blaze2fury

So my 84z has been running great other than it has been draining the battery. I had a 7 year old battery in it that has ran my 79z with no issues, but in the 84 when I turn on the electrical fan by turning on my a/c (which I don't think is suppose to happen when you turn the a/c switch to Max.) The battery gauge drops to just a hair above 13, and then when I turn the headlights on it drops right on the 13v line. Is it suppose to drop that much? So I put a 750cca battery in the 84 to see if it will fix the issue because the old battery was only 450ca and was only reading 325ca when I charged it. Any thoughts on this? Is that normal for the battery gauge to drop that much when the electric fan is on? And why does my fan only turn on when I turn the a/c on? Thanks.

sofakingdom

iTrader: (1)

Sounds like your alternator doesn't have enough nads to keep up with the electrical demand. It's supposed to be able to put out enough power to run everything electrical, plus a bit extra to recharge the batt after a start.

Batt CCA is irrelevant.

The comment about the fan and Max AC makes no sense. There is no reason for the radiator fan NOT to run when the AC is in Max, and in fact, has the most need to be running at that time.

blaze2fury

I just got the alternator and it is an 94amp. I figured that was enough to keep it charged. And my fan dosnt turn on by itself. Not even when the temp is at 220 or higher. I have to turn the switch to max to get it to turn on.

OrangeBird

iTrader: (1)

Hook a real voltmeter to the battery terminals and check it , the dashboard gauges in these care are notoriously inaccurate . Does the battery eventually need to be jumped to start the car ? If not , if the car starts fine and it's only the low dash gauge reading that's making you think there is a problem , the real problem may well be the gauge itself .

blaze2fury

If I leave the fan on it will eventually drain the battery even if the car was running. It seems like its not getting charged but i changed the alternator just the other day and its still doing the same thing. will run for a couple days and then eventually the battery will be dead.

mmadden55

Check the water level in the bat if it is not the gel type and add DISTILLED water to bring the level to the top of the slots in the fill holes, Make sure your grounds and positive cable connections are clean and tight. If that does not cure it try a fresh battery. As for the fan check your ground connection to the temp switch by grounding the lead to the bat neg side with the key on if the fan works the switch is bad if not look at the relay. Single fan?

blaze2fury

Yea its a single fan, Just put a brand new battery in last night. Ill check the grounds coming from the fan and see if that fixes it..

mmadden55

On the passenger side there is a temp switch that is supposed to turn the fan on. It is on the passenger side. Ground the lead from that with the ignition on and if the fan does not come on it is the relay if it does it is the switch. We know the fan works because it comes on when you switch on the max ac

blaze2fury

Ok I will try that, But what if the gauge is correct and its drawing too much power. How do I fix that? As in where should I start looking? I don't have much experience with the electrical side of cars. Just a wrencher lol.

sofakingdom

iTrader: (1)

With an alternator that has more nads.

QwkTrip

iTrader: (22)

If the alternator output changes quite a bit with just small changes in engine speed (rpm) then a smaller diameter alternator pulley might be the easiest solution. Might need to have shorter belts depending how it effects belt length.

You can check the charging deficit by putting an ammeter on the battery cable and measuring how much current is being sucked out of the battery while idling. Then slowly increase engine speed until the battery stops discharging and record the engine RPM. Then you can calculate what percent change you need in alternator pulley diameter to correct the issue. If the change is too much then that's when you need a larger alternator.