JeepinSoldier Posted October 11, 2009 Share Posted October 11, 2009 I just swapped my 1990 idiot light cluster for a full gauge cluster out of a 86 or 87 Cherokee. I liked the look of the old school gauges. However it does not seem to be working properly. The temp gauge starts at about 210 and then maxes out to the right and stays there. The volt gauge seems to read high. Finally, the tach seems to read under revs by the engine sound and is very slow responding to revving the engine in neutral. The Spedo, oil pressure and fuel gauges seem to work fine. Here are pics of the install before starting the engine and after driving a little. Any ideas? I used the swap instruction here and on the NAXJA website. I swapped the oil and temp switches for the EXACT part numbers stated on the NAXJA site. The water temp sender is a Wells TU 108. Now it says on the box 'water temperature switch' I assume I need a sender, and the switch is the same and just turns on a light - but I used the part number listed. I just might try a newer cluster. Too bad - I like the looks of this one. Link to comment Share on other sites More sharing options...
Yesterday's Danish Posted October 11, 2009 Share Posted October 11, 2009 The tach should have a pentometer on it. Pull the tach out of the cluster and you should see a white screw. You turn that screw to adjust the tach. I've found that turning it clockwise calibrates it for a 4 cylinder and putting it in the middle adjusts it for the 6. I'm not sure if the older clusters have that pentometer. Someone might able to answer that. Link to comment Share on other sites More sharing options...
glundblad Posted October 11, 2009 Share Posted October 11, 2009 I did a direct swap with the newer gauges and it worked fine. Prior to the swap, I was getting too cold of a reading on my temp gauge. But after I performed the gauge swap and replaced the temp sensor it worked fine again. I still have the box from the sensor. It was called Duralast TU108 Temp Switch. Link to comment Share on other sites More sharing options...
Eagle Posted October 11, 2009 Share Posted October 11, 2009 You can't estimate revolutions by engine sound. If you had a 4-cylinder tach connected to a 6-cylinder engine, it would be reading too high, not too low. Why? Because all the tach does is count pulses. A 4-banger makes two pulses per revolution, a 6-cylinder makes three pulses per revolution. So the 4-cylinder tach would see three pulses and say, "Hmm, that's 1-1/2 revolutions." Borrow an idle tachometer and use that to verify the actual RPMs at idle, and how it calibrates to the tach in the cluster. No, the old style ("Type 1") tachometers do not have the potentiometer. Check your voltage with a voltmeter. It isn't in the red, and normal operating voltage should be between 13.6 volts and ... ??? 14.2 volts??? ... don't remember the upper limit off the top of my head. Suffice it to say that the system is nominally a 12-volt system, but it doesn't actually run at 12 volts. I don't know what to say about the temp gauge. After the vehicle has sat long enough to completely cool off, does the needle drop to 100 degrees (fully to the left) when you turn on the ignition? If the ignition is on (engine NOT running) and you remove the wire from the temp sender, where does the needle point? If you then ground the wire directly to the engine block (or head) where does the needle point? Link to comment Share on other sites More sharing options...
JeepinSoldier Posted October 12, 2009 Author Share Posted October 12, 2009 Borrow an idle tachometer and use that to verify the actual RPMs at idle, and how it calibrates to the tach in the cluster. Check your voltage with a voltmeter. It isn't in the red, and normal operating voltage should be between 13.6 volts and ... ??? 14.2 volts??? ... don't remember the upper limit off the top of my head. Suffice it to say that the system is nominally a 12-volt system, but it doesn't actually run at 12 volts. I don't know what to say about the temp gauge. After the vehicle has sat long enough to completely cool off, does the needle drop to 100 degrees (fully to the left) when you turn on the ignition? If the ignition is on (engine NOT running) and you remove the wire from the temp sender, where does the needle point? If you then ground the wire directly to the engine block (or head) where does the needle point? Thanks for the advice! Exactly the help I needed. Ill borrow an idle tach and a volt meter to check those gauges tomorrow. I just checked the temp gauge per your questions. The truck has been sitting for hours and is completely cold. Turning the ignition switch to the 'run position without starting dropped the needle to the line before the 210 line. It does not drop to the left (100). Disconnecting the wire at the sender does not do anything - the needle stays at the line before the 210 line. Grounding the wire to the block or head makes the gauge needle move all the way to the right WAAAAY past 260. Almost to the small screw in the gauge before the wire was removed from ground. I diddnt want to fry the gauge. Starting the engine and letting it run with the wire connected moves the needle from the line before 210 back to 260. Link to comment Share on other sites More sharing options...
Eagle Posted October 12, 2009 Share Posted October 12, 2009 I just checked the temp gauge per your questions. The truck has been sitting for hours and is completely cold. Turning the ignition switch to the 'run position without starting dropped the needle to the line before the 210 line. It does not drop to the left (100). Disconnecting the wire at the sender does not do anything - the needle stays at the line before the 210 line. Grounding the wire to the block or head makes the gauge needle move all the way to the right WAAAAY past 260. Almost to the small screw in the gauge before the wire was removed from ground. I diddnt want to fry the gauge. I fear your temp gauge is FUBAR. The sensor range is 0 to 88 ohms. 0 ohms is zero resistance, which equates to a short circuit -- grounding the wire directly to the block. With the wire disconnected, the needle should peg to one side, and with the wire grounded the needle SHOULD peg to the opposite side. Link to comment Share on other sites More sharing options...
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