voltage drops bad???

[cleanmerc01 10+ year member]

i hooked up isolator to alt then another line form isolator to back battery. and the battery just a regular car battery same as front

 

[cleanmerc01 10+ year member]

ground to the frame. when car running the front battery bounces around on volt gauge 12-13 i got and back one never moves stays about 12

 

[cleanmerc01 10+ year member]

i think i either spent too much on **** i didnt need or i hooked something up wrong

 

[pro-rabbit 5,000+ posts]

If you only get 13 volts on the front battery with nothing on with the car running you have wiring or alt issues. The rear battery is not hooked up correctly if you do not get above 12V back there. Check your wiring and ditch the isolator.

 

[brian84corvette 10+ year member]

you are having serious problems if the car running = 12.anything volts from the alternator

its suposed to be 14.4 but 14.0/13.8 would be the bottom line of acceptable.

id take your alternator to be tested.

also try charging your batterys up.

 

[cleanmerc01 10+ year member]

so i should test with nothing on and see if i get 13v or so with car running. and test at alt and should get 14 right. im thinking that isolator is the problem. like i said the front battery reads between 12-13 volts (bouncing around) and back battery stays about 13. and the two amps are hooked up to rear battery. i just want the voltage drop to go away thats why i installed 2 battery. so any help could help

 

[brian84corvette 10+ year member]

engine not turned on - measure your battery voltage front and then rear. write it down on some paper ( be specific. if your meter says 13.877 volts than thats it )

start up your engine

measure your front battery - and then your rear battery voltage - write it down on some paper

post back here and tell us what you wrote down please.

 

[cleanmerc01 10+ year member]

alright i thought it was the ground to big amp change and still the same. the front battery is reading 11.2 and back battery is reading 12 with car off. going to autozone to have them test front battery. i went to audio shop and they said prolly ground to big amp. i just confused even guy at audio shop said i shouldnt have any voltage drop with my set up.

 

[cleanmerc01 10+ year member]

alright i thought it was the ground to big amp change and still the same. the front battery is reading 11.2 and back battery is reading 12 with car off. going to autozone to have them test front battery. i went to audio shop and they said prolly ground to big amp. i just confused even guy at audio shop said i shouldnt have any voltage drop with my set up.

 

[RAM_Designs 5,000+ posts]

Ditch the isolator. Run 1/0 from front batt to back batt, and then to the amp. Ground from amp to back batt and then to the frame(or you can ground each separately, but it's not needed). If your front batt is only at 11.2V, it's bad. Check the voltage at the front and back batt when the car is on.

 

[bubbagumper6 5,000+ posts]

;7410721']voltage drop is good

HO alts= bad

you need a cap

;7410739']dont listen to him' date=' get rid of your back batt, get a giant cap. and youll be all set[/quote']

;7410756']shut up noob. People who run PA arent allowed to talk //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

;7410779']yes' date=' ditch the battery, buy a cap. and crank the gains.[/quote']
Just stop. You guys aren't being funny your just being dick heads. This is exactly why this site has gone to ****, because when new people come in and ask questions, they either get blasted or get fed false information. If you don't want to help him then don't bother posting.

 

[bubbagumper6 5,000+ posts]

Sounds more like a problem with your alt. If it's not working correctly you'll just be running your batteries down which would explain your low voltage readings.

 

[cleanmerc01 10+ year member]

ok this is what i found out.

1) When car running the front battery reads 14.7 witch is goodand the line from isolator the back fuse reads 14.7 without back battery being hooked up. when hooked up it drops to 12.

2) when we mounted the fuse holder the screw was hitting frame and also touching connector shorting out i think.//content.invisioncic.com/y282845/emoticons/redface.gif.62fdbfe1a101588a808c4cff71bcb942.gif i removed screws and the hooked up volt guage to frame and positive side of battery and i get nothing.

This might be a stupid question but shouldnt i get a reading?????? or does the ground wire to battery have to be hooked to frame to make a loop current. i hope it was just the screw hitting frame and connector shorting system. but i will wait to her from you guys before i hook things back up.

i will be waiting by computer to find out lol

 

[bubbagumper6 5,000+ posts]

If battery ground is not connected to the chassis of the car, then no you will not get any reading on your dmm. It sounds like you found your problem though, just be careful when mounting that fuse holder so that it can never short like that again.

 

[cleanmerc01 10+ year member]

thx you guys i appeciater the help. as for the fuse holder its getting zip tied this time and i will make sure when i have someone helping do the install i will check everything first lol