HEEEELP...GOT A '86JIMMY 2.8 RECENTLY THAT WAS A NO RUN, FIXED SHORT IN ECBM CIRCUIT, NOW RUNS FINE BUT SES LIGHT WILL NOT COME ON AT ALL, HAVE CHECKED FOR SIGNAL AT CONNECTOR TO I. CLUSTER AND NOTHING, BULB AND SOCKET ARE NEW AND WORK.....ANY IDEAS?
Most likely its a short-induced failure on the circuit board of the computer. A blown bulb, voltage spike or short can cause this. Count your darn blessings!!!! Leave it alone and don't look back. On an 86 the SES light won't tell you anything wortwhile anyway. SES lights come on only when something affects emissions, they are a motor company scam, and are only there to annoy customers and make money for GM. Count your blessings that yours doesn't work, othewise it will come on every week telling you that your aging carb just dumped an extra drop of fuel and the O2 sensors didn't like it. The light will stay on for three days and then come on again because your air pump isn't making quite enough air.
I was counting my blessings on my 87 Olds Cutlass that my SES light never came on. I put a new air filter in and I couldn't get it to go away. It was code 21 which was "idle too low" even though the idle didn't change. On 80s GM cars, I just clip the wire and ignore it.
No "service Engine Soon" Light
