main cab power wire?

[manyholes]

is there a main power wire that feeds the dash and fuse box? my pyro goes nuts when i turn my headlights on but if i play with the heater and fan speed i can either get it to stop going nuts or it just pins itself straight down. checked fuseable links and all seemed to check out ok. headlights have been giving me some grief, mostly flickering on high beams but only on lower revs, charging system has been replaced, battery, alternator, voltage regulator. checks out at 14 volts when running. any ideas where to start? the pyro is tied into power windows fuse block because the '90 doesnt have p/w's so it was an open power source.

thanks guys

[Gots_a_sol]

poor grounds sound like your problem

[manyholes]

the grounds under the hood are good, where are the grounds in the cab?? i cleaned up the batter posts even though its a new batt, engine ground, body ground by battery, voltage reg tight into sheet metal. basically anything i could find under the hood, i cleaned and tightend.

[PToombs]

Ground strap from the back of the head to the firewall? The dash ground is right of the steering column on a metal bracket.

[collegekid]

what kinda pyro is it?

[manyholes]

its a swing gauge autometer phantom 2 i believe

[manyholes]

hey toombs il check the colum ground, thanks for the input guys