290sp square trim gauge issues

[rscottdds]

I have an older style square trim gauge that’s having issues. It will say -4 when it’s all the way down for a bit like it’s supposed to but then just start showing random numbers. I changed out the potentiometer to a new one but it didn’t change anything. I had an issue a few years ago where the gauge wouldn’t change at all (stuck at 65 or something) so I got a replacement and it worked up until recently. Is the gauge bad again? Is there a way to troubleshoot? Those gauges are hard to come by and expensive so I don’t want to get one without being fairly certain it will fix the problem. This is all with the key on but engine not running.

Thanks for any help.
Robert

 

[Scott Danforth]

Check your connections. And yes they are expensive and NLA

 

[QBhoy]

Hi. Did you calibrate the new potentiometer when you replaced it ? There is a fairly easy procedure to follow as per below

 

[rscottdds]

Thanks for the responses. Yeah I did adjust the unit like in the vid. It read -4 when all the way down but then has a mind of its own a few seconds later. Sometimes I can trim her up and it will stay consistent for a minute or so at -1 but then go off again. I’m going to trace the wires as much as I can to see if there is a loose connection/short/pinched wire (I just did a repower so they put in a new harness) but I think my money is on the gauge since they didn’t touch the trim wires.

Robert

 

[QBhoy]

Thanks for the responses. Yeah I did adjust the unit like in the vid. It read -4 when all the way down but then has a mind of its own a few seconds later. Sometimes I can trim her up and it will stay consistent for a minute or so at -1 but then go off again. I’m going to trace the wires as much as I can to see if there is a loose connection/short/pinched wire (I just did a repower so they put in a new harness) but I think my money is on the gauge since they didn’t touch the trim wires.

Robert

Sure you’ve checked, but thought I’d ask if the sender cog still has all its teeth present and none missing ?

 

[kenny nunez]

I Re powered several boats with the square trim gauge, I kept asking for the square hole saw tool that was needed but never got an answer back.
My local Volvo service rep told me that whoever designed that gauge must have also the been same person who designed pin ball machines!
Merry Christmas and a Happy New Year!

 

[Scott Danforth]

The square hole on the original dash was cut with either a sawzall or pneumatic body saw from the original stamped round hole

 

[kenny nunez]

Scott you are right but I always liked to aggravate the Volvo people about the square gauge. I never could get an answer as to why it was square.
Merry Christmas and a Happy new Year!

 

[QBhoy]

Scott you are right but I always liked to aggravate the Volvo people about the square gauge. I never could get an answer as to why it was square.
Merry Christmas and a Happy new Year!

I’ve got a possible answer why…

 

[kenny nunez]

Great picture.
My son says that the only measuring device Volvo designers have is a
framing square.

 

[Scott Danforth]

Great picture.
My son says that the only measuring device Volvo designers have is a
framing square.

But a Ford Windsor V8 fits just fine in those square body Volvos

 

[QBhoy]

But a Ford Windsor V8 fits just fine in those square body Volvos

I had an old xc90 for a while. Legend has it that in the 12 or something years that particular first type model was around…not one single direct fatality occurred whilst within one. If that’s true…there likely isn’t anything else that can get close to that statistic?

 

[Scott06]

I’ve got a possible answer why…

These and the 240s were the best cars they made, for years had a 1995 940 wagon, wasn’t fast but it made up for it by being slow…

 

[QBhoy]

These and the 240s were the best cars they made, for years had a 1995 940 wagon, wasn’t fast but it made up for it by being slow…

Haha. I get you. The 850 T5R wasn’t half a bad machine. The cops here used them all tricked out with remaps and goodies

 

[Scott06]

Haha. I get you. The 850 T5R wasn’t half a bad machine. The cops here used them all tricked out with remaps and goodies

T5 was a different animal than the non turbo (114hp) i had…

 

[QBhoy]

T5 was a different animal than the non turbo (114hp) i had…

Lovely engine in turbo or non turbo form. Straight 5 thing. Sounded lovely. Think it was shared with ford for a while.