Water temp and oil pressure guages dead (1 Viewer)

[PA80]

All-
97 HZJ80, 1FZ. No CEL, but water temp and oil pressure guages are dead. I've read the tech threads on them both, but again, no CEL. Should I bother? Is the water temp being dead keeping me in open loop and just going to dump fuel?

Fluid service this morning, plenty of oil. Radiator is fine, overflow bottle is fine, coolant is at the right level in the rad. Thoughts?

 

[Dave 2000]

mmm so the source voltage uses the same buss wire? check fuse.

Yes, if both gauges have stopped at the same time it will be either the connection at the dashboard binacle, or more likely a burnt PC copper line.

I recently calibrated all my gauges because of an oil pressure reading issue, so the binacle was out a few times, the connectors need a spray with contact cleaner, if you can get the one for usage around food manufacturering machine electronics there is less chance of damage to the plastic PC board.

Regards

Dave

 

[Rifleman]

PA80 Just a suggestion, but when you get this electrical problem fixed You might want to spend a few bucks and get a real water temp gauge that you can trust is telling you what you're actual water temperature is Because the factory water temp gauge is known to be a problem​

Don't trust that factory temp gauge

I installed a Koso water temp gauge a few months back when i installed my new factory radiator. Today i decided to do a little test. So i watched my factory gauge as the water temp started to warm up. At a temp of 135 degrees showing on my Koso water temp gauge, my factory water temp gauge...

forum.ih8mud.com

https://www.denniskirk.com/koso-north-america/super-slim-temperature-gauge-ba024b11.p408822.prd/408822.sku?cid=179236

 

[Dave 2000]

PA80 Just a suggestion, but when you get this electrical problem fixed You might want to spend a few bucks and get a real water temp gauge that you can trust is telling you what you're actual water temperature is Because the factory water temp gauge is known to be a problem​

Don't trust that factory temp gauge

I installed a Koso water temp gauge a few months back when i installed my new factory radiator. Today i decided to do a little test. So i watched my factory gauge as the water temp started to warm up. At a temp of 135 degrees showing on my Koso water temp gauge, my factory water temp gauge...

forum.ih8mud.com

https://www.denniskirk.com/koso-north-america/super-slim-temperature-gauge-ba024b11.p408822.prd/408822.sku?cid=179236

I agree, the problem with the temp gauge is built in by Toyota, the early models were quite accurate until the engine temperature reached just a little too high, it would then show (incorrectly) that the engine was overheating, in fact the owners handbook actually shows the needle just below the red as being ok! But to stop customers running to the dealerships about their apparently overheating engines around mid 93 the gauges was modified to hold just below midway or thereabouts pretty much regardless of engine temperature, but being held there whilst keeping customers happy it gave little warning of a genuine overheating situation until it was too late.

Years back I think it was @RavenTai (I think no longer on MUD?) came up with a solution, a couple of resistors removed and others substituted on the rear of the temperature gauge allowed it to display the real temperature of the engine. I myself did the modification when switching to an all electric engine cooling fan, tests with decent measuring equipment showed he got the resistor calculations spot on, the modification still working correctly on my 80 some ten or eleven years later.

The oil pressure gauge also often gets slaughtered, but that is because lack of knowledge about how it works, they are actually quite easy to calibrate and show the correct reading without going out and spending your hard earned cash.

Regards

Dave.

 

[Irish Reiver]

The oil pressure gauge also often gets slaughtered, but that is because lack of knowledge about how it works, they are actually quite easy to calibrate and show the correct reading without going out and spending your hard earned cash.

Hi Dave, I have seen a lot of write ups about the temp guage modification but i have seen nothing about how to calibrate the Oil Pressure guage. Do you have a link or a write up you can share?

 

[Dave 2000]

Dave, are you a landed American Expat in Spain? I monitor global land and sea surface temperatures and Spain is on the edge of some really high temperatures! I really feel sorry for the people in Morocco and Algeria temps of 50C and higher is just insane! Stay safe! have lots of ice water in your vehicle!

Hi and no, I immigrated to Spain from the UK around 17 years ago, I live on the South coast just a couple of minutes from the sea and sand. And yes incredible high temperatures in the Murcia province, we get the extreme temperatures from Morocco as we get their high winds often along with a sticky red sand that when it lands it well...sticks! Presently on 'Yellow Alert' we expect to move to 'Orange' within the next couple of days, already Spain has seen a number of people die from heatstroke and no signs of the heat letting up much before mid September.

Anyone planning a visit to a hot country, contrary to popular belief, your blood does not get thinner when it gets hot, the reverse is true, as you dehydrate water is drawn from your blood thickening it, the result is strokes and heart failure.

Despite only getting my driving licence back in the last four weeks after nearly two years, I have only been going out in the morning in the 80 although the AC just packed up anyway. A little after midday I am indoors with the house AC on.

You mentioning about keeping water in the car is well founded, it is pretty common here to carry water in a cold bag in your car, seeing a motorist broken down I always stop and check if they have their phone and have reached their insurance company and a 'grua' (breakdown truck) is on its way, and of course hand them a bottle of cold water if they had none.

Thanks for the thought.

Regards

Dave

 

[Dave 2000]

Hi Dave, I have seen a lot of write ups about the temp guage modification but i have seen nothing about how to calibrate the Oil Pressure guage. Do you have a link or a write up you can share?

Hi and sure, it is in my long running build thread, link in signature. You will need to search it out, the search function linking to my username should help you. I need to stay off the 'net' for awhile, not too good for the headaches!

Regards

Dave.

 

[Irish Reiver]

Thanks Dave. I was being lazy in the hope that you had something "oven ready" . I will check out your thread when i get back home. Currently in Arizona working in 44c temps with no AC . I feel your pain. Stay hydrated

 

[Dave 2000]

You lazy git!

See post 228 in my thread.

Regards

Dave.

 

[PA80]

PA80 Just a suggestion, but when you get this electrical problem fixed You might want to spend a few bucks and get a real water temp gauge that you can trust is telling you what you're actual water temperature is Because the factory water temp gauge is known to be a problem​

Don't trust that factory temp gauge

I installed a Koso water temp gauge a few months back when i installed my new factory radiator. Today i decided to do a little test. So i watched my factory gauge as the water temp started to warm up. At a temp of 135 degrees showing on my Koso water temp gauge, my factory water temp gauge...

forum.ih8mud.com

https://www.denniskirk.com/koso-north-america/super-slim-temperature-gauge-ba024b11.p408822.prd/408822.sku?cid=179236

Oil pressure turned out to be a rusted out ground on the also rusted out sending unit. Replaced it and patched the wiring harness and it's reading accurately. Jury is still out on water temp.

 

[Rifleman]

So how long have you been a resident in Arizona? Do you recall 10-20-30 years ago being this hot this long in the past?

I think i might be qualify to answer this question, as being a resident of Arizona since 1964, and in particular the city of Phoenix for 52 years, Why yes, i can remember it being this hot 10, 20, 30 years ago, since we live in a desert we even have a name for this condition, it's called summer time,

Oh one more thing, the official temperature readings that the national weather service reports for the city of Phoenix are taken at Sky Harbor international airport, That temperature gauge is surrounded by miles of hot asphalt and is blasted with jet exhaust, i know this for a fact because i use to have my airplane based at Sky Harbor airport,

 

[Rifleman]

All national city tempatures are obtained from airports. So this time around, its lasting much longer then past heat waves. Also, I belive on a global scale, the Hadley cells are migrating north towards the poles that is a BIG deal but...its a very slow progression.

Seeing as this topic is far removed from PA80 temp and oil pressure gauge's not working, and is not a topic for a tech forum, lets move this conversation back to a tech topic

 

[BILT4ME]

All-
97 HZJ80, 1FZ. No CEL, but water temp and oil pressure guages are dead. I've read the tech threads on them both, but again, no CEL. Should I bother? Is the water temp being dead keeping me in open loop and just going to dump fuel?

Fluid service this morning, plenty of oil. Radiator is fine, overflow bottle is fine, coolant is at the right level in the rad. Thoughts?

You mention a HZJ80 with a 1FZ.

Is this a typo? Typically, anything with an H is a diesel.....

 

[BILT4ME]

Aircraft have redundant and some times, back up gauges. might be a good idea to have redundancy.

What the Fuuck does this have to do with this comment? STFU and stick to your Global Warming thread.

 

[Rifleman]

Yes, it is a important issue. Another American died in his car in a remote us park. He was driving in temperatures of 115 F. His car broke down, and he had no way to call for help out of cell range and died from heat stoke. Oh and btw, the global heat waves are going to be larger, last longer then current heat waves!

Just a FYI, if you keep going off topic with all this climate change stuff in Mud's tech section, Mud's moderators may start deleting all those non tech based posts