Malfunctioning Water Temp Gauge

I posted this in the other forum but it zipped off the front page so fast I couldn't get an answer.

Hey guys 'n gals.

I took my instrument cluster out recently in order to fit metal rims to the surrounds, which look really nice now they're fitted. But it meant I had to remove the needles from the water temp gauge and the fuel gauge to trim them so they wouldn't jam against the new metal rims. The fuel gauge works fine now but the water temp gauge shoots right up to the top as soon as the key is moved to position 2 (before starting the car) and remains there until the car is turned off, wherein it slowly comes back down to the bottom.

What's going on? I made sure to replace the needles in exactly the same positions as I took them out so they wouldn't get messed up. Why would the water temp needle be shooting up like that?

I'll replace it if I need to, but I really hope it's just a case of resetting it or something. Help? :frown:

MikeKnight;12453 wrote: I posted this in the other forum but it zipped off the front page so fast I couldn't get an answer.

Hey guys 'n gals.

I took my instrument cluster out recently in order to fit metal rims to the surrounds, which look really nice now they're fitted. But it meant I had to remove the needles from the water temp gauge and the fuel gauge to trim them so they wouldn't jam against the new metal rims. The fuel gauge works fine now but the water temp gauge shoots right up to the top as soon as the key is moved to position 2 (before starting the car) and remains there until the car is turned off, wherein it slowly comes back down to the bottom.

What's going on? I made sure to replace the needles in exactly the same positions as I took them out so they wouldn't get messed up. Why would the water temp needle be shooting up like that?

I'll replace it if I need to, but I really hope it's just a case of resetting it or something. Help? :frown:

Sounds like you may have damaged the gauge. :frown:

Can just the gauge be replaced, or can I take it out to fix it myself? I'm an electronic technician by trade so I'm not exactly an ape with a soldering iron. I tried to remove it very gently earlier today but it seems glued in.. or affixed to the back somehow.

I really want to avoid having to change the entire cluster.

EDIT: Just to be clear, everything else in the cluster works flawlessly. It's just that one gauge.

MikeKnight;12453 wrote: I posted this in the other forum but it zipped off the front page so fast I couldn't get an answer.

Yes you did, it just didn't solve your problem!

Yep the gauge can be replaces separately once you take the pod apart.

Oh thank god. Time to look for a new gauge then.

Sorry talkingcars I didn't see your reply until I checked the thread recently, it whizzed off the page so fast.

From experience, I would never remove needles from dials etc. They tend never to work properly again.

The unit itself usually works using a bimetalic strip coiled to form a spring. The more current that flows the more one half of the bimetalic strip expands. This causes the spring to "unwind" and moves the needle.
It is possible that the spring has unwound slightly when the needle was removed. This means less spring action and even a small current will give full scale deflection. You can try removing the needle gain and turn the centre anti clockwise before putting the needle back on. It might work, or it might break it completely, but what have you got to lose?

If you try this and the action improves but you still get a high reading then do the same again until it looks about right.

Remember, it is just an indication and is pretty inaccurate anyway.

Ah, that'll be the problem then. When I removed the needle the spindle came out with it, so I've no doubt now that the spring has unwound completely. I'll have to gently mod the new needle while it's still attached. I have small snippers and a precision tip on my dremel so it shouldn't pose too much of a problem.

Thanks CJJ!

Fixed it!

... and broke my foglights. :err:

I'm pretty sure I'm the Frank Spencer of auto electrics.

MikeKnight;12547 wrote: Fixed it!

... and broke my foglights. :err:

I'm pretty sure I'm the Frank Spencer of auto electrics.

Ooooh Betty! I've had a bit of trouble, mmm.