Good Amperage?

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What should the correct amperage output be for a 1995 fj80? I just had the battery tested (it was bad) and replaced. I also had the altenator tested and the tech said that the voltage was 14.69, the diodes where good, but that the amps were low - 39 or so. What should they be, the tech said around 70 or 80.
 
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Search on this topic (i.e. alternator, amps, voltage, etc.). There have been a few threads recently discussing this topic. Also, it has been suggested by several Mudders that the wires from the alternator should be replaced with heavier gauge wires in order to capture the full performance of the alternator. I have not done so, but intend to as this would be a low budget mod to improve the 80s electrical performance.

In regards to the techs idea of output, I think he is incorrect in the output of the OEM alternator (depending on what RPM range he is referring to), but I'm sure someone will chime in with the factory specs on the OEM alternator's output.
 
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What should the correct amperage output be for a 1995 fj80? I just had the battery tested (it was bad) and replaced. I also had the altenator tested and the tech said that the voltage was 14.69, the diodes where good, but that the amps were low - 39 or so. What should they be, the tech said around 70 or 80.

Depends how much load is being applied. In other words 39 amps at 14.7 volts is perfectly acceptable, provided the alternator is spinning quickly enough and the load being applied is about 40 amps. If you apply an 80 amp load, you would expect to see the voltage decrease, so if you get 14 volts at 80 amps, that would be acceptable as well.
 
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Also, it has been suggested by several Mudders that the wires from the alternator should be replaced with heavier gauge wires in order to capture the full performance of the alternator. I have not done so, but intend to as this would be a low budget mod to improve the 80s electrical performance.

Once you replace all the wires including the ones who feed the ignition switcher, you will notice your windows rolling up faster, less flickering of the instrument panel illumination, better perfomance of your headlamps, etc.
 
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Once you replace all the wires including the ones who feed the ignition switcher, you will notice your windows rolling up faster, less flickering of the instrument panel illumination, better perfomance of your headlamps, etc.

Robmir, so I'm clear, what are "all the wires" that you replaced? I'm planning on doing this soon, and don't want to miss anything.
Thanks,
Nick
 
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Robmir, so I'm clear, what are "all the wires" that you replaced? I'm planning on doing this soon, and don't want to miss anything.
Thanks,
Nick

As I recall the white wires: one that goes from the alternator out to the fusible link close to the positive battery post (as to charge the battery) and the other white wire which go to the fusebox under the dashboard (This white wire supply constant high current to some accesories inside the vehicle when they are on). Also the black with blue strip wire which came from the fusible link box close to the battery to feed the ignition switcher, this wire will feed all the circuits that are on in the accesory position which of course will be added to the ones that are on in the ignition position.

It would be smart to check how are the contacts of the female and male connector which hook the ignition switcher. We had to replace the ignition switcher on a couple of friends 80's because with time the contacts inside overheat a bit and loose conductivity. Unfortunately this is something you can't see just from looking at it. The technical way is to measure with a precise multimeter the voltage on this black with blue strip wire versus the switcher ouput wires when the vehicle is on with the air condition at it's max, wiper at it's max speed and rolling up the window, if there is a serious voltage drop then the ignition switcher contacts are pitted or overheated.

You should also increase the size of the wire from the negative battery post to the body frame.

If you are willing to do it then take all your time, this should not be a rushing job because it requires a lot of wire harness disassembling, replacing the wires and nicely taping the harness again.

But you could go for the easy way which is adding a new thinner wire (a #10 stranded will be fine) taped or with tie wraps to the oem harness which you will hook in parallel with the original wire at both ends (soldering it of course). With this setup you are increasing a lot the current handling without a major installation hassle.
 
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