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Discussion Starter #1
Ok, to all the honda electrical people, my civic dont charge past 12.5 volts. I have relocated the battery to the trunk. I have brand new wire going from the ground the the frame, and yes the connection is good. I have new wire going to the front also. Ive tried 3 different batteries, 2 ecu's, 3 main fuse boxes, different ignition key to fuse box wire harnesses, different engine harness. Ive tried about everything that i can think of and still cant figure the problem out.

As of yesterday i found out that if you take the big white wire off the top of the alternator, and check the voltage, the alt puts out 14.5 volts. But as soon as you hook the white wire it drops back down to 12.5 again.

If anyone has a clue or can give me something to check that would be great. Even though chances are that i have already checked it i will still be happy with clues. Forgot to mention that i have a 90 civic Si. Thanks to all that reply.
 

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R2.....Zap Balls
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What size wire do you have running to the battery from the front of the car? How long is the ground for the battery and where is it grounded?
 

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Discussion Starter #3
What size wire do you have running to the battery from the front of the car? How long is the ground for the battery and where is it grounded?

I have 4awg ground and power wire. The ground goes to the hold down piece for the spare tire. I also have a ground going to the front of the car that bolts to the tranny where the clutch cable holder piece is.
 

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I have 4awg ground and power wire. The ground goes to the hold down piece for the spare tire. I also have a ground going to the front of the car that bolts to the tranny where the clutch cable holder piece is.
Move the ground to another point. Somewhere within 12"-16" of the battery. Make sure you clean the paint off and have bare metal on the spot where you are grounding it. On the other, did you run a ground wire all the way to the front of the car to ground on the tranny? If so you don't need it, just run the ground from the tranny to the frame rail like it was Factory.
 

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Discussion Starter #5
Move the ground to another point. Somewhere within 12"-16" of the battery. Make sure you clean the paint off and have bare metal on the spot where you are grounding it. On the other, did you run a ground wire all the way to the front of the car to ground on the tranny? If so you don't need it, just run the ground from the tranny to the frame rail like it was Factory.

Ill move the ground to a different point. Although the point its at now is a clean, no paint or rust area. The battery is located in the right rear of the trunk so its not to far from the grounding point. But ill try that too and find a spot thats closer.

Yes i did run a wire to the front to the tranny. I never used to have it that way but since ive had this problem for a while i decided to try that out and see if it helped. I do have a big grounding strap that goes from th tranny to the frame rail.
 

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Im having the EXACT same problem, and I have done the same battery relo (while I was troubleshooting the problem), tried the same things (and then some) and I am absolutely fucking stumped. The only difference is mine is a 95 CX, but Im sure whatever the fuck it is, we share the same problem.

Ill let you know if I figure it out, please do the same for me.

The last thing I have to try is the starter, its a long shot but Im going to try anyways.
 

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can either of you temporarily hook the battery up in a stock fashion to test charging voltage?
This may not be a 'quick' test, but this will eliminate some of the variables, and if your as stumped as it seems, then you have to cover all the basics.

If it changes, then it has to do with the relocation. (Wire AWG, new grounds, wire terminals, etc.)

If not, then you know it's not the mod, it's related to something else.

Also, do you know how to perform a voltage drop test?
 

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Ive covered all the basics. Its definitely not the relocation thats causing the problem, I relocated the battery AFTER I started having problems. My voltage dropped about 1-2 mV after the relocation, not enough to cause a concern.

A brief rundown of the history:

-New battery and alternator, still had the problem
-Several tests later (and some part swapping) I deemed the new alt was crap (despite it testing good twice), got one from a fellow forum member and problem solved.....for a week or so.

Now Im back to square one, its doing the same shit it was doing before I started troubleshooting.

Theres a couple more things I have thought of trying, but I doubt it will fix the problem.

I live in Lacey so were close. What are you doing this weekend? :)
 

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IT doesnt charge past 12.5v? So B+ V is 12.5 with the engine running? What does it drop down to when the engine is turned off?
 

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Discussion Starter #10
yeah ive tried putting the battery back in its original spot and just like atmosfear said it only changed like .1 or .2 volts.
 

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yeah ive tried putting the battery back in its original spot and just like atmosfear said it only changed like .1 or .2 volts.
well, if you're confident that when you put it back to 'stock', you eliminated ANYTHING (and everything) you changed when you mod'd the battery location, then it's not your battery location that's at fault.

Don't forget to check the basics. Make sure you're alternator and battery are good. Any decent parts store should be able to check thiese for free and do it on car as well.

A service manual will tell you step by step how to test all of these systems. If you search around, you can find the .pdf manuals you need.
 

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your alternators have voltage regulators inside the case and despite it being new it might be malfunctioning all it consists of is a bridge with one way diodes and they are not expensive to replace but you have to know what your doing. and always remember the alt is able to put out almost 15 v but unless you need 15v it might only charge at 12.5 or 13
 

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Discussion Starter #13
yeah i understand what you guys are all saying. the alt is fine, cause when i take the big white wire off the top of the alt, the voltage there goes up to 14.5 like its suppose to. but as soon as i touch the wire back on the alt, it goes right back down to 12.5 volts.

i have also had the parts store check the alt 3 times before i installed it on my car.

its gotta be something other than the battery, alt, main fuse box, but what it is i dont know.
 

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^^Im with you man, again...same thing here.

As read from the OEM serv. manual, with the headlights on, the heater on to at least 3 and/or the rear defrost on, this should trigger the ELD to tell the alt "hey charge the battery".

Ive been through the basics: the alt is good, the ELD inside the main fuse box is good, the grounds are good, the battery is good, ALL wiring associated was checked for continuity and voltage (where applicable) and all checked good.

I have performed every check that was indicated in service manual w/ the exception of a few that I do not have the proper test equip for. And to rule out those...I swapped parts w/ known good ones (ELD and ECU).

Im going to try to swap the starter (I know it shouldnt matter but I have a theory I would like to try) and see if that does anything. Then I plan to do another current draw test, I know if a battery is drained to a certain point, the alt is not capable of charging it and may possibly burn up the alt.

Oh...and Im not getting a batt. light, which according to the serv. manual I believe I should.
 

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have you tried or have to tools to get resistance reading of the length of wire them selfs?
 

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Discussion Starter #16
is that just a volt/ohm meter?

i also do find it funny that my battery light does not come on, even though when i drive with the lights and heater on, it drains the battery enough that it makes my temp gauge and my tach pulsate with the blinker cause the battery is so drained.
 

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Yeah man, 0-negligible (a milli-ohm), There are no opens or anything of that nature. Im pretty sure the OP will be able to say the same thing.
 

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I have 4awg ground and power wire. The ground goes to the hold down piece for the spare tire. I also have a ground going to the front of the car that bolts to the tranny where the clutch cable holder piece is.
My relo kit came with 0awg cable. I dont think 4 is big enough, but that wouldnt affect the voltage. Only amperage. The volt reg sounds suspect to me. Keep us informed. This good to know b4 I do mine! And good luck!
 
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