You also forgot to paste the check for $2000!!! So much good stuff out there, start collecting and by the time we die we'll have it all covered....hopefully our kids like wrenching.
Help chasing current draw (1 Viewer)
- Thread starter workingdog
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My only experience with a replacement alternator was the purchase of a reman’d FJ60 alternator from Georg (@orangefj45)... good price, great alternator.
Edit: BTW one of my favorite mods is the hidden battery cutoff switch... I make a practice of turning the battery off every time I park it... saves the battery... and potientially the truck.
Depending on what you mean by "high output alternator", you may have to upgrade the wire leaving the alternator, connecting to the battery. The standard ammeter may have to be bypassed, as well.
I know 2K is quite large but think about it. You can use a small clamp, connect to one wire, and hook to scope,, and see result. Those other clamps you have to maneuver the whole assembly and even if the clamp head is somewhat small, the body of the meter may be an issue. I would only invest in that if I could recover some cash somewhere along the line.
workingdog
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- Thread starter
- #25
It's a 200 amp alternator. The ammeter is gone. I am going to upgrade the wire.
1911
chupacabra
I have a 200-amp alternator in mine also. Here are the reasons I run one, in no particular order:
1. My Warn 8274 Winch pulls 525 amps at start-up under load, and more than 100 (200?) amps while running.
2. I have a lot of extra equipment in my 40; ham radios, cb, ARB fridge, stereo amp, GPS, and upgraded headlights & harness.
3. I didn't like it when my lights would dim at idle with the stock alternator; now I don't have that problem.
4. I'd rather have excess capacity and not need it, rather than overworking a marginally-suited alternator.
I would second the alternator.
However, several times I have found that it was a bad ground. Diagnosing by substituting a thick jumper cable from negative terminal to engine may show if having a clean ground will have a "positive" effect.
Specifically the ground that is down under the driver's side and A/C grounding bolt. Follow the negative terminal to below the fuse box and below the body attachment. Either clean / polish the metal with a wire brush or order new components; they are less than $15 total. Solved my draining battery problem.
When you are checking the current draw are you disconnecting the ground wire and measuring between negative terminal and ground? It's one way of avoiding wiping out your meters. Sometimes it is even recommended to put in a 1K resistor in series.
However, several times I have found that it was a bad ground. Diagnosing by substituting a thick jumper cable from negative terminal to engine may show if having a clean ground will have a "positive" effect.
Specifically the ground that is down under the driver's side and A/C grounding bolt. Follow the negative terminal to below the fuse box and below the body attachment. Either clean / polish the metal with a wire brush or order new components; they are less than $15 total. Solved my draining battery problem.
When you are checking the current draw are you disconnecting the ground wire and measuring between negative terminal and ground? It's one way of avoiding wiping out your meters. Sometimes it is even recommended to put in a 1K resistor in series.
workingdog
GOLD Star
- Thread starter
- #29
I ended up checking the diode using my meter. I think that’s pretty definitive. I’ve got the same winch as mentioned and a double arb compressor - and stuff
I certainly understand the need for more power with upgrades BUT most people who do this fail to re-engineer the wire sizes and the proper distribution for the new available power. I have seen quite a few who have done this and have had "electrical issues" and fail to figure out why.
workingdog
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- Thread starter
- #32
YES! Current draw is less than 10 ma with the alternator disconnected and the diode test on the alternator failed - which I thin is totally definitive.
You don't have to upgrade all the wiring because of you have a larger alternator. The additional current will only flow to where it is needed. And you only need to upgrade along the paths that the current can flow. The demand to the cab has actually hasn't changed much. I've added radios and things but moved the headlights and driving lights out of the cab. Most of the increased amperage is going to the winch and ARB compressor that connect directly to the battery.
You don't have to upgrade all the wiring because of you have a larger alternator. The additional current will only flow to where it is needed. And you only need to upgrade along the paths that the current can flow. The demand to the cab has actually hasn't changed much. I've added radios and things but moved the headlights and driving lights out of the cab. Most of the increased amperage is going to the winch and ARB compressor that connect directly to the battery.
workingdog
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- Thread starter
- #33
The new Powermaster alternator arrived. It was interesting to see test results on a tag
Idle: 151 amps
Cruise: 195 amps
Top end: 221 amps
Volt regulator set at 14.8
Idle: 151 amps
Cruise: 195 amps
Top end: 221 amps
Volt regulator set at 14.8
workingdog
GOLD Star
- Thread starter
- #34
"200 amp is the service to my house. My FJ40 has 30 amp alternator. Why so large ?"
The 200 amp service to your house is at 240 volts. There's a huge difference. The stock alternator on the 6.0 liter vortec in my FJ40 is 105 amps. I don't think any modern car has anything close to a 30 amps alternator. 200 amps for all the stuff that's on my 40 isn't that out of line - although I probably could have gotten by with 145.
The 200 amp service to your house is at 240 volts. There's a huge difference. The stock alternator on the 6.0 liter vortec in my FJ40 is 105 amps. I don't think any modern car has anything close to a 30 amps alternator. 200 amps for all the stuff that's on my 40 isn't that out of line - although I probably could have gotten by with 145.
I know the difference between house current and DC current. Also, I have a 1969 FJ40 and the only thing electrical are the lights , horn, and an early winch. The amp gauge is pegged at 30 amps. I do not know what amperage the stock alternator is but my bet it is no where near 100 amps. ( A 1969 is not a modern car.)
When I mentioned aftermarket add ons people do , I know any electrical item will only draw what it needs to run. The issue I have in design is protection as in, "what if they fail" ? You certainly just went through this. A diode draws very little NORMALLY. Obviously a failure mode happened to you and the diode was drawing more current than expected. This is why fusible links exist , if to much draw for aany reason happens, they will open protecting the wiring.
Sounds like you are doing well and I will add a good link concerning running a high output alternator. It kind of shows how much current items will draw.
Alt Text: 5 Things You Should Know Before Using a High-Output Alternator
Also , blue sea systems, big outfit for boat and car wiring and fusing, D.C. , has some info on wire size if you are interested. I just finished wiring a boat with dual high output alternators and really worked hard on the protection side of things.
Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems
