Gauge Cluster Removal

[EliRush]

Hi all, here is another noob question...and I searched, and looked in the FSM, nada...

I want to remove my gauge cluster, and have removed some other clusters before...but how do I start? I've never seen one removed, does it pop out from the front, or what? I don't see any screws and I don't want to break any 25 year old plastic tabs. Once I get the cover off, I will be fine. I know it has a cable speedo, and to reach up into the dash to pop it free before pulling the cluster all the way out.

My reasons for doing this are related to my other post about "climbing cruise temperature". The temperature only rises when I am using electrical devices, like lights, fan, radio...so I think it might be the gauge itself. I also want to change out the bulbs while I am in there. I have checked wires for the temp sender units, they are fine. I have read other posts on gauge issues, and I am hoping it is just an old wire or bad connection or something. Any tips would be great here.

It is an obvious electrical issue, when you shut off the fan and headlights, it drops down to almost normal, turn them back on and it shoots right back up again. During the daytime I can run it without any lights/radio and it stays in the middle.

Thanks!

[dlb]

the screws for the cluster hood/cover are on the underside of the top of the hood so you have to attack them from below, like a kraken. once you pull the hood off, you can easily see and access the screws holding the cluster in place but you will need a short phillips screw driver because the wind shield makes space tight. then you must unplug all of the wiring and speedometer cable--don't worry about putting them back in, i believe each plug is uniquely shaped so that they can't be mixed up.

it's been a few years since i've taken a dash cluster apart but i think that's it. there were no surprises as i recall.

[EliRush]

Thanks! lol like a kraken

[Highlander]

Eli- Be sure to wait until you have the cover/shroud off before trying to remove the speedo cable end- It's like the electrical connectors where you have to squeeze both sides before you pull it off. If you don't get it right, it'll break one of the clips off and then when it gets cold, the speedoi'll vibrate and jump about. You'll also want to pop the little covers off around the clock set post and the trip odo reset buttons (as well as the buttons) before you move the cluster.

[Petros]

There are four screws, and you can not see them from the driving postion, you have to put your head down low under the dash. Two are at each lower corner of the visor, and two are up in the visor above the face of the instrument cluster.

I do not think you will find that problem in the cluster however. more likely it is a ground issue, or perhaps corrosion in the fuse block. Or possibly a faulty gauge, but it does not make sense that it works normal until you turn something else on.

Consider that there should 12 volts at the gauge, and the sensor wire is just a ground wire. the sensor itself is a variable resistance ground, if you ground the wire directly it makes the gauge go to full hot. So what would make the sensor wire go to full ground when you turn on the other devices? Either the sensor wire is bad, the sensor is bad, or there is stray voltage running around your cluster doing something it should not be doing. have you checked your voltage at the battery? I wonder if you regulator is bad and it is over charging it so something odd like that.

[EliRush]

I've checked some sensor wires, but not tested for voltage. It didn't seem to do it until I did a bunch of work to it...and a lot of what I did could affect it. Radiator replacement (reused old sensor, which was shiny and gold), fixed the front top sensor with a fresh wire to try to fix this temp problem (same gauge wire), and added fog lights that are run from the fuse block through a switch. It seemed to start after I changed the radiator, and before I did the rest. Bottom sensor issue?

Maddening, it is. It drives just fine, and if the temp gets too high and bothers me, I just turn the fan off and it drops. Stopping and starting in traffic, or shutting it off for a few minutes and cranking it back up makes the temp go down, with or without electrical accessories on. I drove it at night, headlights, radio, fan, and was stop and go through intersections...temp was half or just below half the whole time. Take it on the highway for five minutes at 60-65 and it goes right back up. Turn off the fan and drop it down, and then it will be stable at 3/4 until I slow down or stop when it will drop to below half and be fine again.

During the day it will sit at the half cruising, but might get a little towards 3/4 at 60-65 mph up to about 75-80, when it will drop to about 1/3 and stay there until I let my foot off.

Exorcist? The car is totally friendly otherwise.

Thanks for the tips on the screws, I had a total derp moment when i realized I had seen that before. I might put it off if it is the lower sensor. Sorry about posting this same freakin issue in so many places, but you guys are helping me narrow it down, and I really appreciate it!

[Petros]

The temp sensor is the one mounted on the front of the head, next to the timing belt cover. It uses a flat blade connector. the other on the outlet is for emissions controls. These temp senders are usually pretty reliable, but that behavior could either be from limited cooling capacity of the radiator (parcially pulged, needs a heavy duty flush or replacment), a bad thermostat, or a bad sender. Nevery actually heard of a short somewhere else in the system causing it to act that way. Not that it could not happen, just seems very unlikely as outlined above.

You really need to veryfiy that it is a gauge fault or if the temp is really going up and down. You can buy a cheap temp gauge at the autoparts store and run it as test set-up, just to make sure it is electrical and not mechanical. If temp is okay than you can drive if safely, and go find a new sender to test it out. Since the senders are usually pretty reliable, a used one from a wrecking yard is usually a safe bet. I have had only one go bad that I have seen out of a large number of old Tercels that I have owned or worked on.

[EliRush]

For those who are wondering, it was the THERMOSTAT! Stays at 1/3 at any speed now. Very happy!

[dlb]

good stuff. thanks for posting the follow up, it's useful to everyone here and future users to know what symptoms you were having and what the solution was.

[Petros]

good call. Usually the T-stat is the weakest and most unreliable part of the cooling system and should always be suspected (even if fairly new, many are junk out of the box). Next would be build-up in the radiator, bad head gasket, bad cooling fan sensor, and than the sender.

[Lil Beast]

The cooling fan sensor, me I solve the problem with a on/off switch! The part is obsolete in the part stores! Could probably use the one from a newer one but works fine for me, I pretty much have to turn it on if I leave it idling more than 5 min. in the winter and in the hot summer days it's pretty much always on in city driving and off on highway!

[Petros]

better keep a close eye on the temp gauge because it is easy to be distracted from the dash, esps in heavy traffic. It could lead to having to replace the head gasket. Those sensor are pretty reliable, used ones from wrecking yards are a good bet.

[Lil Beast]

I'm not worried at all! It's been like that for well over a year now! I like it, the temp always show close to the C(cold)! There is a light on my switch so I know if it's on or not without looking! Light on, fan on !

[EliRush]

That would be bad for me, I know I would forget to turn it on! I would probably modify a sensor and make it work.