Filter light issue

[WarlordArby]

I have a 1987 BJ73 with the 3B diesel.

Was driving home and suddenly the filter light and battery light appeared.

Did some forum searching and seemed like the issue was most likely related to the fuel filter. My filter is less than a year old with probably less than 2,000 miles on it, so I assumed this would be related to the water sedimenter / separator.

I drained the fuel out from the drain on the bottom of the fuel filter, then drove for 15 minutes. Both lights stayed on and it appeared the battery meter was reading a little lower than usual. But the truck actually drove a bit better than before.

Then, I drained it again and same thing, lights stayed on.

So I disconnected the batteries for a few days, came back to it and light was still on. Did one more drain, only this time, I removed the water separator completely, cleaned it, and cleaned the sensor below.

I checked the nearby fuses and they looked good as well.

Any other ideas of what I should look at? I can't imagine there is any water in the filter now. I have drained it three times completely.

 

[duncanrm]

Have you confirmed the alternator is charging.. on the HJ47 at least, this filter light does dual duty as a charging warning light.

 

[sodafeld1]

my filter light can go on if I have water on the electricals, when it dries, it goes off. fwiw.

sometimes the gauges and sensors are more things to worry about than worth. heard a story of a c class merc wouldn't start, towed to merc workshop, it needed window washer fluid topped up to start!

sounds like your filter is ok, if it runs funny then something maybe wrong with your filter and or fuel.

 

[AirheadNut]

The fact that the battery light is on in addition to the filter light is a strong indication that the alternator or voltage regulator (don’t remember if the BJ73 is internally or externally regulated) is suspect. Toyotas of this vintage tend to light up multiple, sometimes unrelated warning lights when there is a charging issue.