i need help. what is the best fusible link upgrade? (1 Viewer)

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fj62max

Wildlife Customs
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Oct 31, 2007
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Iam having problems. about 4 years ago my factory alternator gave up. so went with mean green 120amp after a year it gave up. i tryed calling them and they have the wrost service every. so i just took it to a local alternator shop. Was working fine. Didnt use truck much after. started it and battery and brake light and buzzered also. I replaced battery still has same peoblem.
 
why do you think its a problem with the fuseable link?
 
I would like to start there. iam thinking of just getting the factory alternator repair and maybe have them rewind to 120amp
 
I think you would be well served to go over the whole charging system, checking wires and cleaning connections before throwing more money at the problem. A bad battery or crapped out charging wire is a great way to kill an otherwise working alt.
If the MG alt died due to a bad battery, of course replacing the battery wouldn't resurrect the MG alt. You may have just got a crappy MG alt, as I'm sure you suspect. I'd be pissed too after forking over big $ for a MG alt and have it last a year.
 
So what do you use to clean all the connections? Wire brush and some baking soda in water or what? Are there any connections that you should use some dielectric grease on?
 
next i will clean wires from alternator. when i rev up the engine the volts go up. and the battery and brake light, buzzed goes away. rpm goes down they come back on.
 
You can still get a factory fusable. Approx $30. You can test yours first with a multi-meter to see if it's working. Set the meter on continuity...and check each of the three wires.

Also suggest you check all the grounds in the engine bay. There are quite a few, but the one off of the battery, off the starter, the engine block and transfer are good places to start. Make sure they are clean, and solid.

No matter what, a battery is probably only good for 4 years.
 
fuseable links either generally work or they don't. I does not sound like to me that you have a fuseable link issue.

What is the output in volts on the alt with the engine running? You can check this with a multimeter at the battery.

What symptoms are you having?

When a fsueable link blows...generally you will have no interior lights but the truck may start and run..but there can be a number of crazy things that could happen if a fuseable links blows..

edit:... I had a fuseable link blow one time (I screwed up and did something stupid with the ALt wiring).....maybe I had interior lights but no power under the hood and no start.... either way I don't think the fuseable link is your issue and if it were you simply replace the thing (but you need to find out why it blew if in fact it did).
 
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A fusible link is... a fuse. It either conducts or it doesn't.

If your truck starts, the fusible links are functional. They may have increased resistance, but they are probably not your main problem.

"started it and battery and brake light and buzzered also."

The above would be more useful if expressed in English. I'm going to take a shot and guess you are saying that the battery light stayed on after starting? That means your charging system as a whole is failing to deliver 12v. Could be a bad alternator. Could be a bad battery. Could be a bad ground.

Solving electrical problems is a process of elimination. The first step is always to confirm the primary connections are clean and secure -- alternator to battery positive, battery positive to fusebox, battery positive to starter, battery negative to body/frame, block to frame ground, body to frame ground...

Then confirm the alternator is outputting at least 13.5v at the primary lug. Anything less suggests a weak alternator and/or failing voltage regulator.

If the reading on the alternator is good, confirm that the battery is getting the full output of the alternator. As wires age, resistance increases. It's not unusual to find that the alternator is putting out 14v, but the battery is only seeing 12v. That will not keep it charged.

The battery should be load tested. If it reads below 9.6v under load, it's weak and likely needs to be replaced.
 
A fusible link is... a fuse. It either conducts or it doesn't.

If your truck starts, the fusible links are functional. They may have increased resistance, but they are probably not your main problem.

"started it and battery and brake light and buzzered also."

The above would be more useful if expressed in English. I'm going to take a shot and guess you are saying that the battery light stayed on after starting? That means your charging system as a whole is failing to deliver 12v. Could be a bad alternator. Could be a bad battery. Could be a bad ground.

Solving electrical problems is a process of elimination. The first step is always to confirm the primary connections are clean and secure -- alternator to battery positive, battery positive to fusebox, battery positive to starter, battery negative to body/frame, block to frame ground, body to frame ground...

Then confirm the alternator is outputting at least 13.5v at the primary lug. Anything less suggests a weak alternator and/or failing voltage regulator.

If the reading on the alternator is good, confirm that the battery is getting the full output of the alternator. As wires age, resistance increases. It's not unusual to find that the alternator is putting out 14v, but the battery is only seeing 12v. That will not keep it charged.

The battery should be load tested. If it reads below 9.6v under load, it's weak and likely needs to be replaced.

Equally great explanation!

Drove through White Salmon last summer with my son doing the Washington Backcountry Discovery Route. Shoulda stopped by...
 
Fuseable link might work but not bring enough volts through, check both sides of it with a volt meter. Mike
 
fxxx them off and put some water proof wedge fuse holdes in their place with some 20A fuses. they are the biggest pain in the ass, why toyota didnt just use the same style fuses as the ones in the fuse box is beyond me. then go and fuse a large guage wire (based on the amperage of you alt) on both ends and run it from your alternator + to the battery + then report back :cheers:
 
next i will clean wires from alternator. when i rev up the engine the volts go up. and the battery and brake light, buzzed goes away. rpm goes down they come back on.
Is the belt slipping?

No real difference between slow-blo fuses (be sure to get that type if you opt for fuses) and fusible links. On my CTD I put all of the fusible links all on a terminal strip and made spares that are screwed down on empty terminals.
 
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If your truck starts, the fusible links are functional. They may have increased resistance, but they are probably not your main problem.

Ummm not really. any one of the wires can be bad and the other work fine. (ie. truck starts, but no headlights, dash lights etc.)

Take a look at the wiring diagram to get a sense how Mr. T designed it. Its actually really simple and well engineered IMO.

To OP. the fusible link can be tested. unplug/jump circuit and measure voltage. If you get a drop, likely the link is bad or starting to go bad.

Contrary to what some may think, the link is not a "go - no/go" part. A fuse will pop, but a fusible link can burn up slowly/over time.

A quick diagnostic... grab wire and pull in each end, if soft. stretchy its likely bad.

Buy two when you order them that way one stays in the glovebox as spare.
 
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My MG also went south at the 12 month point. When it went bad it cooked the alt fusible link. The link still conducted electricity, but not at full power, having close to a 2 volt drop.

I did get a new alt, after 7 months of calls, emails. What finally worked was having the Ebay seller put the pressure on. I will NEVER buy another MG anything!

And as far as fusible links go, I went to Kragen auto parts, and bought the rolls of link, and made my own.

:bounce:
Fusible link.-1.jpg
 
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Fuseable links are not one thing, the link(s) is plural, there are three independent wires that serve different circuits. It is quite common in any vehicle type that the link that serves the line between the battery and the alternator starts to give you problems when the alternators are upgraded to higher output. It's perfectly possible that you are having an issue with the links and they do not always just blow, they can slowly wear out from slightly excessive heat combined with vibration.

I like to separate the circuits and run a new 8 gauge cable from the alt to battery with an appropriate sized mega-fuse in line. The other circuits I then run right off the battery and use waterproof blade style fuse holders to mimic what was originally done with the links.
You need heavy duty fuse holders though (not the cheap s*** with 18ga wires) since one of the circuits can easily see 30amps of draw and the other two can see mid 20s on a regular basis.


IMG_7524.jpg
 
Hey Kevin, any chance you can do a small write-up on that little build? I plan on doing an upgrade to Fourrunner's cable kit in the near future and figure I might as well do this while I am at it since the lines going to my fusible links look to be pretty corroded and could probably use to be replaced/clean-up.
 

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