted to upgrade... I remember seeing the thread on GM alternators and that's now a must. (I'm running a 1.6 sidekick engine with the sammy alt in the sammy)
So, I'm going to need larger gauge wiring from the bat to the alt. What else? Is there a better way to wire things?

Now my needs will be a new larger gas tank, but first a new main heater core and wiper motor...
But all that is for a new thread.

thanks,
george
 
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