I have found the Spyder dash I have (a pretty cool early 60's dash layout) has a bad resistor in the gauge (you can see the damage below), probably from carry it around for about 20 years (!). These gauges are connected to the 0-30 ohm style sender that was common for GM for many years (I did test the sender). Pretty easy to get to and replace, but what to replace with?
Some online info is saying the resistor should be 90 ohms (maybe 87?), but this might be for the 90 ohm (65+ senders). In testing the gauge from a non-Spyder dash, it seems to be showing around 22 ohms (should it be 30 ohms?). Does that seem correct? (It does work from what I can tell, I did test it). I am not sure how that would be calculated. Another forum (for 50's Chevys) is saying 39 ohms.
One source says that the purpose of this resistor is to simply slow down the movement of the needle. So maybe the value is not wildly important(?)
What say GRM? Find another 22 ohm (ish) resistor and slap it on? Any particular type that I should look for (clearly the original was a ceramic type). I certainly don't mind a modern style. I am a bit unclear as to how much wattage is involved. I has to be small, right? Do I need a 5 w (shown below) or one of those tiny 1/2 watt versions (also shown below).
Now, I know someone will say: "Hey just hack the one off the gauge you have that is working and solder it on!" Yeah I could do that, but that would not give me a backup dash if I F' it up. After 60 years, I also suspect it's a wee bit fragile!
