cluster swap sender questions

New guy here,

I officially joined the XJ Brigade about 3-1/2 weeks ago by purchasing a '91. My lift kit is sitting in my living room, -and tires/wheels should be here this week. This weekend is lift weekend, -I can't wait.

This is my first post, -but I have been reading here for a while, -(and yes, using the SEARCH and FAQ features!)

Here's my deal, my '91 was a stripper with no gauges, -so off to the wrecking yard to get a cluster and senders I went. I got a cluster out of a '92 and was able to get the OPS out of the same rig I got the cluster out of. I wasn't able to get the temp sender because someone already had a go at removing it and busted it off. I ordered a temp sender from the local auto parts store for a '92. So, I install the sender, -but notice that no coolant comes from the hole when I remove the old temp switch???? I also notice the new temp sender has a weatherproof plug socket on it, -whereas the one I took out has a 10-32 stud???? I figured no biggie and dremeled the plastic portion off the plug so I could plug a standard blade connector onto it.

Everything installed and wired, and the temp gauge doesn't work. I have checked to be sure the sender is grounded to the engine, -and I have verified that the gauge circuit is good by grounding the sender wire (the end that plugs onto the sender), -and it pegged the temp gauge. I would assume that this means the circuit from the gauge cluster to the engine compartment is working ok???

What is the likelyhood that I got a bunk sender?

Here's something else that I find interesting, -1991 supposedly calls for a different temp sender p/n than the rest of the years.

At Rockauto's website, they call out a TS-199 for 1991, and a TS-334 for '92 and up. The one I have is a TS-334, because I assumed I was matching it to the gauge cluster, -not the vehicle. Maybe there's something peculiar in the harness of the '91?? Maybe there is a huge air pocket or blockage in my cooling system? -Why did no coolant come out, -even with the system vented?? -Regardless, -the temp sender would still get warmer than 100F, -especially since it is located so close to the exhaust port back there.

I am tempted to order up the TS-199 and give it a shot, -the problem is, -the one I have butchered the plug off of is not returnable, -dangit.

Thoughts and ideas welcome,

I am baffled on this one........

Thanks in advance.
Rich

You replaced the temp sensor closest to the firewall (not the thermostat housing) with a sending unit for the gauge and not dummy lights right?? (I am just making sure you did the correct sending unit, because this is the only thing i can think of that would go wrong.)

88XJSport said:

You replaced the temp sensor closest to the firewall (not the thermostat housing) with a sending unit for the gauge and not dummy lights right?? (I am just making sure you did the correct sending unit, because this is the only thing i can think of that would go wrong.)

Click to expand...

Yep, -the sender is for the gauge (according to the standard ignition part number), -and the port I used was the one back next to the firewall on the cyl head.

Believe me, -I had concerns that the parts guy may have sold me the temp sender for the ECM, -but I checked and the ECM temp sensor is 1/2" NPT, -and the gauge temp sender is 1/8" NPT, -so there's no way I coulda fubarred that.

I spoke with a friend today who is in the auto repair business. He told me that when Chrysler first nabbed AMC, there were many "on the fly" changes that were made to wiring, etc. He also told me that there are in fact two different temp senders for the electronic gauge clusters, -and guess when the transition year was? -mid 1991!!

SO, I have two brand new senders (one of each type to rule out if the one I have now is bad). I am going to give it another go tonight to see if the "rare but special" sender makes the gauge work.

If the special sender makes it work, -maybe the sticky should be updated so that others don't go through the same thing.

I'll post the results.

Thanks for your help and response, I appreciate it,

Rich.

Well, the verdict is in. The early-style temp sender made the gauge work on my '91.

So, what this means is that anyone with a '91 that is doing an instrument cluster swap over to gauges have two potential temp senders to choose from, -but only one will make the gauge work. The later style (Standard Motor Products p/n TS-334, or Borg Warner p/n WT-430) would not make the gauge work with my '91 harness. Installing the earlier style (Standard Motor Products p/n TS-199, or Borg Warner p/n WT-398) made the gauge work perfectly.

The early style can be identified as having a 10-32 stud for the electrical connection, whereas the later style can be identified as having a plug receptacle with a blade connector inside the plug.

I was a little baffled, because the early style sender looks almost EXACTLY like the idiot-light switch that it is replacing. However, there is a slight difference in the length of the snout where it goes into the head. The sender has a slightly longer snout compared to the switch.

Thanks for taking the time to come back and give us the answer.




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