This is a great little mod. I bought the "add a fuse" and a diode for less than $10. It increased my cold-start voltage from 14.1 V to 14.7V. Should suit my Northstar well.
Alternator Voltage Booster (4 Viewers)
- Thread starter OregonLC
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Same. 14.2 to 14.7 volts and still have the fuse protection. Thanks folks, especially @AimCOtaco, for this little mod.
Last edited:
From 13.5V fully (warmed up) to 14.0V after the diode mod. Got mine from o’reilly’s -had to order it and wait and pick it up the next day.
ramangain
Clarksonian disciple
Fixed it for you. Gotta ensure those kyber crystal shards fuse correctly
Tapage
Club 4X4 Panamá
I've been running that same diode for a few thousand miles now in my '03 LX... seems to be working well! I do get voltage readings every now and then on my Ultragauge of like 15.1 volts, but it's only for a brief moment. (I have an alert setup to let me know if voltage goes above 15, which is how I'm seeing the voltage briefly hit that high)
Is that Diode also a fuse? I'm glad it's working but I'd want to be sure that:
A. The Diode can handle unexpected loads (I used a 6-10A diode I think based on the 7.5A stock fuse).
B. The diode would pop and fail open if it hit loads that would pop the factory 7.5A fuse.
Not saying this Littelfuse diode isn't the greatest solution yet found, just stating my thoughts.
Running a big diode inline with the 7.5A fuse I'm confidant is both safe and robust.
A. The Diode can handle unexpected loads (I used a 6-10A diode I think based on the 7.5A stock fuse).
B. The diode would pop and fail open if it hit loads that would pop the factory 7.5A fuse.
Not saying this Littelfuse diode isn't the greatest solution yet found, just stating my thoughts.
Running a big diode inline with the 7.5A fuse I'm confidant is both safe and robust.
I agree.... it might not allow much more than 7.5A to come through. I don't have the right equipment to test, but would be great if someone who did would see how many amps the diode will take before it pops.
A company called TE connectivity makes a handy little fuse holder that should make it easy to daisy chain this diode and a fuse together for pretty cheap, but the metal connectors that go inside the fuse holder are on a 17 week lead time.... It would also require a mini fuse shaped device with pigtails to connect into the fuse panel.
2x mini fuse holder https://www.te.com/content/dam/te-c...ion/global/TS-ICT-2PNSFH_Mini_Fuse_Holder.pdf
mini fuse adapter with pig-tails: Amazon product ASIN B07CTRNYR1
I tried to find something with the pig tails on aliexpress, but no luck. Also had no luck finding the same type of product on a digikey type of site.
Actual readings:
Yes, by its nature a diode will fail OPEN like a fuse when carrying current above it's rating... usually. It will fail CLOSED with over voltage... usually. From the pic by @OEMGUY0720 the over current rating for the Littelfuse diode is 1A, which is more than ample for the sense line. The standard fuse rating of 7.5 does not reflect the current actually flowing through that wire, which under normal conditions is less than 10mA (<0.010 A). Instead, the 7.5 is just more of a standard value fuse and is ample to protect the wire from burning if somehow shorted to chassis ground.
If you want to test that this diode fails like a fuse, then buy an extra one and replace the fog light fuse (or some other switched circuit expected to pull >1A or >14 watts) with the diode. Switch on the lights and you might see a the lights come on very briefly. Flip the diode and look for brief light. At this point the diode is likely dead OPEN circuit.
Tapage
Club 4X4 Panamá
I had to trim the casing to fit inside the S. Alt fuse bank. I little nerve wrecking, but worked. If you insert the fuse the wrong way the battery CEL will display on the dash
It should be noted that this diode should not be used for a standard flooded battery if all systems are working properly. 13.6V from the alternator is optimal for charging with a tick lower for storage. Pumping a flooded continuously at >14v will cause too much gassing and damage the battery. >14v should only be present for equalization.
Any recommendation for what diode to use for this? I'm on Amazon shopping and the 6A diodes have different voltage ratings? Which one is best? And since I am asking questions, which diode voltage is best?
It would be great if someone has a reasoned answer for an electrical noob like myself
It would be great if someone has a reasoned answer for an electrical noob like myself
Bump on where I can source this diode to maintain the 7.5A fuse
If you’re here in North America you can get it from O’Reilly’s in-store or their online store. Check out my post above post #63 and #66.
Haha thanks, I am in America. I am just looking for the other option where I can keep the fuse as well. Has the solution from O'Reilly's been reliable for you?
A more expensive alternative, that requires some patience, in waiting for deferred gratification (read as they’re slow to ship):
Toyota - LC 100 | HKB Electronics
The Alternator Voltage Booster was the first of its type on the market and is the only unit available that was has been purpose built for alternator voltage boosting.
www.hkbelect.com
I don’t know if it is any better than the domestic O’Reilly’s option, at 4.5-5x the price, but it does seem to work, and allegedly acts as a fuse too.
I guess the other option might be to use a 7.5a fuse in series with the diode.
