LCD temp readout...
 

Hey, well, I have a 92 benz... a w124 300E. It has an lcd temp readout in the middle of the guages. The problem is, at under 65 degrees (outside temp) the screen goes blank. Is there a reason for this? I have been reading about faulty temp probes... what kind of probe would I replace it with? Thanks.

Hmmm mines is blank most of the time for me I was told that I need the whole lcd component in the dash $ 225.00 used I dont know about the probe that you asking about but on my car the sensor sits between the bumper and the radiator

i have a 93 - mine is on right now but when it was hot it faded in and out and would be completely out at times. right now it's working and nothing seems to be wrong with it. not replacing a $200(?) part on account of that...

The probe wouldn't cause a screen blackout, it most likely is the LCD head...yep around $200/$250...unless you can find a second hand cluster and use that.

Hmm... well.. the screen doesn't black-out... its just goes blank. Kinda as if it just turns off. Im pretty sure its not the lcd unit, because the unit always works above 65 degrees. So, I think im gonna replace the temp. diode. Now, could anyone tell me what type to get? I mean, is there a certain resitance I need? Anything like that. I think im actually going to rig it so I have several temp. diodes hooked up at the same time, and just wire them through a rotary dial, so then I can pick which temp. diode I want the screen to readout. But yea, type of diode to get would be greatly appreciated, thanks!

LCD
 

I have one from a 88 420SEL, any offer?

Hmm... well I was hoping I could just pick it up at radioshack or Fry's... I mean... im gonna need like 6....

Hmmm... guys... anyone know what kinda thermal probe to buy? Anyone? Anyone? Will the radioshack variety work? Come on now... somebody has got to know....

Ask Phil in PartsShop!!

There are a couple of excellent threads on this topic. There is a fairly simple test noted in one of the following discussions for determining if the problem is due to the display or the temperature probe or thermistor, which is located under the front license of the (at least) the early 90s versions of the W124 cars.

I replaced the thermistor on my ’92 and it works fine. Should there be an interest, I have 3 of the thermistors. I bought a few at Allied Electronic. I’ll sell them for $7.00

Here are the articles:

http://www.peachparts.com/shopforum/tech-help/14376-outside-temp-lcd.html?highlight=thermistor


http://www.peachparts.com/shopforum/tech-help/7854-87-300e-outside-temp-gage.html?highlight=thermistor






Regards

One of the many reasons this is such an excellent site. I have a 92 300e 124 too. It has the identical problem. Some days the display is working, other days it is not. Haven't been able to notice any trend as of yet. I don't think I would go to all the effort of customizing with diodes but it is an interesting point. I think I will start with the external thermistor. Thank you for posting this thread and to all who have commented.

i wonder if this is related to my wiring harness problem. i don't get erroneous readings. the display just fades in and out sporadically. then it will stay on rock solid at times, which it has since my car has gone into the shop. regardless, i'm getting one of those thermistors..

lebenz, you've got mail!