troy fritz

My volt gauge sits at 14 to 14.5 . When I turn on my heater it drops to 13ish. I put new battery and alt on it and still does it . Whats the problem? Sometimes 12.5 volts.? If I turn heat off it goes back to 14 to 14.5.

Abovetimberline

are you looking at the stock guage,mine drops that far at least. If you have a volt meter check it at the battery when your fan is running and see what it is.

troy fritz

It also does it when I turn on my offroad lights on the roof. Ill check the voltage . Its running at 13.64 with motor running and 13.61 volts with fan and motorrunning .With heat on full blast its reading 13.39 volts . All at the battery. Is this good?

captainwoot

Anything above about 13.2 with your acc's on is pretty good, the stock guage just isn't quite accurate enough

jonnyb78

you should be ok at that voltage. do your headlights dim when the fans or anything else kicks on? you could always upgrade to a higher output alternator

troy fritz

No , everything is strong. Thanks alot guys.

trans_am7935

i have the same problem but my guage drops down to 10 volts and sits in the red when i turn my lights on. it never even sees 14. i was told to upgrade to a 160 amp alternator, but i have the renix system, but with a high output motor...any ideas? also the battery is brand new, i have an 85amp alternator right now.

smitysjeep4x4

i dont know to much about renix system i would defently upgrade or get a new alternator becuse the alternator should be pushing the batter with accerorys on aound 12 to 14 v check with voltmeter

4.3L XJ

When the alternator is charging, or being heavily used the voltage will drop. It should pick up if the engine is reved a little. Everybody's does it unless you have a huge alternator.

trans_am7935

but mine gets so bad at night it drops below 9 at idle and the radio shuts off....then a min later it goes back on when it charges back up

prerunner1982

my gauge always reads in the red... but checking it at the battery I always have close to 14 volts. I think I have a loose connection at the alt.

5-90

If you're checking with the accessories on at idle, it's not a valid test. Most alternators are good for about 40% of max rated output at idle, and you can run that out in a hurry (figure that as ~24-32A for OEM RENIX, 36-44A for OEM HO.)

First thing you should do when you see that happen is run your idle up to 1200rpm or so - which works out to a spindle speed (at the alternator) of 3500rpm or so - where you can get full output. You should see your lights brighten up and your voltmeter pick up.

And, the IP voltmeter is a notorious liar. Always back-check suspicious readings using a decent voltmeter (typical multimeter will usually serve.) I'm not sure where the IP voltmeter gets its "sense" connexion, so I can't really help you there. However, if you're consistently getting 13.6+VDC at the battery KOER, you've not got a loose connexion at the alternator - that's just fine.

prerunner1982

After thinking about it. I have been having a weird problem on very hot days. I know that heat is not good for electrical circuits and if the connection at the alt isnt good then this might be my problem. Luckily it is cooler here already (mid 80*s) and I only had the problem a couple of times this year as it happens when temps are above 95*s. I will definately crawl under thier this weekend to button things up though.