Temp Gauge Fix.

I have been having an issue with my truck running too cold for a while now, the temp gauge would only get to a little below the 1/4 mark. So of course the first thing I thought was that my thermostat was stuck open so I replaced it. Well this made no difference to the gauge, so I thought maybe the sender had gone bad so I replaced it but Still no change on the gauge. So I thought maybe the gauge itself was broken so I went and got an aftermarket electronic temp gauge and it showed really cold also (120F). So as a last resort I ran a ground wire from the sender to the chassis to make sure it had a good ground and now it reads perfect, right on the dot 180F. So if you are having issues with your truck running too hot or too cold check your engine to chassis grounds before throwing a bunch of money at the cooling system because it might just be bad grounds causing the gauge to read wrong. I hope this is able to help some of you out, have a good one!

Good job. Did you first try loosening, then retightening the sender?

Running without a thermostat will NOT keep your vehicle cool or cooler UNLESS that thermostat was stuck closed or partially stuck closed.

I'll have to check this out... My gauge has never even reached half way.



Fred

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This is interesting, I had the same problem that I never found exactly why it was working properly again, this explains A LOT!

My temp gauge was never getting over the cold bar, it would go up a little and stay there. I had determined my truck was running at the correct temp (or at least close to it) with an IR thermometer and just figured the sender was bad and ignored it.

Then I blew my motor, pulled it, rebuilt it and CLEANED ALL THE GROUNDS when I put the rebuild in and it suddenly worked correctly! I thought it was just from the fresh rebuild and cleaning of the coolant passages or something. This makes complete sense now. I have since even added a few extra ground wires throughout my B to solve a few lighting and dimming issues too. Kind of went overboard with the grounds but it doesn't hurt to have more. (Engine to body, Engine to chassis, Chassis to body, Chassis to bed, all with 4 gauge wire) I go through a lot of mud so I wanted to make sure that grounds wouldn't be an issue if muddy water and such got EVERYWHERE.

Thanks for the information.

Also, failure to bleed out all the air out of the cooling system can result in strange readings, and also cause to run hot.

Its amazing how overlooked good grounds always are, you sure can never have too many!