Ground is good, got 12 volts but missing 7 volt, research says the 7 volt comes from the 12V through a voltage regulator/limiter. Can’t find the limiter, supposed to be on the back of the printed circuit board of instrument panel. Problem started when I replaced the panel bulbs with LED’s, I had also replaced the glow plug relay, controller and shutoff timer relay at the same time. Any help would be much appreciated!!
L35 temp and fuel gauges not working
- Thread starter Treb
- Start date
Sawdust&Shavings
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Equipment
BX1870,LA203A,BX6315,BX2767,RCK48-18BX,GCK60-23BX
Any chance the fact that LEDs draw significantly less current than 12 volt incandescent bulbs is part of your challenge?
I kicked that idea around but according to the wiring diagram it shouldn’t make a difference, plus all the lights are off once the tractor starts up. It’s no big deal to put the bulbs back in to see if that makes a difference.
would need to see picture of the panel as well as wiring diagram though it sounds 'old skool' + 12 to VR to gauges to sensors. so no LEDs will not be the problem.
You could have lost ground to the VR, depending on type of VR used. Old style would be bimetallic controller, new will be electronic.
You could have lost ground to the VR, depending on type of VR used. Old style would be bimetallic controller, new will be electronic.
The gauge with the 4 terminals is the fuel gauge, the one on the other side is the temperature. Serial # for the tractor is 64690, best I could find out DOM is between 2001 and 2003, the L35 was produced from 1999 to 2004. Still have not found the voltage regulator/limiter that produces the 7V from the 12V, it’s not on either side of the instrument panel board.
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It's internal within the 'fuel gauge'. The 'gauge' (meter) only needs 2 connections, source of power and sender.
Your 'gauge' has 4 connections +12 input, ground, sensor( marked F.U) and 7V output...to temp gauge).
If you measure between ground and '7V' you should get 7 volts.
sure is a nice CLEAN flexiPCB !!
Your 'gauge' has 4 connections +12 input, ground, sensor( marked F.U) and 7V output...to temp gauge).
If you measure between ground and '7V' you should get 7 volts.
sure is a nice CLEAN flexiPCB !!
That’s the thing between + and ground I have 12V but nothing between 7V and ground. The trace from 7V on the fuel gauge runs over to the 7V on the Temperature gauge, so if the 7V is created by the fuel gauge and it goes bad then you lose your Temp gauge also, that’s not a good setup!!
well the only way to prevent that would be to have a separate +7V regulator for the temp gauge.
maybe take the fuel gauge off the PCB and see what's underneath it on the front side ?
if you need to , you could buy a voltage regulator chip to replace the one inside the fuel gauge.
maybe take the fuel gauge off the PCB and see what's underneath it on the front side ?
if you need to , you could buy a voltage regulator chip to replace the one inside the fuel gauge.
I will pull that one off tomorrow and take a look at it, wish I had a verible power supply I would set it to 7V and hook to the temperature gauge to see if it works.
easy to test...
you can use a 6 volt battery or even a 9 volt to test the temp gauge--sensor--gnd.
also use 12volts if you 'pulse' it ( on/off) say at 1 pulse per second
mechanical gauges are 'tough' so usually no damage
if you briefly ground the 'sensor' connection ,gauge will read 'full or 'max'.
you can use a 6 volt battery or even a 9 volt to test the temp gauge--sensor--gnd.
also use 12volts if you 'pulse' it ( on/off) say at 1 pulse per second
mechanical gauges are 'tough' so usually no damage
if you briefly ground the 'sensor' connection ,gauge will read 'full or 'max'.
Thanks, I had considered using a 9V battery but didn’t know how sensitive the bimetallic was, this is my first rodeo with these type of gauges.
old skool...real gauges, they are slow to respond.
the reason for the voltage regulator is to give a better 'response', more accurate reading.
if it is kaput, you can replace with a LM317 voltage regulator, 240r resistor and a 1100r resistor.
the reason for the voltage regulator is to give a better 'response', more accurate reading.
if it is kaput, you can replace with a LM317 voltage regulator, 240r resistor and a 1100r resistor.
Yeah the the wire going from the VR to the 7V terminal is burned into and the VR looks to be shorted. Wish someone sold them but probably have build one.
I googled '7 volt regulators' and this...
..popped up !
For $20 it might be a good gamble... EASY to install. I don't know what it powers but should handle the 2 gauges.
There may be others out there.....
Jay
7 Volt Regulator for CX/GL
Brand new heavy duty sealed 7 volt regulator with the proper terminals for your app. Also available in universal fit where you install the right terminals or solder and heat shrink. It has a mounting…
murrayscarbs.com
..popped up !
For $20 it might be a good gamble... EASY to install. I don't know what it powers but should handle the 2 gauges.
There may be others out there.....
Jay
I saw that earlier today, I also saw one on Amazon but it was only rated for 1 amp, you think that would be enough for 2 gauges? I like to buy off Amazon if possible, their return policy is so super easy. Plus I would have it in 2 days instead of the 7 to 10 days with the other one, only reservation was the 1 amp limit.I googled '7 volt regulators' and this...
7 Volt Regulator for CX/GL
Brand new heavy duty sealed 7 volt regulator with the proper terminals for your app. Also available in universal fit where you install the right terminals or solder and heat shrink. It has a mounting…murrayscarbs.com
..popped up !
For $20 it might be a good gamble... EASY to install. I don't know what it powers but should handle the 2 gauges.
There may be others out there.....
Jay