[69][4K] Odyssey AGM Battery and GM DIODE Mod for higher Voltage for Proper Charge
- Thread starter youngwas
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STX4Runner
New member
I have the same battery and bought the GM diode last year. No matter which way I install it I have the battery light on the dash illuminated and only 13.6 volts on the voltmeter. With the stock 7.5 amp fuse I have no battery light and 13.9 volts. I hook up a NOCO charger/maintainer every few weeks and it always shows a healthy battery. Any idea why the diode isn't working?
youngwas
New member
I think you should try a new diode. Yours might be bad. It worked right away. No engine light and the voltage is 14.5v. It’s only $7. Try it.
03_4x4Runner
Senior Member
Do we need another thread on this subject? Beating a dead horse.
"Voltage Booster" for 31M AGM Battery
Raising the Alternator's voltage to properly feed your AGM Battery!
AGM battery charge controller
"Voltage Booster" for 31M AGM Battery
"Voltage Booster" for 31M AGM Battery
"Voltage Booster" for 31M AGM Battery
Raising the Alternator's voltage to properly feed your AGM Battery!
AGM battery charge controller
"Voltage Booster" for 31M AGM Battery
"Voltage Booster" for 31M AGM Battery
Cool, was waiting for the internet police to show up. Wasn't disappointed.
STX4Runner
New member
Was gonna say the same thing. This thread is fine, the OP even posted a couple of videos to help out.
No one tell him he posted the same thread twice (edit: three times!) in his "yOu ShOuLd hAvE sEaRcHeD fIrSt" reply.
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[69] in the thread title for the 69th thread on this subject
mrblah
Senior Member
fourrunnerbill
Member
If you have a multimeter with a diode check feature you can check it that way.
Or, with just an ohm meter the diode should have low resistance when the leads are in one way and if you swap the leads the resistance should be high.
Or, with just an ohm meter the diode should have low resistance when the leads are in one way and if you swap the leads the resistance should be high.
T4R_Canuck
Member
I've got this exact setup and it has been working flawlessly since installing it early in the spring. I had already installed an on board battery maintainer to top up my battery occasionally but haven't had to use it since installing the GM Diode as I do enough highway driving to keep my Odyssey battery fully charged now.
THIS^^^
Mine is similar, but have a Redarc BCDC charger on the AGM auxiliary battery.
With the diode, both stay charged fully. Battery monitors show 12.6 on the Lead acid main battery and 13.1 on the Auxiliary once the engine has been running for a few minutes.
Cold start shows 14.1 on the lead acid and 14.5 on the AGM. The BCDC shuts down the AGM charge to a trickle after a minute or so. Lead acid takes a few more minutes to rebuild after the engine start.
I use an onboard NOCO 5X2 charger as a backup/maintainer.
Just put mine in.
There is a mistake in the video.
He puts the diode in the correct place, but then later misidentifies which slot it went intosaying it is the AM1. It does not go into the AM1 slot, it goes into the one that is marked"ALT-S", which I guess makes sense.
All in all a good video, the biggest problem I had was getting the fusebox open. I found another video somewhere that mentioned how to do it.
I trimmed the diode mostly with big ass toenail clippers, then used the file on the last little nubby.
:whipping2
Car is still running . . .
There is a mistake in the video.
He puts the diode in the correct place, but then later misidentifies which slot it went intosaying it is the AM1. It does not go into the AM1 slot, it goes into the one that is marked"ALT-S", which I guess makes sense.
All in all a good video, the biggest problem I had was getting the fusebox open. I found another video somewhere that mentioned how to do it.
I trimmed the diode mostly with big ass toenail clippers, then used the file on the last little nubby.
:whipping2
Car is still running . . .
Installed the Odyssey Battery and GM diode on my 2021 TRD Pro. The fuse box on my truck is different from anything I saw on videos so I am hopefully posting some pics of the new fuse box and diode position. The arrow for the diode now points towards the front of the car. I am getting 14.6 volts with the engine on. All good! Best I can do is add a link to the three photos. The fuse I replaced is the same 7.5 amp as in the videos.
Toyota fuses - Google Photos
Toyota fuses - Google Photos
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octanejunkie
Elite Member
What is the value of adding a diode fuse - does it even do anything?
Most seem to be using the Arclight Voltage Booster...
Triple State Voltage Booster - 5th Gen 4Runner — ArcLightLEDs
Most seem to be using the Arclight Voltage Booster...
Triple State Voltage Booster - 5th Gen 4Runner — ArcLightLEDs
T4R_Canuck
Member
My unscientific understanding is that it provides resistance on the circuit that makes your smart alternator increase its voltage output, thus giving you a high enough voltage output to properly charge an AGM battery. It costs $5-$7 and does the exact same thing as the $100 arc light option, but without the little switch to change between stock output and boost. To go back to stock output when using the diode, you'd just put the stock fuse back in, which would only be necessary if you decided to remove the AGM battery for a stock wet lead acid battery again.
Ripper238
Senior Member
Arclight is just a better more flexible option since its fused and has the 3 settings. I use over boost when i am not driving much/long and in winter, summer I use regular boost and if I need to use a standard battery (emergency) I can switch to standard charging.
