'87 Digital Dash Fuel Gauge Not Working
 

Hi, I'm new to the forum. Just picked up a '87 4Runner SR5 Turbo with 111K miles, 11K since 22R-E rebuild, and 1K on a Marlin W56-B and drove it 13-hrs from TX to AL. Most everything on the truck is factory original, but the PO had put an aftermarket Fuel Gauge (see pic) below the dash which seemed odd. Everything else on the SR5 digital dash works fine, but the Fuel portion just flashes (ALL Lights / NO Lights)

Any ideas on what might have gone wrong and how I can get it back to the original dash and remove the aftermarket gauge - it's in the way of the marine cup holder I want to install :).

Any ideas? What do I need to check? I'm not an expert on fuel pumps and gauges.

The digital gauge cluster is pretty rare so most people here have never messed with them, including me.

My 1987 Factory Service Manual has all of the testing procedures for this cluster.

Digital copies are floating around the internet.

I will have to go look and see what a flashing gauge means. Maybe just no signal?

Obviously the previous owner decided to bypass the problem instead of fixing it.

I would first look at how the aftermarket gauge is hooked up. It is anybody's guess as to what the previous owner did.

That may give you some insight as to what the problem is.

Awesome 4Runner by the way!

:safari:

Most issues I have dealt with on the gas gauge is in the float in the tank. There is a fine wire about the size of a human hair that acts like a resistor that gets worn into two pieces. I have even seen the crust build up on the float assembly so bad that the float can not move.

There is a test that you can do where ground out the connector on the Float Assembly and it will make the Fuel Gauge rise to the maximum. Been a while since I have done that test and cant recall right off the correct steps to do it. I would bet your Float Assembly is bad. I have never worked on the Digital Gauge but still would think it is in the tank.

Do a site search here (site:yotatech.com) on Google for digital dash or digital cluster and fuel gauge or fuel sender. It should turn up the specifics..

Iirc the digital dash uses a reverse voltage from the standard.

Likely someone couldn't find or didn't want to pay for the other fuel level sender and put in a random one toyota one and the aftermarket gauge.

The digital one could be loose or disconnected also.

Great, thanks everyone. I'll start searching and let everyone know what I find out!

Repairable
 

So my son has an 87 turbo with the digital dash. Same problem. The digital dash fuel level sending unit operates differently than the analog dashes. The fuel sending unit for the digital dash acts like a variable voltage divider sending a voltage to the dash instead of a variable resistance to ground. The moving arm is insulated from ground at the pivot point. The sending unit has not been available for years. I was able to repair his using parts from an available factory Toyota sending unit. It is a tricky repair but possible. It works flawlessly now. (This repair only applies to digital Toyota dashes) I purchased a Toyota sending unit part number 83320-39695 and used the wire winding part in the original digital dash fuel sending unit.
https://cimg0.ibsrv.net/gimg/www.yot...bd3732059a.jpg
Original bad digital sending unit
https://cimg1.ibsrv.net/gimg/www.yot...59fb2e73a1.jpg
New Toyota sending unit for analog dash
https://cimg3.ibsrv.net/gimg/www.yot...70c6c5e8b0.jpg
Moved the arm out of the way by bending a stop tab on the back side.
https://cimg4.ibsrv.net/gimg/www.yot...e5335a9bca.jpg
Unsolder the tab at the base of the analag unit
https://cimg6.ibsrv.net/gimg/www.yot...312170b570.jpg
Bad digital unit wires
https://cimg7.ibsrv.net/gimg/www.yot...7548518abe.jpg
Resolder after placing on the digital sender
https://cimg8.ibsrv.net/gimg/www.yot...8ccd2527a8.jpg
You will have to drill a hole at the top. see next picture with screw in place
https://cimg9.ibsrv.net/gimg/www.yot...7463a14a4a.jpg
screw installed at top to make the ground side circuit

Thank you for posting this... I'm about ready to fix mine...

Still haven't ripped into it... buy its on the list...