charging system

[123abc]

how many volts should i be making at idle i have a 85 amp alt and are only doing about 13.8 is this sufficient to run everything sniper,large fans ,lights, amp,fuel pump,aircon and charge battery any info would be good

[hybrid]

85 is probably borderline for all of that.
13.8 volts is perfectly healthy as long as it can maintain that while all of those accessories are on.
If you start seeing much under 13.5v I would be looking at the alternator.

Lets go on the higher side and say 20A for fans, 15A for fuel pump, 20A for aircon (compressor clutch and blower motor at full pelt), headlights (60w) 10A.
We are already at around 65A just on those.

[123abc]

i agree the battery is shagged anyway 675 cca its down to 400 cca now 6yrs isnt a bad run im thinking 100 amp or 120 should do the trick it doesnt get much higher than 13.8 even when driving at 60 ks

[123abc]

sometimes down to 12.6

[123abc]

and add the 600 watt amp, elec ign, big coil

[hybrid]

The regulator will make sure it doesn't go too much higher than that.
You can fry the battery too if the voltage is too high. 14 is about the max you will (should) see no matter how good the alternator is.

[123abc]

Battery is still holding charge I wonder if it's just not putting enough back in

[123abc]

would a 140 amp unit be too big and fry the wire

[hybrid]

No it doesn't work that way. It only outputs what is needed. The rating is the Max output.

Some higher output alternators need some rpm before they start charging, so you have to give the car a quick rev after its started. Mine is 100 or 120 (can't remember) and it doesn't have that issue.

[123abc]

new issue put new alt on ok , new 650 cca batt ok, start car ok runs great charges great system is running 13.6 volts have 14.4 at battery running and 12.4 stopped once car is running cant turn it off at ignition wont stop have to unplug the single wire at coming off the alternator and it cuts the car thoughts would the solenoid be staying closed because of the extra power now

[unilec5544]

new issue put new alt on ok , new 650 cca batt ok, start car ok runs great charges great system is running 13.6 volts have 14.4 at battery running and 12.4 stopped once car is running cant turn it off at ignition wont stop have to unplug the single wire at coming off the alternator and it cuts the car thoughts would the solenoid be staying closed because of the extra power now

If the solenoid was staying on then the starter motor would be running, sounds like an issue with the ignition switch, do you have a volt meter?

[123abc]

yes
just strange it was wired the same with old alt i might just wire it a a single wire see if that helps
when you turn the key off radio goes off as well only the engine
stays on

[Shaunp]

So the engine runs on right? if so you need to fit a diode to stop the power back feed google a circuit for , you find one on the MSD site they supply a diode with the 6AL kits

[LeglessOne]

Check the aux post on the starter solenoid - the one that feeds 12v to the coil when the starter solenoid is pulled in. I have had 2 solenoids (scott drake) weld that contact closed and did exactly what your describing. When they fail it feeds 12 volts straight to the coil even though the ignition switch is off.

Replaced mine with one from Ashdown Ingrams and had no problems since.

Shane

[123abc]

spot on shaun went to jaycar bought the diodes soldered one into the wire from the reg and presto car turns off def power feed back in the system