Clusters, Gauges, Speedo & Odo meters

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Rudi
My gratitude to you for all the research work done on Clusters and Gauges.
The Fuel gauge of my BJ 40 (1982 24V) stopped working & I found that the Dropper Resistor does not gives out 12V to the fuel gauge. 24V comes out of it.

I made an Electronic unit using LM 317 Regulator & which gives out around 7.08 V. There are 3 terminals on the rear of the Fuel Gauge & to which shall I give this 7V ?
I presume that it is the middle one, by- passing the mechanical regulator. Kindly advice. Thank you
 
WDT Siri said:
Rudi
My gratitude to you for all the research work done on Clusters and Gauges.
The Fuel gauge of my BJ 40 (1982 24V) stopped working & I found that the Dropper Resistor does not gives out 12V to the fuel gauge. 24V comes out of it.

I made an Electronic unit using LM 317 Regulator & which gives out around 7.08 V. There are 3 terminals on the rear of the Fuel Gauge & to which shall I give this 7V ?
I presume that it is the middle one, by- passing the mechanical regulator. Kindly advice. Thank you
Click to expand...
Yes the middle one - it also feeds straight across to the temp gauge
 
First off, Thank You Rudy for the this awesome thread!
I'm trying to get my Temp and Oil gauges to work in my 74 (3rd gen cluster). All gauges pass the 3.4W light test and all sending units put out enough ohms.
Is this scratch at terminal A(+) causing a short???
If so what can I cover it to stop the short?

Thank You to All You Cruiser Heads in advance!!!

20250216_120702.webp
 
PuKE said:
First off, Thank You Rudy for the this awesome thread!
I'm trying to get my Temp and Oil gauges to work in my 74 (3rd gen cluster). All gauges pass the 3.4W light test and all sending units put out enough ohms.
Is this scratch at terminal A(+) causing a short???
If so what can I cover it to stop the short?

Thank You to All You Cruiser Heads in advance!!!

View attachment 3840153
Click to expand...
If your gauges and senders appear to be working correctly, then my next guess would be a bad connection in the harness somewhere in between.
Check the gauge has power to it, and then try running a wire from the temp sender directly to the gauge.
 
45Dougal said:
If your gauges and senders appear to be working correctly, then my next guess would be a bad connection in the harness somewhere in between.
Check the gauge has power to it, and then try running a wire from the temp sender directly to the gauge.
Click to expand...
That's what I figured too. Already on it 😁
 
Nolacajun75 said:
Thank you so much! I just ordered a new circuit board. Hopefully that will solve my problem. My temperature gauge started working for some reason. I have no idea why and it has all week. Just my fuel gauge is not working now. Maybe this will solve that problem
Click to expand...
Hi Nolacajun75, I have a similar problem on my clusters circuit board, one of my bulbs trace has been broken, no illumination on the left side of cluster. Where were you able to order a replacement circuit board? I haven’t been able to locate one for my 78’. Thanks
 
BuckMark said:
Hi Nolacajun75, I have a similar problem on my clusters circuit board, one of my bulbs trace has been broken, no illumination on the left side of cluster. Where were you able to order a replacement circuit board? I haven’t been able to locate one for my 78’. Thanks
Click to expand...
BuckMark,
Fyi - If the problem you're having is just due to a broken trace on the speedo circuit board, you may be able to solder a jumper wire across the gap/break or maybe just a little solder blob. Clean and sand the tarnish off in the spot first so the solder sticks to both sides of the break. A little flux helps too.
 
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Yea these boards are really simple - a soldering iron is cheaper than a new board and keeps it original :)
Scrape off the blue varnish; you can replace it later with nail varnish or similar.
A short length of copper wire to bridge the gap might help - watch out where you route it if its near the connector.
 
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Depending on the situation you can solder it or bridge it. Here’s a picture of mine where I’ve done both.

IMG_2602.webp


IMG_2601.webp
 
1964 FJ40 gas gauge will not coincide with the amount of fuel. I grounded the sending unit...the gas gauge will go all the way up (as mentioned to test it). Put in a different sending unit and it acts the same, not working. With a full tank the gauge only shows 1/4 full. Could it be the gauge is messed up? I did take it out last year and didn't look bent or anything....but now just wondering if a replacement gauge might work. Anyone have a spare that I could try?
 
sleepycruiser said:
1964 FJ40 gas gauge will not coincide with the amount of fuel. I grounded the sending unit...the gas gauge will go all the way up (as mentioned to test it). Put in a different sending unit and it acts the same, not working. With a full tank the gauge only shows 1/4 full. Could it be the gauge is messed up? I did take it out last year and didn't look bent or anything....but now just wondering if a replacement gauge might work. Anyone have a spare that I could try?
Click to expand...
Worth checking that it's getting a good supply voltage - do it both with and without the grounded signal lead to see if it changes.
Could be a poorly seated fuse or a loose / corroded upstream connection.
 
45Dougal said:
Worth checking that it's getting a good supply voltage - do it both with and without the grounded signal lead to see if it changes.
Could be a poorly seated fuse or a loose / corroded upstream connection.
Click to expand...

It has been a while since I did any troubleshooting, but I am pretty sure I ran separate wires direct and it did the same thing. I might have to take it apart again and test that just to confirm.
 
I got a different gas gauge from @JVZii a few months back. I have not had a chance to install it yet, but I did run two wires off the top of the float mechanism (where the two wires connect) to the ‘new gauge’ and when I turned the vehicle on both gauges went close to full (but not all the way full like when it is grounded). The original gas gauge just goes back to show Empty otherwise. Weird.
 
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