but I think I blew it myself, just haven't had the chance to prove it. The needle is stuck all the way hot, whether the ignition is on or off.

Here is what I did. I have a Hayden thermal switch installed in the radiator, to turn on the sec fan. I recently wired one of the "extra" idiot lights in the instrument cluster, to come on when this switch closes. I put a bulb and socket in the left side of the cluster, it is a red lens with a symbol like low oil or coolant. When the Hayden switch closes, it completes a circuit to ground, turns on the fan, and the lites the bulb. That way i know when it comes on. All the bulbs in the cluster are pulled up to 12v, either all the time or when ignition is on. So you just ground the other side of the bulb to light it up.

I tested my new idiot lite, and it all seemed to work fine. But I didn't drive the car for a few days, then when I did I noticed the stock temp gage was pegged. Not really sure when it happened, maybe on that first startup.

I haven't had time to pull the cluster out to check the gage. Do these gages just fail every so often? I checked the sending unit, and that seemed to be ok. I was wondering if somehow the coolant gage is wired up to this idiot light, which is not used the way GM built my car. Maybe I blew the gage with my addtion of the light.

Just thought I would post this to see what y'all think.

 

When I just did my engine swap I had the same problem. I took
off the plastic face plate and then removed the metal surround
in front of the quaqe cluster. I tapped the needle and it fell back
down and is fine now. What had happened is the metal surround
infront of the gauges has a lip around the edge of the holes and
the needle got caught on there. I hope this helps .

 

Wow, that's a great idea. Now that I think of it, you could be on to something. When I start the car, the needle always seems to peg during crank, then return to normal. So looks like my needle may just be "stuck".

Pulling the cluster is kind of a PIA, but just pulling that front face plate and bezel should be a snap. I will check it out tomorrow.

I really can't figure what I did with that idiot lite, that would cause the gage to peg.

I hope you are right! TIA

 

Well I got this issue resolved tonight. I pulled the bezel off my instrument cluster first, then the clear plastic lens. I could then access the gage needles. Sure enough, my temp gage was stuck. I freed it up, played with it a bit, then put it back togother. Then I started the car, and sure again it pegged and got stuck.

So I took it all apart again, this time taking the metal plate that goes in front of all the gages. I played with the starter key, watching what the needle was getting stuck on. It seemed to be just hitting the outer edge of the gage, and just had so much force when the starter was hit, that it kind of got hung up on the edge of the gage. It was like at 1:00 position.

What I did to prevent this was put a little piece of black electrical tap, kind of inside the edge of the gage, preventing the needle from getting stuck. With the ign key, there is a "pre-start" postion, which you can hold, that doesn't actually engage the starter motor. When I did this, the temp gage needle would slam to it's furthest postion, and bounce a little and remain at about 12:00 postion, as long as the key was held. When I released the key, back to ign run, the needle would go back to its home position.

I tested this out quite a bit, so looks like I got it licked. I kind of amazed that this needle pegs and bounces everytime you start the engine, but I guess this is normal. So glad I didn't have to buy a new gage!

Thanks much Nazz, for the tip.:hail:

 

Well I got this issue resolved tonight. I pulled the bezel off my instrument cluster first, then the clear plastic lens. I could then access the gage needles. Sure enough, my temp gage was stuck. I freed it up, played with it a bit, then put it back togother. Then I started the car, and sure again it pegged and got stuck.

So I took it all apart again, this time taking the metal plate that goes in front of all the gages. I played with the starter key, watching what the needle was getting stuck on. It seemed to be just hitting the outer edge of the gage, and just had so much force when the starter was hit, that it kind of got hung up on the edge of the gage. It was like at 1:00 position.

What I did to prevent this was put a little piece of black electrical tape, kind of inside the edge of the gage, preventing the needle from getting stuck. With the ign key, there is a "pre-start" postion, which you can hold, that doesn't actually engage the starter motor. When I did this, the temp gage needle would slam to it's furthest postion, and bounce a little and remain at about 12:00 postion, as long as the key was held. When I released the key, back to ign run, the needle would go back to its home position.

I tested this out quite a bit, so looks like I got it licked. I'm kind of amazed that this needle pegs and bounces everytime you start the engine, but I guess this is normal. So glad I didn't have to buy a new gage!

Thanks much Nazz, for the tip.:hail: