What could the problem be?

[Gamblr]

Hey guys,

I had my cj sitting in the garage for 6 months and obviously battery was gone completely I jump started it whenever I wanted to work on it but just got a new battery and my head unit and aircon and also the volt gauge I have wired in won’t work anymore except when I give it a good rev the aircon/heater will start working and gauge will turn on but the head unit won’t at all. I’ve checked all the fuses and everything is intact

What could the issue be?

Cheers

[Gamblr]

And power doors won’t work aswell

[Mooman]

As a guess since everything works when revved I'd say you have a low voltage problem, possibly caused by a short circuit somewhere or a faulty alternator/serpentine belt.

If you have a multimeter check the voltage across the battery and have someone rev the engine. If it's low, less than 10VDC then your charging system or battery is no good. When revved it should be around 14VDC (as long as it's over about 12VDC the battery will charge).

Also as you have added in a gauge check the wiring joins, it's possible that after sitting they have corroded or come loose causing a poor ground or short circuit (be sure to check inside any insulation).

Not 100% sure but constant jump starting may have caused some issues to the electronics. If you can get an OBDII reader on your car it may show some fault codes you can work on.

[bumblebee]

Sounds like you just need to adjust the throttle so it idles around 4000 rpm and your home and hose.

Lol

Seems a bit odd with a new battery installed

Check the basics. Whack a DMM over the battery and see what kind of voltage your getting across the terminals with car running and go from there

When was the last time the battery terminals were cleaned?

[himynameisdaniel]

Don't forget to check fuses for etacs ecu in glove box.
It controls central locking, mirrors, windows, etc

[Gamblr]

As a guess since everything works when revved I'd say you have a low voltage problem, possibly caused by a short circuit somewhere or a faulty alternator/serpentine belt.

If you have a multimeter check the voltage across the battery and have someone rev the engine. If it's low, less than 10VDC then your charging system or battery is no good. When revved it should be around 14VDC (as long as it's over about 12VDC the battery will charge).

Also as you have added in a gauge check the wiring joins, it's possible that after sitting they have corroded or come loose causing a poor ground or short circuit (be sure to check inside any insulation).

Not 100% sure but constant jump starting may have caused some issues to the electronics. If you can get an OBDII reader on your car it may show some fault codes you can work on.

Just finished work, and hooked the battery up to the multimeter it read just above 12 when engine was turned off and then 11.7 when engine is on and being revved so definitely the alternator the battery and service lights also come on when being revved so time for a new alternator

[Gamblr]

Sounds like you just need to adjust the throttle so it idles around 4000 rpm and your home and hose.

Lol

Seems a bit odd with a new battery installed

Check the basics. Whack a DMM over the battery and see what kind of voltage your getting across the terminals with car running and go from there

When was the last time the battery terminals were cleaned?

Lol atleast my idle will sound meaner, but yeah first thing in the morning I’ll give the terminals a clean before going to pick up a new alternator

[bumblebee]

Before you go nuts with a new alternator what do you want to do with the car down the track?
If you want to build an audio monster car then grab an alternator from USA. Theres a lot who make 370Amp lancer alternators delivered for under $800

Have a chat to these guys


http://www.mechman.com/alternators/mits ... 2008-2015/

When my alternator lets go i will get one of these