My Ammeter Bypass/Voltmeter Solution

[El Toro J10]

Well I guess I shouldn't really call it MY solution. I have performed quite a bit of research and am going to complete the ammeter bypass/voltmeter addition in my J10. After reading through a lot of posts and studying up on other sites, here is what I have come up with.

Ammeter Bypass
I just upgraded to the CS144 so I have some urgency in completing at least the bypass. I have opted for an under the hood bypass since I don?t feel I will have eliminated much (if any risk) just switching the connectors to one post on the ammeter with that juice still running through ~15 feet of 20 year old wire, into harness and through the cab. I found an excellent under the hood bypass by Araknid75, found here:

http://www.ifsja.org/forums/vb/showthread.php?t=105253


And here is my art work of how I picture it. I am going to use 6 ga wire since I am running the CS144. Sound good?



That should take care of the fire risk from the ammeter.

Voltmeter Installation
I really want to maintain the OEM look on my instument panel. I am going to follow the procedure as shown by Ted_Z in the following thread with only one modification:

http://www.ifsja.org/forums/vb/showthread.php?t=17510

As I read through this he says he plans on just using the old wires to the voltmeter. As mentioned previously, this isn?t enough security for my taste. I am going to use an in dash accessory wire (radio power most likely) and tie into that. I already check the voltmeter part number he referenced and it is still available.

Please let me know what you think.

[caionneach]

Ammeter wires

I did the ammeter bypass and the voltmeter in-dash installation you referenced. I also used the two ammeter wires hooked to the positive post on the voltmeter install just like in the write up, and it works just fine.

I agree that it is not ideal, but ideal would be all new wires or a new wiring harness for the FSJ.

Mine works, but the voltmeter is on all the time with this setup.

Not a big deal as it is not a big drain on the battery, as per the write up. However, key-on power is still the way to go. I need to take those two ammeter wires out of the circuit, so to speak, but I'm not sure how to proceed.

I could shorten them and splice them together to complete the circuit, like they do now fastened to the same post on the voltmeter. Ideally I would take them out altogether since they are older wires, but that might mean compromising the "BIG SPLICE" also located under the dash.

In short, I need someone smarter than me and way more familiar with the under dash wiring to produce a write-up of what to do in order to eliminate these old ammeter wires.

[710 Burner]

Just curious...you put on an alternator with a max rated output of 140 amperes, running the output through a 100 amp breaker. I'm guessing you do not expect to reach the max rated output of the alternator?

[El Toro J10]

That is correct. If I ever top 100 amps in my rig as currently configured something will be very wrong. I got a good deal on the CS144 so that is why I chose it. None of the near-stock alternators I saw would give me much better than I already had. If I ever need more flow I can easily upgrade the breaker.

The alternator won't kick out more than 100 amps unless I am asking for them right? Also, the write up recomended the breaker and it seemed to be a good safety mechanism. Even though a 150 amp breaker would catch it in the event of a problem, wouldn't that be too much juice? Other thoughts?

[lost1]

Well, that sounds reasonable to me. Unless you're asking for that draw with a lot of heavy-duty electrical accessories, the only other thing that'd make the alt put out that much amperage would be a malfunction of the alt, and that alone could start a long list of nasty problems.

[El_Diablo]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320414876487&rvr_id=&crlp=1_263602_263622&UA=WVF%3F&GUID=dd6139c01220a09c1216cc86ffe6b384&itemid=320414876487&ff4=263602_263622

http://www.opentip.com/Electronics-Computers/Wireless-Solutions-Amp-Circuit-Breaker-p-1131144.html

either should work, the later of the two being a well known product

[El Toro J10]

Thanks El_Diablo! The help is much appreciated. I may order one tomorrow.

[djongeward]

Autozone has those or similar in 100 and 150 amp at close to same price. Marine grade. Folks use them with high output audio amps.

[Tatsadasayago]

One nice aspect to the 100A breaker is that should the CS go full field, the breaker will pop before the alternator can self destruct or murder too many other things.

Considering that all the exterior/engine bay/interior accessories ON at once (Starter not included) would likely cause a 45-55 amp draw, I would think that only in the event of a dead short would the breaker pop.
I've never performed an energy budget on an FSJ....so perhaps my Jeep will be the test mule for that.

I am going the cs route soon and I appreciate you sharing this solution El D!

[El_Diablo]

Autozone has those or similar in 100 and 150 amp at close to same price. Marine grade. Folks use them with high output audio amps.

they do have both, but the main problem is that neither is the one you actually need....


the big reason for the 140amp is what if down the road you add some lights, you have an electric fan and it kicks on (80-90amps), you have your heater on (probably around 15 amps im guessing) and you've already maxed out that breaker.... now what if its at night (headlights) and its raining (wipers)?

you're alternator will try its hardest to replace the energy being used and that may bring you close to the peak.... if you choose replace the electric fan with a winch, same deal....

[710 Burner]

I like it.
Like you said, "as configured"...I don't think you would ever reach 100. It might be possible if you have to crank on the starter a long time and replenish the battery, but not very likely even then. You would never trip a 150 because the alternator is not rated for it, and if the alternator is not capable of putting out 140 (say, it peaks at 136A) you may never trip a 140 either.

[El Toro J10]

I appreciate the input from everyone. As always, very constructive. The forum has mentored me through my work thus far.

[El Toro J10]

One more question. In the ammeter bypass how to it says to disconnect the wire from the "batt" terminal on the back of the alternator. This is the wire that runs into the cab to the ammeter. Don't I also need to disconnect the original wire from the "batt" terminal on the solenoid since that also runs to the cab? Yeah, its not connected for a full circuit but if it chaffs and shorts somewhere in between then I am still up the creek.

Thoughts?

[El_Diablo]

I like it.
Like you said, "as configured"...I don't think you would ever reach 100. It might be possible if you have to crank on the starter a long time and replenish the battery, but not very likely even then. You would never trip a 150 because the alternator is not rated for it, and if the alternator is not capable of putting out 140 (say, it peaks at 136A) you may never trip a 140 either.

then run a 135 if that makes you feel better

[710 Burner]

One more question. In the ammeter bypass how to it says to disconnect the wire from the "batt" terminal on the back of the alternator. This is the wire that runs into the cab to the ammeter. Don't I also need to disconnect the original wire from the "batt" terminal on the solenoid since that also runs to the cab? Yeah, its not connected for a full circuit but if it chaffs and shorts somewhere in between then I am still up the creek.

Thoughts?

You need the either the battery wire connected or the alternator wire you removed connected to a battery source for the dash and ign power. The battery wire already has a fusible link, the alternator wire does not.