voltage over/under then temp gauge spike

[nightmare 98]

my 98 gst is running hot, I expected it to an extent as I have not finished the exhaust so I have some leaks, I did a full build on a 1st gen and added my t-3 turbo and wastegate. the baffling issue is that the guage shows normal temps and then it gives the brake and battery light, the gauges get very bright and the temp gauge pegs out! Is this an electrical issue of is the temp actually changing that dramatically?

 

[Turbo T]

temp can go up quick but seems to be faster then normal how you described.. is the car acting like its over heating? can you smell hot coolant?

 

[nightmare 98]

it's hot but not over heated, in the 210-220 range, my fans engage at 210 and disengage around 200 according to the scanner. but I haven't had the opportunity to drive it with the scanner to create recreate the situation and check the temps.