New sensors

[Warren99]

So I was at the local gray and white looking for a new AC line and found one, but got stung by a wasp while trying to get it so I abandoned it. But I just so happened to FINALLY find a cable speedometer gauge cluster with actual gauges instead of idiot lights. Its my understanding that I need to get new sensors for the oil and coolant gauge, maybe the battery voltage too, and I can just order them new instead of trying to find some on a Cherokee. Are they at oreilys, rock auto? I haven't even looked yet but I don't know what they would technically be called.

 

Also, not important but just curious, after I turn the truck off the tach just stays at 900 or 1000, whatever it was idling at. Even when I turn the power on, other gauges react but the tach doesn't shoot to 0. Is is messed up or just how it is? It seems like it works fine, but I've literally only driven it once with the new cluster. It does kind of seem like it might be a few hundred rpms high at some points, which is why I'm even mentioning any of this. Let me know anything it might be. 

 

-Thanks!

[jdog]

Oil pressure sensor w/ gauge

Coolant temp sensor w/gauge

That tac looks like the needle is in the wrong spot, it is supposed to go to zero

[scaleless]

I personally recommend WVE 1T1160 for the coolant sensor and WVE 1S6563 for the oil sensor.  As for the tach, jdog is right - the guage can easily get get jostled into the wrong position, especially when it's being removed the truck.  To reset it all you have to do is take the face off the guage cluster and push it back to 0rpm.  It should operate normally after that.

[eaglescout526]

Go Mopar for the oil sensor!!

[Warren99]

Thanks for the help. And the tach just being off makes sense, I had the cover off and cleaned it up before I put it in, and I'm pretty sure I moved it, so I'll just put it back to zero.

[ghetdjc320]

Go Mopar for all available sensors if you want decently accurate gauges lol. Does the rpm read accurately when running or is it always off by a bit? 

[Warren99]

I'm not sure. At idle it slowly fluctuates between 1000 and 1250. And when I turn it off it goes down to what I'm assuming is just above 750. Pictures shown are idle followed by shut off.

[Warren99]

10 hours ago, eaglescout526 said:

Go Mopar for the oil sensor!!

I looked on their website and all I see are sensors for newer jeeps and other mopar brands, I can't find one for anything with a 4.0, or really anything from before 2000. And most of them are like $40, while the one on rock auto is $10. Are the ones from rock auto known to be crap or anything?

[eaglescout526]

I mean aftermarket is a crap shoot in general. Here is the newest number for the sensor: 56026782AC. Shoot me a PM and I can get you one for about $25 from Chrysler if you would like to go that route. 

[scaleless]

While I wholly agree that aftermarket is a crapshoot, I have had very good and continuing success with WVE (and their parent/sister divisions NTK and NGK).  One of my Cherokees has WVE sensors and they seem very accurate, which is why I personally recommended the WVE sensors.

[Warren99]

Alr thanks, I'll just get those.

[Warren99]

While I'm here talking about sensors, what is this? I'd assume another oil sensor since its right on or above the oil pan. The connector is dangling there, the retaining clip is broken so it doesn't stay on. I'm just asking because I have no idea if its important at all. I might ziptie or duct tape it on eventually, unless it actually is important then I might get a new connector.

[scaleless]

That's the knock sensor.  It would retard the engine timing if it was knocking.  If your engine is otherwise fine, leaving it dangling doesn't hurt anything.  It uses the same EV1 connector as the fuel injectors, so if you find a Cherokee in a junkyard you can just steal the clip.  Or buy some pigtails on Ebay.

 

They're not cheap, butbif you need one they are still available new:

https://www.rockauto.com/en/moreinfo.php?pk=10060028&cc=1181483

[Warren99]

Alr thanks

 

[Minuit]

I got bitten by the aftermarket senders - more specifically, Wells, once. Never again. Made me chase my tail on an "overheating" issue for slightly longer than I'm willing to admit. Mopar for everything for me from now on.

 

With properly cleaned connections (this is CRITICAL on a resistance-to-ground type sender such as we have on our trucks) and the proper senders, the dash gauges are trustworthy.

[Warren99]

My radiator is from a 96 cherokee. I think the sensor has a little connector thing wired to it, do I need to get that too? Years ago after I put the radiator and the fan in from that XJ, I noticed the wire hanging and the same connecter right there on the fan so I just left them connected. No clue if the fan even works or is wired to work in an 89 MJ. Regardless, just get the same style sensor some of yall have linked part numbers for in the chat, or should I get the wire? (shows both kind under 89 MJ on rock auto)

[scaleless]

I'm fairly confident - and someone will correct me if I'm wrong - that the connector in the radiator with the wires coming out are solely used for the engine computer's calculations, and the guage is driven by a sensor on the rear driver's side corner of the engine head.

[scaleless]

Here, specifically

[Minuit]

16 minutes ago, scaleless said:

I'm fairly confident - and someone will correct me if I'm wrong - that the connector in the radiator with the wires coming out are solely used for the engine computer's calculations, and the guage sensor is driven by a sensor on the rear driver's side corner of the engine head.

Close - the radiator one is a switch for the auxiliary fan (Renix only - that became an ECU function on HO models), the rear of the head is for the gauge, and the sensor for the ECU is in the side of the block for Renix and thermostat housing for HO.

 

At some point after I believe either 96 or 97, the gauge reading was supplied from the ECU instead of the sensor in the rear of the head, so then there was only one coolant temperature sensor.

[Warren99]

Oh ok thanks for clarifying, ordering them rn.