| T O P I C R E V I E W |
| Roy |
Posted - 03/11/2009 : 14:01:53
Ref: 1996 Jeep Cherokee with 4.0L inline 6 cylinder.
Neighbor said his dashboard water temperature lamp wasn't working. Bulb checked good, have voltage to the temp sensor, and bulb lights when the hot wire to the sensor is grounded. Per the Hayes Manual we have the only time the temp light will come on is if the engine gets hot and the temp sensor goes to ground. Seems strange. On most cars the temp light comes on in the "start" position as a lamp check. Cannot believe Jeep does not have this feature.
Does a Cherokee really not have a bulb/lamp check function????
Thanks, |
| 8 L A T E S T R E P L I E S (Newest First) |
| skunkhome |
Posted - 03/12/2009 : 23:05:52
quote:
Originally posted by olcowhand
quote:
Originally posted by Roy
My experience with coolant temp lights is that when they finally come on it is too late. 
Strongly prefer a temp gauge that allows one to see what is actually happening as it happens.
Exactly why I'm trying to find some tiny temp/oil gauges for my Massey 1010 diesel. I do NOT like lights!
My Kubota has a gauge but also has a whistle on the radiator overflow. According to manual if the whistle sounds take the load off and reduce speed till whistle stops sounding. |
| olcowhand |
Posted - 03/12/2009 : 18:21:31
quote:
Originally posted by Roy
My experience with coolant temp lights is that when they finally come on it is too late.
Strongly prefer a temp gauge that allows one to see what is actually happening as it happens.
Exactly why I'm trying to find some tiny temp/oil gauges for my Massey 1010 diesel. I do NOT like lights! |
| Roy |
Posted - 03/12/2009 : 18:06:54
My experience with coolant temp lights is that when they finally come on it is too late.
Strongly prefer a temp gauge that allows one to see what is actually happening as it happens.
|
| skunkhome |
Posted - 03/11/2009 : 22:08:48
I guess that is truly an idiot(ic) light. |
| Roy |
Posted - 03/11/2009 : 21:53:58
2nstoys,
"It sounds like there is no bulb check built in."
That's what I was afraid of. Unbelievable!!!!!!!!!!! 
Think I'll stick to my rice burners. No wonder Detroit is in trouble.
Thanks, |
| 2nstoys |
Posted - 03/11/2009 : 20:52:07
This is right off of alldata pro web manual:
The coolant temperature warning lamp lights whenever engine coolant temperature is too high. Battery voltage is supplied to one side of the indicator bulb when the ignition switch is turned to the On position. The coolant temperature sending unit is connected to the other side of the bulb. The coolant temperature sending unit is a thermistor that changes its electrical resistance with changes in engine coolant temperature. The sending unit is installed in a threaded hole that penetrates a coolant passage of the engine. When the engine coolant temperature is too high, the sending unit resistance is low. This provides a ground path for the indicator bulb, which causes it to light.
Notes
The diagnosis found here addresses an inoperative lamp condition.
If the problem being diagnosed is related to lamp accuracy, be certain to confirm that the problem is with the lamp and not with cooling system performance.
The actual engine coolant temperature should be checked with a test gauge or thermometer before proceeding with lamp diagnosis.
Turn the ignition switch to the ON position.
Disconnect the coolant temperature switch connector as shown.
Install a jumper wire between the switch connector and a good ground. The lamp should light.
If OK, replace the faulty switch.
If not OK. go to Step 2.
Turn the ignition switch to the OFF position. Disconnect the battery negative cable. Unplug the coolant temperature switch connector. Remove the instrument cluster bezel and the cluster assembly. Disconnect the cluster connector. Check for continuity between the engine coolant temperature (ECT) sensor signal circuit cavity of the cluster connector and a good ground. There should be no continuity . If OK, go to Step 3. If not OK, repair the short circuit as required.
Check for continuity between the engine coolant temperature (ECT) sensor signal circuit cavity of the cluster connector and the coolant temperature switch connector. There should be continuity . If OK, replace the faulty bulb. If not OK, repair the open circuit as required.
It sounds like there is no bulb check built in. |
| olcowhand |
Posted - 03/11/2009 : 19:12:39
Had a 97, and have a 98 Cherokee, but both with full temp guages, so I can't help you with the light. I'd think it'd have the test feature though. |
| doyoucesp1965 |
Posted - 03/11/2009 : 17:27:13
Roy... Next jeep tht comes in the shop I will see for myself if this be the case..Wish I had seen it yest as we just worked on a 96 or so today...front abs sensors and brake rotor's and pads.. |
