voltage question

[bigmike71 10+ year member]

hey guys i noticed today that my voltage drops to about 12.4 while driving and beating but if i turn on my heater it jumps to about 14.4. what is the problem and how do i fix it. thanks for any help

Click to read more...

 

[DammitJames 10+ year member]

is this switching from ac to heat? seems like an odd problem what kind of car?

 

[tommyk90 5,000+ posts]

Normally the opposite should occur.

 

[DammitJames 10+ year member]

Normally the opposite should occur.

was my thoughts unless switching from ac because it would turn the compressor off unless its going to defrost

 

[TMali 10+ year member]

seems to me like you have a second alt working off your heater fan

 

[bigmike71 10+ year member]

this is a 97 honda accord and it is turning the defrost on sorry about that. but i still cant understand why my voltage would go up with it on and down when it is off

 

[DammitJames 10+ year member]

this is a 97 honda accord and it is turning the defrost on sorry about that. but i still cant understand why my voltage would go up with it on and down when it is off

might have a voltage regulator/alt problem when you turn ac or defrost on it turns the ac compressor on so that the air is conditioned even if its the heat defrost(many people dont realize this but it comes on so that the moisture is removed from the air) when your compressor comes on your car idles up and the alt charges more i would defiantly get the alt checked because if your car is running it should be at at least 13volts and nowhere under if it is at 12.4 volts while driving your alt isnt even helping thats below battery voltage

 

[neverfinished 10+ year member]

seems to me like you have a second alt working off your heater fan

im thinkin the same thing. Check it and see

 

[bigmike71 10+ year member]

thanks guys this was supposed to be a 200 amp alt from E.A. it is right at a year old now so i may need to get another one. would like to find one with an external regulator

 

[DammitJames 10+ year member]

call nate and tell him your problem his alts last way longer than a year

 

[jdmferio13 10+ year member]

mot sure which models but it sounds like your eld is working.The honda have an eld in the fuse box that will shut the alt down for certain reasons resulting in perfomance and better mpg.It will shut it down to 12.3-5 cause it feels thats a good enough charge for the cars electronics.when it feels a load or stress on the cars system it will send a signal to the alt telling it to charge at 14.4.Im having the same problems I am trying to figure out how to bypass it.

 

[bigmike71 10+ year member]

i thought i had read something like this when you get it figured out please let me know. this is killing my power output

 

[jdmferio13 10+ year member]

what i would do is unhook the power from alt to fuse box and run one from the alt to the batt and check voltage then.Its a way of bypassing it but it might throw a cel

 

[DammitJames 10+ year member]

what i would do is unhook the power from alt to fuse box and run one from the alt to the batt and check voltage then.Its a way of bypassing it but it might throw a cel

no need to unhook the stock wires just run an extra one the power will take the path of least resistance which would be your run of wire nothing wrong with this i dont think it would throw a check engine light either but i could be wrong but this should have been done with the big 3... which should have been done when the HO alt was put on or even before...

 

[quins90lac 10+ year member]

i had the problem of my voltage only being in the 12's for about 2 days then while doing some checking i found out i had a lose ground tightened that and im back to 14.50. saved me $45 cause i thought the voltage regulator popped.