92 vx new alternator voltage?
 

i got a cigarette lighter voltmeter and noticed my voltage fluctuates between 12 and 14? so i thought it might be something in the fuse panel to the cigarette lighter but i put a meter on battery and it matches what the voltmeter in cigarette lighter has. its a new alternator and was going to take it back to shop that installed it but just want to make sure it couldnt be something else causing it? does vx have resistor block? i found other civics have it but i couldnt find it for the vx? sounds like to me the regulator but what you guys think?

is the brushless alternator really necessary? i am not running one right now.

Depends on when you're seeing what.
If you're stopped waiting at a light, at idle, foot on the brake, blower on, headlights on, and such, I'll see 11s. If I'm over 2000rpm driving with no extra electrical load, coming off a cold start, I'll see 14.5. I think it's normal.
If you're parked just watching your voltage, no changes to engine speed or electrical loads, and your voltage is bouncing from 12-14v quickly, then I'd say there's a problem, likely w/ the alternator, or connections to alternator or battery

^THAT.

modern alternators do a pretty good job of keeping up, but they need some speed before they get near their peak outputs.

then you start getting into stuff like temperature compensated target charging voltage and clutched pulleys and other fun stuff and all conventional wisdom goes out the window.

ok just to clarify this is when its idling and warm with no load or driving and no load my voltage will change from 12 to 14 with nothing on but the radio.

so does anyone know what im referring to about the resistor block? does the vx have one?

do you have any other symptoms besides what your meters are reading? lights flickering or changing in intensity, gauges wiggling? what were the symptoms causing you to get the alternator replaced?

since you just had a shop put it on, you could just take it back and tell them what youre seeing. maybe they left something loose, or the new alternator has a junk diode. if its something they did, they should fix it. i'd be very leary about giving them any additional money though.

i have no idea on the resistor block

Clean the ground connections, especially the engine ground to the radiator support (wire from valve cover bolt to support metal). Voltage fluctuations like that are not normal. You can test the grounds with a volt meter. Start at the battery negative terminal and touch the other lead to various ground points with the engine running. If you detect a voltage, anything above a very small amount there is resistance in that ground connection which could be your problem.

regards
Mech

the alt was bad for sure but we had a foot of snow so i was at the mercy of the shop. i know the shop will take care of the alt no problem. i got no low dimming lights or gauge issues but i do have an engine miss i have been chasing since ive had it. and i was hoping it was related to when the volts goes to 12 but no change???

i replaced the ground cable on rad and trany. i will redo the grounds. hey call call on the volt check! i will try that! thks!

There might not be anything wrong. Honda uses alternators with two output levels and an electrical load detector. The ECU will reduce alternator output if there isn't much load on it. On my '91 Civic, any speed above 40 MPH should be 14 volts regardless of load. But I'm usually forcing the alternator into the low output mode. :)

i also have a 91 civic si and the cigarette lighter voltmeter stays around 14 all the time idling or driving.

This. The VX has a Special Voltage Regulator. In My car (1995 VX), If I'm running a load greater than 10Amps, Turn on the A/C or go over 40MPH it puts out 14 volts. My Dad has a 1992 VX and it does the same, except the speed is not a factor.

where is the special voltage regulator? my alt is not oem honda. mine goes from 12 to 14 at idle or driving with no load. is this normal or not?

If it jumps around at idle, it is not normal. If it changes depending on electrical load, it is normal.
Mine is at 12.3ish at idle with a warm engine and light electrical load (no A/C or headlights, no fans), but increases whenever load does, or other parameters already mentioned. I looked in my factory electrical troubleshooting manual for the exact conditions, but I think it is in the main manual.

With the recent addition of a ScanGuage to my F150, I became aware of the voltage variations during driving that the simple needle pointer on the dash was keeping me clueless about. With low numbers of 13.8 to high numbers of 14.9 or 15.1 and a year old new replacement alternator, I became suspicious. I started reading up on grounding issues and how poorly the factory takes care of such things.

I looked up the basic improved grounding options and started to replace my corroded ground straps with heavier cables. This helped to stabilize the voltages but the numbers still did not settle down to my liking. I then added a direct ground from the battery negative terminal to the back of the alternator where the alternator is grounded to the engine block. This new cable was a #4 gauge cable with copper connections at both ends. The new cable caused my voltages to stabilize in the 14.1 to 14.3 area unless I was using an electrical device. Even then the voltage is stable with a slightly lower reading. I had no clue how much difference the additional grounding cable could make in making the electrical system more efficient.

A friend once claimed that just heavier cables to the battery would help make the alternator and battery last longer. No telling what the additional cable from alternator to battery will do long term.

There are several different Youtube presentations that deal with grounding upgrades. Watch all of them and get a good idea of what options are possible. Just wish I had know about this ten years ago. The educational opportunities on this site are many.

i paid closer attention to it today and noticed at 50mph it changed from 12.3ish to 13.8 ish. so i guess this is by design and normal for the vx?????

Hondas have an additional voltage or load regulator to help in fuel economy. :eek: They call it the ELD, it turns the alt on when battery voltage falls below 12.6 volts. I dont know the upper voltage, but think its near 13.8 to 14 volts. It trys to make the starter battery bare the load of the electrical system vs constantly powering the car by the alt. Theres plenty of stuff online how to disable it.

if its suppose to work this way thats fine its just trying to find people that know this so we what is a problem and not? so how do you troubleshoot this? and how low is to low? is the eld same as resistor block?

and i found this from another forum - http://www.civicforums.com/forums/21...-detector.html

I just checked my Fiesta (original motorcraft battery) and an agm battery that was given to me. The Fiesta has not moved since Sunday and the battery reads 13.2 volts. The agm battery has not been touched in two months after being charged and it reads 12.8 volts.

regards
Mech