1968 Pontiac Firebird 400 Standard transmission 4 speed 58000 miles
my problem is that when i turn the ignition key to crank the engine it does on the run position. I thought it could be the ignition switch so i replace it. but it still did the same, So i said it could the key cylinder,so i replace that, but that didn't work either. check my wire connections.but i can not see what could be the problem. This car was sitting in my garage for many years. I had a chevy camaro engine in it before i decided to replace the engine with its original firebird engine. my problem began when i did that. I had no issue with the ignition until i made the changes. does anyone have the same problem i have how wasit fix.i been at this for a few month now and no one knows what could it be.If Scotty kilner does not know this problem then I'am DOOM. {black}:razz:
On that original '68 engine the Starter had a "S" and an "R" terminal.
The way it worked was when you turned the Key to "Start" Power went from the ignition switch (on the Purple wire) to the "S" terminal to energize the Starter solenoid.
Internally in the solenoid, Power was provided to the "R" terminal and that Power went up to the + terminal of the ignition coil to provide maximum battery voltage to the ignition coil (because of battery voltage dropping while the starter was turning).
When you released the ignition switch from the Start position to the Run position, Power was removed from the "S" terminal and (internally) Power was removed from the "R" terminal.
In the Key Run position, Power was provided to the + terminal of the coil through a resistor wire which reduced power to the + terminal of the coil to around 9 volts.
Long story short, try removing the wire from the "R" terminal on the starter solenoid to see if there's an internal short in the Starter solenoid that's backfeeding power from the ignition coil + terminal to the "S" terminal on the starter. One way or another you have Power getting shorted to the Purple wire, either internally in the Starter solenoid or externally in the wiring.
Needless to say, if you updated the starter to a starter with only an "S" terminal and NO "R" terminal you can't have that wire that goes to the ignition coil + terminal on the "S" terminal with the Purple wire.
Check grounds and get yourself a wiring diagram, look for a short circuit in that 56-year-old wiring.
Sorry to say. I need a person that had the problem and was able to fix it.Looking at a diagram will not tell me what to look for
The chances of anyone else here having had the same problem on a GM car of that vintage that can tell you what specific wires to check are somewhere between slim and none. A wiring diagram will tell you what wiring is involved in the starter circuit which will let you know where you need to look.
The worst case scenario would be just putting in your own wiring to replace the faulty circuit. I used to do that kind of thing all the time on really old cars. They have very simple electrical systems but if a fault is deep inside the wiring harness it can be easier to just wire around it.
O.k Thank You, I'll Keep searching In other Places.
.Looking at a diagram will not tell me what to look for where do i start.
Looking at a diagram will tell you where the short is. I found a link to RockAuto that is of the GM original service manual. More Information More Information for DETROIT IRON DCDGM139 (rockauto.com) I have a '79 Pontiac whose horn wouldn't honk -fixed with a wiring diagram, also from GM. That thing has had 56 years' worth of potential corrosion (copper oxidation) to take hold. We can't see electrons; we have to interpret where they're going to, which requires a wiring diagram.
It appears that he doesn't want to do basic electrical troubleshooting but instead wants to know what specific wires may be shorted. I probably have a wiring diagram for that car in one of my old Chilton manuals but it would take some digging to find.
Maybe. I linked a wiring diagram in CD form. There's also a paper manual made by GM itself.
I need answer to the problem, were could the short be. Have anybody had this problem, they have a short where did they look or start. saying i have short it's no help. Sorry to say. I need a person that had the problem and was able to fix it.Looking at a diagram will not tell me what to look for where do i start. {black}:idontknow:
need precise help, saying i have a short, and get a diagram. is to me like looking for a needle in Haystack. thank you.