im not sure why your car has such a low voltage at idle. ive got a marine deep cycle yellow top optima in my car, but even before the optima my car got 13.5 volts at idle. even with my 2,000 watt amp pumping my 12" subwoofers at full tilt with the HID headlights on it only drops to 13.0. i would check your grounding points everywhere.


one thing that might be worth looking at is the battery. my old optima dropped a couple cells causing the voltage to drop all the way to 10.5 volts at times.

Jason I know the ALT that is in that car is crapola. Just having the fan on high with your foot on the brake,radio on, daytime running lights on, it droops to 12.5 pretty quick while stopped and counts backwards if u stay stopped with all the extra wattage from the increased tail brake bulbs back there.. If u step on the gas it jumps back up immediately to 14.3v+ and you can hear the fan pick up a bit with the extra voltage.
The Odyssey battery when new loadtested at 1319 CCA about 17 months ago. That being said because of the lower state of charge from this crap alt, I will manually charge the Odyssey before install, to ensure it gets some correct power back in there. I am well aware that not the greatest amount of power at times has been reaching the battery, however I am sure that after next week with the new high output ALT and new wiring (which includes a new larger ground wire to body) that all will be well again.
Then I will re test the Odyssey battery to see how it is doing under a load test again.

Today I installed The new wiring using the Old Alternator to see how it will work.

I also installed a thicker ground wire to inner fender.

I am getting about a half a volt more now with this wiring.
Had about 13v loaded going in with old alt. Next is to install the new alt...
I guess I will also have to do some re-programming as I had the battery disconnected for a while. I noticed that when I go into drive all the doors lock now and when I go into park they all open..ha..never seen that before! I guess it will be a re-learn to for transmission etc as I cleared the computer..

Thick wiring ooks good, can't wait to see it with the new alternator in there!

The doors doing that should be a normal safety feature, whenever I go from park to drive the doors always lock, I can't remember if they unlock once I go back into park though, I want to say they do, but I'll have to see the next time I am in the car.

Ok without further a due.. Here it is installed!

Had to remove the bracket 3 different sized bolts, luckily with access to air tool.
Took about 15 to get old one off and 10 min to re-install, and then another 10min to get the PITA serpentine belt aligned to bottom pulley. One holds tensioner off, while person2 crawls under car to get that sucker back into the groves properly!! Good thing I did this in the early am outside cause the sun is hot..need a good drink now to celebrate & cool off!

Reports from Snap on at idle (only photo I took) too busy doing other stuff.

It works but....
It tested up loaded max @ 152 amps output..that is good...
BUT..I seem to have less voltage reading inside car even though I know the Digital voltage readings inside car are off. by .7 volt to 1 volt..Will re-test it in a few days using the snap on machine and really go though it with more pics.
My feeling is yes I have way more amps but not as much voltage as the stock ALT... wonder why that is?
Some formula may explain that...wattage etc stuff.

amps are what your alt puts out and what your devices use. well technically they consume power which is amps times volts. so same volts times more amps equals more power to feed your devices. you wouldnt want more volts that burns out power supplies in devices and bulbs.

Quality Power replied : The higher the amperage the lower the voltage.
They wanted to know what the amperage input was at what voltage.
I replied look at the photo I attached from Snap on Machine. 20 amps at 13.6 Volts will see what they say in next reply.
Further testing to come tonight to see if at idle I got more or less volts and what is going on.

It'* summer time. Get that darn cover off!!

Quoted for truth!
I have not put mine back on since doing the UIM/LIM, come to think of it I still need to put my splash guard back underneath.
I may put it back in the winter though, I am sure the rodent I have yet to be able to catch would enjoy another hiding spot.

I can see that with the cover off the engine etc might cool better.

But I thought it served as a BLAST shield for when your UIM'* Fail ~