Perplexing "FUEL" light malfunction

[Dave WM]

is that a 4700 or a 270000K guessing 4700 gold tolerance band?

Edited August 3, 2020 by Dave WM

[dmorales-bello]

The zcardepot spare part should still have its color code.  Might be good to know.

I'm sure it does but if I take it apart I'm not going to be able to return it.

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[Zed Head]

1 minute ago, dmorales-bello said:

I'm sure it does but if I take it apart I'm not going to be able to return it.
 

Just put it back together when you're done.  Tug that plastic piece out, take a look, put it back in.  Are they/Is he going to resell a part that doesn't work?  

You could ask him.  He might even be following this thread to find a solution.  It's just one guy.

I just wanna see what's in there...

[SteveJ]

1 hour ago, Dave WM said:

I am guessing anything in the 3000 ohm (tested and works) to 1000 ohm (prob just come on faster) NTC small thermistor would work. The one shown in the pic is prob about 4mm in diamenter and about 1mm wide. You can see the relative size to the canister it fits in. I suspect you want something of the same approximate physical size, not only to insure fitment but maybe it is a way to get somewhere in the correct power/heat/ resistance curve properties as well.

I found a forum thread for Honda motorcycles where someone was replacing a thermistor. (https://www.electronicspoint.com/forums/threads/thermistor-in-a-gas-tank.123318/) The suggested replacement thermistor is from Amphenol, RL2004-582-97-T10. That part does not come up, but this one does: RL2004-582-97-D1. It's only 1K Ohm.

[Dave WM]

https://www.onlinecomponents.com/amphenol-advanced-sensor-thermometrics/rl200458297d1-51201820.html

 

seems like pretty inexpensive, shipping eats you up.

 

[Dave WM]

geez

https://www.aliexpress.com/item/32725198406.html

fuel level sensor thermistor will get a ton of stuff.

Not a big fan of sticking hot electrical items made in china into my gas tank, but I guess even the raw thermistors are MIC as well so guess you have to risk it.

 

Edited August 3, 2020 by Dave WM

[Zed Head]

I would bet that zcardepot sourced that thermistor from a modern vehicle.  Maybe one with resistance in line.  Probably gave it a short time frame test and went to market with it.

Might be fun to go to the wrecking yard and tear up some fuel tanks.

[Yarb]

Might be jumping in late. My new ZCD ohms out at 1.8k. The original, I have no idea if it worked when removed measures open so that’s not a lot of help in comparison other than comparing it to Dr. Dave’s ZCD replacement.

[dmorales-bello]

3 hours ago, Yarb said:

Might be jumping in late. My new ZCD ohms out at 1.8k. The original, I have no idea if it worked when removed measures open so that’s not a lot of help in comparison other than comparing it to Dr. Dave’s ZCD replacement.

That's quite different to my ZCD thermistor which had a cold (room temp) resistance reading of 2.9K Ohms.

[Captain Obvious]

I was thinking the same thing. I wonder if it was just measured at a different temperature, or if ZCD has used multiple different thermistors.

[Captain Obvious]

6 hours ago, Dave WM said:

is that a 4700 or a 270000K guessing 4700 gold tolerance band?

I just grabbed a pic of some random thermistor. I wanted something that had leads on it and a pic that wasn't so big that it filled the page. Don't try to read any engineering into my choice for that pic.

But... It's a 4.7K from Vishay:  https://www.vishay.com/docs/29049/ntcle100.pdf

[dmorales-bello]

1 minute ago, Captain Obvious said:

I was thinking the same thing. I wonder if it was just measured at a different temperature, or if ZCD has used multiple different thermistors.

I measured mine on the workbench at a temperature of 74° F.