93-97 Coolant Temperature Gauge Modification (3 Viewers)

[Stevesnj]

I want to do this mod but just look at the OP and has anything changed regarding doing this mod? I don't feel like going through 23 pages of posts and come to find out the resistors were the wrong rating. So my question is can I still go by the OP for the correct procedure and parts acquisition?

thanks

Steve

 

[Rookie2]

I did the mod years ago following RT's original directions and it's worked great ever since. I think some folks played with the design a little, because they wanted the gauge to hit red at a higher temp. Other than that, I haven't kept up with the thread over the last couple years.

 

[semlin]

the original procedure works fine and there are no meaningful tweaks afaik. my 93/94 prototype still functions flawlessly.

 

[Dave 2000]

Dave-You sure about that? Engine driven fans have a rep for being far more reliable and moving far more air than electrics. I'd stay with the VC and the fan, but let us know what you come up with.

I think like most technologies things have moved on, twin electric should be OK and I am pretty sure the diesels run a lot cooler than the petrol versions. I did this on my Land Rover Discovery but with one fan and it was brilliant, apart from hardly ever coming on when it was needed it was great, also made crossing deepish water a cinch as well as you could switch it off.

I will let you know how I get on,

regards

Dave

 

[Dave 2000]

the original procedure works fine and there are no meaningful tweaks afaik. my 93/94 prototype still functions flawlessly.

I did spend the time reading through before I went for it, as I was IIRC one of the first with a diesel engine it was a suck it and see project, it works brilliant and IMO one of the best bang for buck mods you will ever do to your 80.

regards

Dave

 

[RavenTai]

I want to do this mod but just look at the OP and has anything changed regarding doing this mod? I don't feel like going through 23 pages of posts and come to find out the resistors were the wrong rating. So my question is can I still go by the OP for the correct procedure and parts acquisition?

thanks

Steve

The modification is still the same, if it had changed I would have changed the first post, I consider the resulting gauge responsive, some find it overly sensetive, especially those who find out post mod that their truck has been running hot. There are a few other resister mixes with the goal of a less sensetive gauge,you can read about those in this 23 page thread, but the stock mod has not changed.

 

[Stevesnj]

Thanks all!

 

[Stevesnj]

So I am probably the only one that messed this up. When I started to solder the 110 ohm resistor the leg at the egde of the board but the copper circuit on the board delimited from the board. The resistor is soldered to the copper fine the copper just separated from the board. The resistor reads 73.6 on each leg closest to the resistor itself. The 50 ohm went on no prob and reads 42.5. I attached a pic of my screw up.

Is this ruined? Do i need to get another cluster?

 

[JohnR]

The trace is still good. I'd push the leg all the way in to lay the trace back on the board, and use some sort of adhesive on the resistor/leg to hold it in place. Maybe even a drop of superglue around the solder joint to keep it laying down. All is still well.

 

[Stevesnj]

The trace is still good. I'd push the leg all the way in to lay the trace back on the board, and use some sort of adhesive on the resistor/leg to hold it in place. Maybe even a drop of superglue around the solder joint to keep it laying down. All is still well.

Okay sounds good, this is my first time de-soldering and soldering a resistor. I have some epoxy, I think that should work.

 

[azTony]

I do not remember but is this a double sided board or single? If it is double (pad on top and bottom) I would pull it through and solder to the pad on the opposite side first. I am thinking it is a single sided since it lifted like that. Just thought I would mention it.

 

[Stevesnj]

I do not remember but is this a double sided board or single? If it is double (pad on top and bottom) I would pull it through and solder to the pad on the opposite side first. I am thinking it is a single sided since it lifted like that. Just thought I would mention it.

Yeh single sided

 

[hakalugi]

how appropriate to find this thread.

it was over 90 degrees, and i'm towing a trailer for the first time with my 80 and i think: "man, that temp gauge just doesn't seem to move... wonder if it's working"

so from this thread i've learned:

1) there is circuitry in place to stabilize the needle to the mid point if it's within a 'range', yes?

2) there's this mod that will make the needle track more closely the actual relative temperature variations.

i like the idea of a more accurate needle, but has anyone else thought about leaving the stock temp gauge, stock, and adding a 2nd temp sensor to another locaiton in the coolant path and a a digital readout in the cabin?

am I a heretic?

 

[CycloSteve]

i like the idea of a more accurate needle, but has anyone else thought about leaving the stock temp gauge, stock, and adding a 2nd temp sensor to another locaiton in the coolant path and a a digital readout in the cabin?

am I a heretic?

Plenty of folks do this by leaving their OEM gauge alone and monitoring the real temps via either a Scangauge or other external aftermarket water temp gauge.



Steve

P.S. So far I just went with modding the gauge. It is easy and works excellent; took 30 minutes and less than $5 to accomplish.

 

[BirfMark]

i like the idea of a more accurate needle, but has anyone else thought about leaving the stock temp gauge, stock, and adding a 2nd temp sensor to another locaiton in the coolant path and a a digital readout in the cabin?

am I a heretic?

Not at all - I didn't see the benefit of making the gauge more 'accurate' like this thread shows, because you still don't really know what temperature the engine is running at. Sure, the gauge will move more, but without any numbers to indicate where the needle is pointing, what good does it do?

I installed a set of digital gauges in mine, so at a quick glance, I can see exactly what the engine is doing. My install thread is here: Gauge Install. Maybe it will give you some ideas.

 

[Dave 2000]

Not at all - I didn't see the benefit of making the gauge more 'accurate' like this thread shows, because you still don't really know what temperature the engine is running at. Sure, the gauge will move more, but without any numbers to indicate where the needle is pointing, what good does it do?

I installed a set of digital gauges in mine, so at a quick glance, I can see exactly what the engine is doing. My install thread is here: Gauge Install. Maybe it will give you some ideas.

I like to have a less cluttered dashboard and to fit an aftermarket gauge duplicating an OE fitment I could not see the point. Whilst it is true if you use your car in competition then changes in running temperature of say 10 degrees may be of concern but in a DD this is not really an issue. Minor temperature changes of the OE fitment should be of no concern hence the reason for the gauge being 'damped' by Toyota. After modifying the OE fitment with this mod I can monitor the gauge under conditions that MAY cause concern, the long haul up a steep hill whilst towing ect, when driving our vehicles we get to 'know' where the needle 'sits', any variation might be worthy of a secondary glance, if I saw my temp gauge pass the 3/4 mark I would pull over because this is not the 'norm'. It is true if I could modify the OE gauge with accurate temp readings along with the oil pressure/volts/ect from accurate sensors (not always the case in my experience) I would but in a DD IMHO not needed. Still I liked the thread about the gauges install, as they are out of your 'line of sight' do you refer to them often or have a 'buzzer' to draw attention to the fact that there may be a high temp situation?

regards

Dave

 

[atomicshawn]

I wish I had this done prior to heating issues last year. A very cool mod. Another testiment to the utility of this forum and the remarkable knowledge and ability of those that contribute. Thanks again.

 

[tonyteb]

FYI

Australian Supplier for the 2 resistors

Wirewound Resistors - Through Hole 3watts 110ohms 1%
RS02B110R0FB12
http://www.x-on.com.au/details-new.asp?i=1092909&t=1&p=RS02B110R0FB12

Wirewound Resistors - Through Hole 3watts 50ohms 1%
RS02B50R00FB12
RS02B50R00FB12 - Price from: $1.07 | Vishay/Dale | Passive Components | Resistors | Through Hole Resistors | Wirewound Resistors

 

[TomH]

Anyone had this mod go bad?

I did the mod about a year ago and it was working fine until a few months ago. Still getting needle movement but it's in the lower 1/3 of the gauge. I figured the cheap aftermarket thermostat I put in last year was stuck open so I just replaced it today with OEM. Same results.

Now I'm suspecting one of the resistors failed or a bad solder joint. Any other thoughts?

Thanks
Tom

 

[Dave 2000]

Sound like a faulty joint, for quickness I would dab the joints with a hot iron and re-solder. Having said that the work involved in pulling the dash it might be just as easy to solder in two new components? Before doing any of that disconnect the wire from the temperature sensor and ground it, if the gauge goes straight to hot (ignition on) then the sensor is at fault, if your temp sender has two wires then simply bridge them with a paper clip and again with the ignition on look for the gauge going to hot. If the gauge rises slightly as you mention then I would pull the dash and check the connections ect. Faulty gauges are rarely the problem, it is normally the connections/sensor or of course any mods gone wrong. Mine has only been done a few months and works fine but I have had some experience in soldering and would not be too happy if I made a bad joint that failed in year or so!

I hope that helps, no doubt others will chip in with longer term installs that mine.

regards

Dave