Whats Up Honda-Tech

Well i have ran into an annoying problem i have a 2001 prelude and the battery will not charger at idle it will actually drain and then die....lets start from the beginning...

i relocated the battery to the trunk...
-Optima batter in the trunk
-0 guague wire from trunk to engine bay
-0 guague to a distribution block
-4 guague out of the distrubution block into the fuse box
-170 high output altenator
-aem pully on the alter
-MSD wires ran directly to battery as instructed

everything seems to be wired right car drains at idle but when driving it charges at 13 someone told me the edc on the fuse box could of went bad another suggestion was that the aem pully on the alter is about twice the size of the normal one maybe the pully is not charging the battery at idle any suggestion would be appriciated

 

let me guess, you have subz thumping at the stoplight, right?

If so that is your problem. Why would you underdrive an alternator? They have very very little resistance.

 

a kid once told me he checked the voltage coming off the alternator before and after installing the underdrive pulleys and there was a significant drop in voltage with the underdrive. which makes sense. low voltage -> more heat -> dead alternator. thats why i would personally never use them. and this guy is all about the bling bling, so it was a conscious decision.

 

not system at all in the car.....pully came with the car so i just swapped it onto the new high performan alter i did not think a problem would come of this

 

Test the voltage coming off of the alternator at idle and at higher revs and let us know what you find...

Another thing that it could very well be is a ground problem. You moved the battery so if you didn't do a good job with the grounding points and wire you won't have a good charging system. Also, what alternator did you get? Have you gotten it tested?

 

Yeah, make sure you ground down the paint of where you ground it. And make sure you have the shortest wire possible for your gound.

 

The length of wire doesn't matter if it is 0 gauge wire. The resistance on that stuff per foot is next to nothing.

Just make sure you have sanded all the paint and bs off of where you mount the ground at.

 

true true, I'd still do it to keep it tighty and for just good practice, but technically, no you're right