i have a 1986 tpi v8 trans am for those who may need to know.

ok i installed a digital dash and whenever i turn on any accessories like power windows or headlights or even turn signals the temp/h20 display goes way up
even when i hit my brakes to stop or slow down

even when i shift out of park and into drive the gauge is slightly affected due to the shifting gear switch

like just normally turning on the car, guages reads around 80ish because its summer time here. gauge will climb in value until it hits 215-220 as the car is on for a period time

normally driving around no headlights gauge will read about 215-220 degrees

i hit the brakes it will go up to 240ish

and brakes + headlights on = 260-280 degrees on the dash

i put down the headlights and let off the brakes and the gauge goes back to 220ish

same deal with putting my windows up or down. as soon as i stop usign the buttons the gauge goes back to normal

a friend said i needed a 12v relay for the gauge? is this so?



then another problem is i noticed my headlights dim when i use the power window switches


its really annoying with all these problems any solutions would be great.

and this may be the whole problem but im not sure please read and tell me what you think.

the preivous owner told me to keep this wire spliced or the car wont run. he said it was a wire that was spliced into an old after market security system but was since removed.

in front of the battery the owner has this semi-thick orange wire thats coming out of a harness that appears to be going to the firewall.

this orange wire is being spliced directly to the positive harness from the battery.


could this be causing my electrical issues? and how could i go about fixing it?


i dont see how my alternator could be the issue. i am able to start my car everyday and drive it everyday.

 

come on guys, ground problem, voltage regulator, alternator tapped into a 5v wire of a 12v wire


help me narrow down the possibilities

 

How much is "way up"?

 

and brakes + headlights on = 260-280 degrees on the dash

normal-215-230 depending how hot it is outside, day or night or how fast im going to get some nice cool air to cool the engine.

once i turn on my headlights it could jump 30degrees on the dash

brakes add another 20 degrees

and the nubers jump up n down 2-3 degrees when i use my turn signal

 

What does this mean, exactly?

 

alternator, tapped into a 5v wire of a 12v wire sorry missed a coma after alternator was just trrying to list possibilities


anyways from my knowledge there aree 5 volt and 12 volt wires that can be tapped into/spliced into/connected to - to power car accesories or additional components a car didnt originally come with

 

No, there are no 5 volt sources that you should be tapping into. How is it actually wired?

 

i believe my digital gauge is spliced into the stock 12v and ground that originally supplied the original cluster

i did this to avoid problems but i guess not