Governor

It was unusually hot here today so I ran the AC on way home from work..after about 7 miles I thought I heard a loud snap(like an electric arc or short)down by the fuse panel side of car but nothing stopped working. I got home and checked all fuses and they were good..I checked all fuses under the hood beside the battery and they were good so I thought it was a fluke. When I took the car out later I got about 5 miles and noticed that my temp guage went from in the middle to pegged in 1 second so I pulled over. The cooling fans were not running but the car did not seem that hot. I turned on the AC and both fans came on but when I shut it off the fans shut off also. Fearing the worse I turned the heat on max and started home..after about 2 miles the guage dropped to the middle again really quick and stayed there for a couple of minutes and then pegged again after I shut off the heat..not gradually but really quick. I have checked all 3 fan relays and they check good. Why is my guage maxing out and then dropping again and the engine does not seem overheated??

james93gxe

My first thought was the coolant temp sending unit, but the snap sound makes me think it could be something else. If I were you I would double check the fuses and relays. Also make sure the coolant temp sending unit has a good connection.

Maxzilla91

and check if ur coolant didn't disappear from your radiator. top off ur radiator fluid. just so that u know u're keeping everything cool under there..

Drivin Maxima

iTrader: (7)

I agree with James..........coolant temp sensor is a possability........................also I would check the contacts on the gauge cluster (i.e. pull out and look at harness and back side of cluster, and alsocheck the wires that come up from the bottom of the dash goin to the harness.....maybe they rubbed against some metal and wore through) Good luck

Governor

Thanks for the hints..the fluid level is good...when you say coolant temp sensor do you mean the one on the side of the gooseneck where the thermostat is or the one that controls the radiator fans?

Tarzan

The snap could be a short to the ground that fried one of the wires, probably under the dash

Governor

Yeah I am going to check under there tonight after work...seems funny that the AC still works if something got fryed in the cooling circuit.

Wiking

AC is separate.

The short to ground is probable if under hood. (? Short to +12V if in gauge assy.) The sound u heard makes it possibly dangerous and shorting more from vibration; take gauges off and check wiring. Should smell also...

Open/check fuseblock, SMJ's (super multiple junctions) at farthest left PITA corner..

Anyways its good to check the harness starting from temp gauge; its signal goes to ECU. (At zero ohm gauge needle goes up, at 3KOhm down):

http://www.cardomain.com/memberpage/748507/8

Governor

Thanks Wiking..I will check under the dash when I get home tnight....

Governor

When I hit on the dash above or right on dash face the gauge goes down to normal..I can tap and it jumps all over the place..is the gauge bad???I left it run for half hour and the radiator fans finally kicked on so the temp sensing circuit is working. Strange....that snap I heard worries me but everything but the gauge works...tough to get up in behind the gauges to see anything. Anybody ever have this gauge problem?

usmanasif

I would bet on the coolant temp sense as well. It has happened to me in a different car. Same symptoms.

Governor

could you tap on dash and make it jump all over the place?? the sensor is under the hood..how can tapping on dash effect sensor under the hood??/

hadman

iTrader: (21)

All I can say is the Coolant Temperature Sending Unit directly effects that needle in your dash. If you replace it you will probably see things resume to normal.
It's a relatively cheap place to start attacking the problem you're describing (about $25) and it's also easy to do.
Unscrew the old one, screw the new one back in.
*Note: replace the sensor when the engine has cooled. Place a rag underneath to catch some of the fluid that will escape (not much will).

Governor

ok Advance Auto has one for $9.00 I will get one tomarrow and try it. I unplugged it(one wire) and gauge went to zero. What about the other temp sensor on the other side of the sending unit??

hadman

iTrader: (21)

The rear half is probably fine. It would take alot for it to screw up. Start with the sensor itself (good price btw) and see how it works.

Governor

Ok I will let you know Friday how it does...

Governor

I replaced the temp sending unit and no change...one thing I noticed is that the gauge dosn't start going haywire until it gets just above halfway, then it starts bouncing back and fourth between maxed and midway. When the engine is cold you can hammer on the dash and it does not vary...so I think it only goes nuts about the time the engine reaches the temp for the radiator fans to come on..around 207f I think. any more Idea's?

Governor

Cmon guys...any hints???? It dosn't go haywire until it reaches midway on the gauge..gotta mean something............

hadman

iTrader: (21)

Well it's more common to have a bad sensor, so it was a logical place to start. Failing that, if you have a multimeter and you are comfortable removing the gauge cluster from the dash, you can check the voltage continuity of the gauge itself. It could be on the fritz.
I'm not sure what else to suggest. If you aren't sure about how to go about testing the gauges with a multimeter, you could still remove it and just swap it with a known working one from a local yard.
The only thing is, these are guesses at best. Would not want to see you keep buying parts that aren't fixing the problem, which is why I suggest getting the gauge out of the dash and checking for voltage continuity first.
Maybe this page will help you below. If not - I'm tapped out for answers dude.

hadman

iTrader: (21)

Hope this helps...

Governor

I appreciate your help hadman..the sensor was only $9 no big deal...I thinkin gauge also..never had cluster out before is it hard???

goon9

iTrader: (13)

My temp acts up, i know it's only the gauge. Because it's correct after i smack the dash.

hadman

iTrader: (21)

It's not too hard really, just time consuming. You need to remove the radio gauge bezel, the section over the steering column, and the section over the steering column. Having this section apart also makes it a good time to swap out the notorious 3rd gen bad clock for a working one (if yours isn't functioning).

Jbr8k

iTrader: (8)

I'm having the exact same problem and narrowed it down to the gauge cluster. I'll take it apart to see what the deal is.

Btw, check the stickies "craig brace's page" for gauge removal instructions.

Governor

Thanks a lot hadman and jbr8k...I am not sure I am going to remove the gauge cluster or not..I will check out braces page and see how difficult...It gets pretty hot here in the summer and a working gauge on an engine with 252k on it sure would be nice!!!