hask

Hello,

I have LS400 1992, the temprature guate is in accurate, we've change the radator, water pump, thermostat, but it seems that the temprature guage is inaccurate, at the same time, we've repare the cluster lighting, so form that time, since we replace from old cluster to the current one (some lights), from that time the temprature reading its seems inaccurate.

any one could suggest me the capacitator that I might change to fix the problem?

Many thanks

LScowboyLS

capacitors don't control the accuracy of the temperature gauge, the gauge sensor does

the gauge sensor is a single wire sensor near the passenger side coil, right next to the 2 wire Engine Coolant Temperature Sensor (the one for the ECU)

I would change both of them, as the second one will likely make the car run much nicer, on both of these, use the real Toyota part

hask

Thanks, but could you please clarify because I did not understand where they are locate, I should be grateful if there is photos explained the mentioned parts.


Many thanks.

Rasimmo

Both gauges are behind the top coil pack, the 2 wire sensor is for the ecu and the 1 wire sensor(smaller one) is for the gauge. I had this same issue.. I took the cluster apart and found out that the temp gauge itself was broke..literally..the shaft between the needle and the motor was cracked. I'd assume it was from hitting the dash to get the tach/speedo to work. So if you have to hit the dash sometime..I'd check that out


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hask

Yes, actually my brother repairing it, and he said its very hard and easily could be broke, but as I understand the coil is on the cluster it self from the back?

Thanks

Rasimmo

I apologize..I meant to say "both sensors are behind the top ignition coil" the one on the engine.. my bad.. Hope this helps

LScowboyLS

nice pic! - I am stealing it! - lol

hask

Thank you guys, I will till him and I will keep you updated with the findings.

LScowboyLS

you can test the gauge (single wire) sensor circuit (which consists of the gauge + the wiring between the sensor and the gauge) by unplugging the connector and that should produce one extreme on the gauge with ignition in run position, and then jumper the connector to ground and that should produce the other gauge extreme (I forget which is which, but one will be full hot and one full cold)

Rasimmo

have at it

Yamae

Reading above part, I worry about that the replacement might be effecting the inaccuracy.
Did you remove the negative terminal of the battery when you replaced?

The connection and the disconnection of the connectors without removing one battery terminal may cause the damage to the devices since 12V is always supplied to the cluster, some unexpected DC supply would cause problems.

hask

:Correct, but the cluster unit its removed from the car while reparing it

LScowboyLS

post a very high resolution photo of the circuit boards on the back of the cluster, and yamae and I will repost the photo with the through-hole electrolytic capacitors circled, which are the ones that need to be replaced.

then you can post the numbers off of them and I will provide links to which ones are the premium replacements with the proper low-ESR etc.

sanstoette

Looking at that sensor... how accurate are they on the LS? My Nissan gauge sensor was only 3 position... cold, normal, and screwed.