ArgoGirb

putting steps on the jeep i found this under battery,pops up a bit when batt.removed,2 wires from it.Then pulled batt.trayand found a box with just a vac.line to it,no wires.Any thoughts ?

CrazyWJ242

round springy disc is the Battery Temp Sensor allows the alternator to charge faster as it can up the voltage until it hits a threshold and slows down the charge coming from the alternator...

the other is the vacuum reservoir... pretty important deal for engine off braking... keeps your brake booster functional for a few presses of the pedal... after the reserve is gone, you have no braking assist and you need to be ready to stand on that pedal!

ArgoGirb

Thanks crazy,kinda thought the box was a reservoir.Glad i didnt trash the temp sensor!

Mr White

iTrader: (1)

The 03 sport doesn't have this or maybe it was a forgotten item when mine was built

CrazyWJ242

The battery temp sensor may only have been with the high amp alternators... just a thought of why it might not be there...

but surely you have a vacuum reservoir somewhere... every vehicle with breaking assist has one... just a matter of where they decided to hide it... my WJ its in the battery tray itself!

Mr White

iTrader: (1)

My old 89 xj had it nicely place in the wheel well, which we removed to under the hood. On this tj its probably in plain view just haven't taken notice of it.

ArgoGirb

Thanks for the input guys,for the record the build sheet i got from Chrysler i have 117 amp alt.Mr.white my reservoir is underneath the batt, tray,which is also where the plug for the temp sensor is.

ArgoGirb

Was just at the wreckers,seen a 97 TJ,4.0l stick,had temp sensor in bat.tray, hmm