installing gauges

[Kenbob]

My 89 I just bought has the basic dash with idiot lights. I have seen some gauge clusters cheap enough, but it is my understanding, I would need new sending units for oil and water. Am I right on that? For about $35 I can get some mechanical mini gauges that I think would mount just to the right of the very left a/c dash vent. It would seem I could have mechanical gauges for the same money as factory electric......any landmines in that? any opinions?

[mule13]

i think this falls under personal preference. if i have electical gauges i usually install mechanical gauges anyway.I'm old school i guess and don't trust electronics to much lol.

[Kenbob]

That is how I feel. I like to see that temp gauge go up and then fall back when the thermostat opens. Have you installed mechanicals on the 4.0? Any problems?

[mule13]

i havent yet, the gauge in my comanche seems to work fine actually. it goes up to about 210 then drops down to 190 back and forth while i drive.i'm still working on other "problem areas" for now eventually i'll instal mech oil psi and temp gauges though. before summer for sure.

[91coMANche]

I just did the factory upgrade and don't regret it. The electronics are failproof because remember that they are simply measuring resistance/ground (take off the oil pressure sender wire and ground it and the gauge goes one way and then remove the wire from ground and it goes the other way). The gauge are indeed active and move. You will need to get a different oil pressure sending unit but I believe the temperature sender in your head should work. I will wait for someone else to chime in on whether that is correct (pretty sure the gauge and idiot light sender for water temperature is the same).

 

Plus going factory will just look cleaner and honestly won't cost much if anything more.

[jimoshel]

For idiot lights the sending units are switches. For gauges they are variable resistors.

[91coMANche]

For idiot lights the sending units are switches. For gauges they are variable resistors.

 

You are right, I just looked it up but you beat me to it! The sending unit for coolant and oil pressure are simple to install and cheap enough so its a nice upgrade in most cases.

[jimoshel]

I prefer the gauges and usually when I get something with lights I install aftermarket gauges. With Jeep just swap instrument panel. If possible I like to leave the oil light so if I'm not paying attention that sudden red gets it. On some motors you can tap into the oil gallery and add the extra sending unit. Otherwise get a tee fitting and use the original location.

[Kenbob]

Ok, I appreciate all comments and I read all posts about this from previous. After reading those I am still fuzzy about two things: I get the impression the wiring for the tach is there even if I don't have one now. Is that right? If I find a cluster without a tach does it matter if it is from a 2.5 or 4.0. From the posts it sounds like the calibration of the tach was the thing that made the switch a no-no

[91coMANche]

All wiring is present. Not sure about 2.5 so just avoid those until finding out.