140 fuel gauge sucks

[1968 volvo]

It sucks also the whole cluster sucks except the speedometer which is the top g except it?s not accurate at all. I have a really strange problem with the fuel gauge. When driving one time I noticed it was going up and down a lot not like just the fact that the gauge sucks but like empty and then back up to whatever my fuel was actually at. Fuel sender is new, the wire going from sender is good, and the voltage regulator is the upgraded one I bought off of here. Here?s what?s weird. If I bend the circuit board towards the gauges, the gauge works but if it bends back to neutral, it is intermittent and if it?s bent the opposite way it fails completely. Has anyone ever had this problem? I had two fixes I considered trying. The first one would be to put some small washers in between the circuit board and the instrument housing so it bends into a working position. I don?t know how long this will last and it seems janky. The second solution I can think of is to wire directly from the source (after the voltage drop) to the gauge. This seems like it would be more permanent but I don?t know what wires go where?

Also is there a temperature sender that actually reads right? I have one from rock auto that reads far too low like the needle moves just barely when it?s at operating temperature and one from vp that reads far too high like completely overheated when it?s at operating temperature. There is a much more expensiver one on vp I think but it that one close?

 

[1968 volvo]

Or the gauges are leaving for a custom cluster put in it?s place

 

[lookforjoe]

Do you have the spring washers behind the nuts that hold the gauges to the circuit board? If there are cracks in the circuit board, you can solder wire bridges to compensate.

 

[1968 volvo]

Spring washers?

 

[1968 volvo]

Say more

 

[hiperfauto]

The parts catalog doesn't show a washer under the gauge nuts and there aren't any on the cluster I just looked at. Is that something Volvo recommended?

It's common for the gauge nuts to come loose and cause erratic readings. Snug them down and see if the problem persists. Also check that the pins on the board aren't loose and that the terminals fit tight on the pins.

 

[planetman]

It's sometimes necessary to clean the contact area on the PC board for the gauges. You'll have to remove the PC board from the cluster assembly and then remove the gauge(s) to access and clean the contact areas.

And as hiperfauto recommended, you may need to tighten the connectors inside the plastic wire holders. The connectors are tube shaped and have a seam. The seam can open up over time making for poor contact. With a small tool/pick you can carefully make the tube smaller by prying.

 

[lookforjoe]

The parts catalog doesn't show a washer under the gauge nuts and there aren't any on the cluster I just looked at. Is that something Volvo recommended?

It's common for the gauge nuts to come loose and cause erratic readings. Snug them down and see if the problem persists. Also check that the pins on the board aren't loose and that the terminals fit tight on the pins.

My recollection of my 140's was that the gauge studs used a 'wave' washer to maintain good tension on the nut seating at the circuit board - as with my Fiat

I would suggest adding them

 

[1968 volvo]

I got the gauge working well. I tightened the nut a bit more than I thought to be healthy but it seemed to get it done so. I was really scared to do that because the last gauge I had the post snapped off when I tried to tighten the nut much, that must?ve been a freak accident cause this one was fine. I really didn?t even torque the last one down much at all btw it gave up its spirit quite easy which is why I was going easy on this one.

Anyone know of an accurate temp sender?

 

[1968 volvo]

It?s alive.