Alternator relocation and wiring - What gauge wire? (1 Viewer)

[SouthBostonFJ40]

I'm in the process of moving my alternator to the passenger side and I need to extend my wiring. What gauge wire was used originally? It looks like 18 awg. Also, should I just splice in at the original location or is there another way?

 

[bgray]

When I did the same thing on my 11/72 FJ40, I seem to recall that if you unwind the wiring jacket back to the firewall, you have enough slack to reroute it to the new location (or get w/in a foot or so). Others may know the exact gauge if you end up having to extend it.

 

[Cruiserdrew]

Do you have the 84 alternator as listed for the 2F in your sig line?

If it's the original 1971 Fj40 alternator making 36 or 40 amps the B wire needs to be at least 12 ga.

If you've upgraded to the 84 alternator that came with your 84 2F, it can make 60 amps and you should upgrade to 10 or 8.

The other wires don't carry much load, so the sizing is not super critical, and 18 will be fine.

See this: American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire strength

 

[SouthBostonFJ40]

Do you have the 84 alternator as listed for the 2F in your sig line?

If it's the original 1971 Fj40 alternator making 36 or 40 amps the B wire needs to be at least 12 ga.

If you've upgraded to the 84 alternator that came with your 84 2F, it can make 60 amps and you should upgrade to 10 or 8.

The other wires don't carry much load, so the sizing is not super critical, and 18 will be fine.

See this: American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire strength

When I first got my truck, the guy I bought it from told me it had a 1975 2F in it. I knew very little about FJ40's. The alternator went almost immediately after I bought it so I went to the dealer, told them I had a 71 FJ40 and they sold me a new one. So I assume it's not the right one.
Here's a picture of it.

Here it is with a broken wire a few years ago.

 

[Cruiserdrew]

It's not a later alternator with the internal regulator. Since that's the case, it makes 40 amps or less and you will be OK with 12 ga wire.

I have an alternator that should fit better in the bracket than that one if you need it. It's off a 76 and makes 40 amps. It was originally installed on the PS and so the terminals should be in a better position for you. You can have it for shipping. Let me know.

When I put the 85 2F in my FJ40, I used the later alternator to upgrade my available power to 60 amps and upgraded the wire to 10ga.

 

[SouthBostonFJ40]

It's not a later alternator with the internal regulator. Since that's the case, it makes 40 amps or less and you will be OK with 12 ga wire.

I have an alternator that should fit better in the bracket than that one if you need it. It's off a 76 and makes 40 amps. It was originally installed on the PS and so the terminals should be in a better position for you. You can have it for shipping. Let me know.

When I put the 85 2F in my FJ40, I used the later alternator to upgrade my available power to 60 amps and upgraded the wire to 10ga.

Thanks for the offer Drew...but do you think I should also upgrade to the later alternator? I have a winch, CB, aux. lights and a marine amp.

 

[Cruiserdrew]

Thanks for the offer Drew...but do you think I should also upgrade to the later alternator? I have a winch, CB, aux. lights and a marine amp.

More power is always good, and you could get away from the points based voltage regulator, so it would be a win-win.

I don't know what a marine amp is, but the way to look at this is to look at your max amp draw without the winch, ie lights, ignition, stereo cranked, heater blower and wipers on and if you don't exceed 40 amps you should be fine. The aux lights and the stereo though, to me, suggest that more power would be good.

What happens to your charging voltage when everything is on (forget the winch, that runs off the battery only for all practical purposes)? That would be the poor man's way to figure this out. If charging voltage drops below say 13.5 volts at 1500rpm, you need more alternator power.

Is your dash ammeter hooked up and working?

 

[SouthBostonFJ40]

More power is always good, and you could get away from the points based voltage regulator, so it would be a win-win.

I don't know what a marine amp is, but the way to look at this is to look at your max amp draw without the winch, ie lights, ignition, stereo cranked, heater blower and wipers on and if you don't exceed 40 amps you should be fine. The aux lights and the stereo though, to me, suggest that more power would be good.

What happens to your charging voltage when everything is on (forget the winch, that runs off the battery only for all practical purposes)? That would be the poor man's way to figure this out. If charging voltage drops below say 13.5 volts at 1500rpm, you need more alternator power.

Is your dash ammeter hooked up and working?

A marine amp is what powers my iPod stereo. My dash ampmeter hops back and forth like a ping pong ball so it's useless.

How hard is the swap to do?

 

[SouthBostonFJ40]

I just found this...

Which part number should I buy?

 

[Cruiserdrew]

A marine amp is what powers my iPod stereo. My dash ampmeter hops back and forth like a ping pong ball so it's useless.

How hard is the swap to do?

The ammeter is extremely useful because it tells you how the current is flowing in your cruiser. It sits inline between the battery and the alternator. Most of the loads in stock form come off the alternator side of the ammeter. So if the ammeter is +, there is enough current to power all your loads and current is flowing into (ie charging) your battery. If (-) then it's flowing away from, and discharging, the battery. IT's that simple. So in stock form, assuming full charge in the battery, a negative reading means your (-) side loads are exceeding your charging capacity and power is flowing out of the battery.

In many ways an ammeter is better than a voltage meter as you know immediately if you are at risk of discharging your battery. Voltage changes much more slowly, which is why cars with a volt meter also have an idiot light. My "ping-pong" effect went away with the internally regulated alternator. I think the points opening and closing in the stock voltage regulator cause the bouncing effect.


The swap itself is trivial. It bolts up to your bracket, but you will need some minor wiring changes and an FJ60 alternator plug. If you wire the output B to the (-) side of the ammeter, the ammeter will work like stock. You do need a 12v source for the exciter wire.

 

[SouthBostonFJ40]

The swap itself is trivial. It bolts up to your bracket, but you will need some minor wiring changes and an FJ60 alternator plug. If you wire the output B to the (-) side of the ammeter, the ammeter will work like stock. You do need a 12v source for the exciter wire.

Thanks Drew! Any idea where to get an FJ60 alternator plug? Also, which alternator should I get?

 

[Cruiserdrew]

Thanks Drew! Any idea where to get an FJ60 alternator plug? Also, which alternator should I get?

I got a FJ60 alternator plug from my local auto electrical place. Easiest might be from someone parting a 60.

If you want to go the 60 alternator route 8008-8708 looks like the time frame. I think in the US they were all the same and had IC regulators. Just remember you will need to mod your electrics a bit.

You might also consider a GM alternator which will be cheaper and produce more power. I wanted to stay with Toyota but you may feel differently. The 'One Wire" GM alternators looks very easy to install since they self excite and the One wire goes directly to the battery. That will render your ammeter useless, though.

Read through the threads on alternator swaps because you have a lot of choices.

 

[Coolerman]

Be aware that if you swap to a higher than 30 amp alternator you will need to swap your current 30 amp, Amp Meter, to the later 50 amp version. If you don't you will fry it the first time you pull more than 30 amps. It's an easy swap.
I would also add a fusible link at this time to protect the B+ wiring in the harness.

 

[SouthBostonFJ40]

Be aware that if you swap to a higher than 30 amp alternator you will need to swap your current 30 amp, Amp Meter, to the later 50 amp version. If you don't you will fry it the first time you pull more than 30 amps. It's an easy swap.
I would also add a fusible link at this time to protect the B+ wiring in the harness.

All the ones I'm seeing are 24v, like this one...

http://www.toyotapartszone.com/oem/toyota~ammeter~assy~83610-60023.html

Will it work?

 

[bj40green]

Be aware that if you swap to a higher than 30 amp alternator you will need to swap your current 30 amp, Amp Meter, to the later 50 amp version. If you don't you will fry it the first time you pull more than 30 amps. It's an easy swap.
I would also add a fusible link at this time to protect the B+ wiring in the harness.

The 30 and 50 gauges are not interchangeable.
The 30 is a real AMP gauge. The full current runs through the gauge.
The 50 ('79 and later) is a shunt gauge with a 50:1 ratio. 50 Amps runs through the nest of fusible links and 1 Amp runs through the gauge.
If you replace the 30 for a 50 the 50 is toast when you turn the key because the ignition plus the cluster gauges are pulling a few amps and the 50 can handle only 1.

My advice is to run the stock wiring with extensions to an external 50Amp gauge under the dash.

Rudi

P.s. An AMP gauge is not 12V or 24V it measures AMPS no matter the voltage.

 

[DSRTRDR]

A marine amp is what powers my iPod stereo. My dash ampmeter hops back and forth like a ping pong ball so it's useless.

How hard is the swap to do?

the ping pong ball effect happens when you have a bad ground somewhere - dimmer switch is often to blame - in my experience, rear brake lights and blinkers most often contributed (bulb not properly seated, grounding bolt nut came loose, bulb blown) but the front blinkers can be to blame, too - a loose blinker switch rod (at the steering wheel side) and a loose connector at the parking brake can also do it

alternatively, the voltage regulator took a crap - I haven't had that happen yet, and my regulator seems to be original - I cleaned it up a few years ago

I find the ammeter quite useful and will figure out a way to keep it when I get the winch and second battery

 

[Coolerman]

Oooops! You are correct sir! I should have added you would need the wiring for the 50 amp gauge also which is a bit more complicated and doesn't really work well anyway.
I have a shunt block rated for 100amps that outputs 5 milli-volts for every amp through it. I use it when building harnesses to measure current flow for different circuits. See attached pic. One of these days I want to build a system that uses a cheap under dash mount volt meter and this shunt that could replace the amp meter in just these cases.

Also the OEM wire size for the B+ wire on the 71 was a bit larger than 10ga. I sell 8ga wire for the replacement. The other two wires to the alternator are 18ga.

I would follow the advice about unwrapping the harness as far as needed and moving the wires. It will be easier if you remove the harness from the truck and lay it out so you can do it right. I would also as already mentioned add a fusible link.

The 30 and 50 gauges are not interchangeable.
The 30 is a real AMP gauge. The full current runs through the gauge.
The 50 ('79 and later) is a shunt gauge with a 50:1 ratio. 50 Amps runs through the nest of fusible links and 1 Amp runs through the gauge.
If you replace the 30 for a 50 the 50 is toast when you turn the key because the ignition plus the cluster gauges are pulling a few amps and the 50 can handle only 1.

My advice is to run the stock wiring with extensions to an external 50Amp gauge under the dash.

Rudi

P.s. An AMP gauge is not 12V or 24V it measures AMPS no matter the voltage.

 

[Hugh Heifer]

Funny this is TTT. I am in the process of wiring in an FJ60 alternator into a 40 as well. I am going to run a volt meter instead of an amp meter and am going with all aftermarket gauges.

I forgot that I can remove the voltage regulator and have found some posts by Jim C to help me with that. I too am looking for a plug for the FJ60 alternator. I do not have the luxury of any type of auto electrical place nearby. Drew - do you have a brand or part number from the plug? I was thinking I could source it on the web if I can't find someone parting a 60.

 

[Coolerman]

Here is one source though they sure ar not cheap!
http://www.repairconnector.com/prod...Repair-Connector-2-Wire-Female-Terminals.html

 

[Cruiserdrew]

Funny this is TTT. I am in the process of wiring in an FJ60 alternator into a 40 as well. I am going to run a volt meter instead of an amp meter and am going with all aftermarket gauges.

I forgot that I can remove the voltage regulator and have found some posts by Jim C to help me with that. I too am looking for a plug for the FJ60 alternator. I do not have the luxury of any type of auto electrical place nearby. Drew - do you have a brand or part number from the plug? I was thinking I could source it on the web if I can't find someone parting a 60.

I see the Coolerman has come through with a great source--$9.99 does not seem too bad. If you like, I have a used plug you can have, but I'd recommend you use the new one. $9.99 in the scheme of Land Cruisers is not very much cash.

BTW-I used a whole bunch of Coolerman's parts to wire in the new harness, so even though it's an aftermarket harness, it works like stock with stock connectors. Highly recommended that you buy and use Coolerman's stuff. It has been so great to have all clean and new wiring, and modern fuses.

One other thing-I ran the wiring in stock configuration from the alternator B terminal to the (-) side of the ammeter and it has not hurt the ammeter yet. The bar in the ammeter that carries all the current looks like it can handle a lot more than 60 amps.