89foxbodyHO

Hey guys new member here and i need some help. Its an 89 foxbody 5.0 ho and i have a problem with my high beams i cant figure out. When i turn my headlights to high beams my temp gauge goes all the way up past the red mark, battery gauge drops all the way down, both of the turn signal lights on the dash come on and stay on, the tach stops working and all the lights behind the dash on the right side turn off(from the speedometer over). Also with the high beams on the left side dash lights blink with the blinkers if i turn them on. none of the headlight wireing has been cut or spliced ive never seen anything like this. if anybody has some tips or idea they would be much appreciated.

eb2gt

sounds like it might be in the multi switch (turn signal switch etc.)

89foxbodyHO

Also i just came to realize without the key in the ignition if i turn the headlights on and turn them to high beam the fuel pump primes and the door buzzer dings just like if i turn the key to the on position. weird? is it possible the multi funtion switch is gone to crap causeing this?

89foxbodyHO

the car also came with no fog lights the plugs are just danggling could that cause the circuit to not be fully closed or something?

90_notch

As long as the terminals in the fog light plugs are not shorting out due to corrosion or something this should not cause any issues. You probably have either a bad multifunction switch, or you may have a bad ground behind the dash, or going to the gauge cluster. I would check the wiring first before ordering any new parts you may not need. I had a bad ground to the headlights before, and it caused all sorts of issues until I found it. It sounds more like a problem at the cluster to me. As you add another hot wire to the cluster to light the highbeam light the whole cluster freaks out. Look for a bad ground at the cluster. An easy test, is to tie into the ground wire at the plug on the back of the cluster, and run to a good chassis ground and see if this helps. You may want to use a fuse link in your test wire as well, just in case you tie into the wrong wire by mistake. This will keep you from burning up the car. If you have the right testers, you can usually figure out the hots and grounds pretty easily. Some wiring diagrams are online as well.

89foxbodyHO

Thank you sir im in the process of checking all grounds ive had many people pointing fingers towards a ground.

90_notch

Hope all goes well as a bad ground can be a real pain.