Engine Gauge problem

i did a quick search for a topic. im sure there might be one.

My Oil Pressure gauge sits on the scew on the right past 80, it just sits there, used to work, but i havent done anything to it... it doesnt fluctuate at all leading me to believe that it just doesnt work.

Also my temperature gauge doesnt work anymore... it didnt work when i bought my jeep... but when i replace the stock muffler with a melo-tone it started working..... i know its wierd.. anyway.. its gone back to not working... every once in a while it will try to go up to running temp readings, but in the process it gets half way up and fails.

The temp sensor is about a year old. but it was new when the problem originally occurred



can i get some advice on what to do? im running water in my radiator at the moment and dont want to risk over heating.... and theres no real way of monitoring my temp.

Oil pressure sending unit, replace it.

If you take the wire from the temp sending unit and ground it what does the temp gauge read?

Also, it really really really helps when people post the year/engine/trans and any other data that may be effecting things.

The oil pressure sender could be broken, or the guage itself. I'd say the sender is easier to replace, and most likely cheaper.

1995 Jeep cherokee sport AX-15 Trans np231j T-case

running 231,xxx miles

oh yea... i dont think ive ever spotted the oil pressure sensor... can some one give me a general reference of where its located?

Djmack said:

oh yea... i dont think ive ever spotted the oil pressure sensor... can some one give me a general reference of where its located?

Click to expand...

Look at the thing that the oil filter screws into. It's on there above the filter. It's in such a place that when removing the oil filter it can be broken off if you're not careful, or if you take it to JiffyNoob.

haha lol.. okay... yea in that case, ive unplugged the wire a couple of times for certain reasons... just working on it..

anyway. if thats the case, i just need to come up with $30

I see what you're saying

ok

and as far as grounding the temp sensor wire... do i just unplug it and gap a wire between either prong of the plug to ground it?

Got an old school test light? Ground one end of it and put the pointy end into the terminal in the end of the temp sender wire. (single wire sender) The gauge should slowly sweep from one end to the other.

Unplug the wire and ground it, block.. screw, bolt, etc.

so.. lets say it does sweep across... this means my sensor is bad... correct?

and.. lets say that it flickers and fails.. this means my connection is bad... some where? correct?

yes - if it sweeps across that means the sensor simply isn't varying in resistance properly. If it jitters around and then settles down again you have a loose connection or your gauge is screwed up.

The sender provides resistance to a coil in the gauge, which produces a magnetic field that pulls on the gauge needle. As the resistance varies, the amount of current flowing into the coil varies, which produces varying levels of magnetism.

With temp sender wire disconnect (infinite resistance) the gauge should go to bottom position, with temp sender wire directly grounded (no resistance) the gauge should go to highest position. If something else happens then you have a problem with either the wire or the gauge.

My guess is that you have a short to ground somewhere on the gauge wire since it is always pegged.