77 Chevy c20 picup electrical problems help please

[MerlinTT]

Hello
I have a 77 chevy c20 pickup that has some electrical problems
when you turn the key to the on position the dash lights come on, the turn signal green lights come on, if you pull the light switch out the dash lights go out the turn signal lights go dim, if you turn on right or left turn signals they blink and the other side blinks dimly.






oh the turn signal lights stay on lights on or off


I have replaced the light switch, replaced the printed circuit board on the dash panel, replace and added anther ground wire from the engine block to the firewall, I have looked for any broken or burnt wires and have not found any. Is there a ground wire to the fuse block?? if so what color is that wire?
there is no black wire


also the heater blower motor stays on when you turn the key on to
I put in a new switch for this to.
I know there has to be something I am overlooking
anyone else run across this??
Bill

 

[J Knight]

Where did you get the new printed circuit?

You either have a poor/bad ground connection at the back of the gauge cluster or somehow installed an incorrect printed circuit. That's my guess.

 

[MerlinTT]

well I got the printed circuit board at
http://www.classicindustries.com/shop/search/?q=25015092

but all these problems were all there before I started throwing parts at this truck
I think my next attack is going to find the ground wires and splice into them then ground the other ends in a new clean spot

 

[MerlinTT]

Did some digging on the ground wire
trace the ground from the dash panel to a
splice in the wiring harness were 6 ground wires are spliced into one wire that goes to a ground inside the cab. at that splice a crimp collar
the ground lead was corroded
the fix was cleaning all the ground wires and I added an extra ground wire lead for two different ground point!
Now it all work again!
and now I just got to figure out why the heater fan stays on all the time this is not a ground problem!

 

[GMCNUT]

If I remember right some older trucks had the heater fan run all the time the ignition was on. Somebody correct me if I am wrong.

 

[bucket]

Yeah, if it's an AC truck, the fan should run at a low speed at all times. Not sure what year that stopped.