flashing "sys", blowing fuse - ZR-1 Net Registry Forums

rgfllamas · 04-26-2009

About a week ago I jumped in the car, a 91, and tried to start it, no go. Battery was low, it had been sitting 2 or 3 weeks. I pulled out the trickle charger and let it charge overnight at about 2 amps. Went for a ride yesterday, and noticed the "sys" light flashing and I was unable to get any readings from the DIC. Sys alternated with the instant MPG display which always displayed "0". I couldn't switch to any of the other options. Also noticed that none of the lights were on on the A/C panel nor was anything displayed on its read out.

Got home from the ride and grabbed the FSM to try to figure out what's going on. Tried to pull the codes but was unable, checked the A/C fuse since the manual says if it's blown you won't be able to pull the codes. It's gone. Installed new fuse and tried again. It blows. Checked the archives and saw a posting about side terminal batteries that also have top terminals shorting to the frame. I checked and sure enough it appeared to be shorted. I insulated the top post, replaced the fuse and tried again. It blows.

The electrical supplement shows that 10 amp A/C fuse supplying about 9 or 10 different circuits. As far as I can see the only way to find the short is trial and error, and if that's the case I need a whole lot more fuses.
I'm puzzled because everything worked prior to the low battery. I didn't boost or jump start the car, just used a 2 amp trickle charger, so I hopefully didn't overload anything, yet now I have a short.

Any suggestions before I go looking for a needle in a haystack?

04-26-2009	#1
rgfllamas Join Date: Aug 2008 Location: Palm City, Fl Posts: 32	flashing "sys", blowing fuse About a week ago I jumped in the car, a 91, and tried to start it, no go. Battery was low, it had been sitting 2 or 3 weeks. I pulled out the trickle charger and let it charge overnight at about 2 amps. Went for a ride yesterday, and noticed the "sys" light flashing and I was unable to get any readings from the DIC. Sys alternated with the instant MPG display which always displayed "0". I couldn't switch to any of the other options. Also noticed that none of the lights were on on the A/C panel nor was anything displayed on its read out. Got home from the ride and grabbed the FSM to try to figure out what's going on. Tried to pull the codes but was unable, checked the A/C fuse since the manual says if it's blown you won't be able to pull the codes. It's gone. Installed new fuse and tried again. It blows. Checked the archives and saw a posting about side terminal batteries that also have top terminals shorting to the frame. I checked and sure enough it appeared to be shorted. I insulated the top post, replaced the fuse and tried again. It blows. The electrical supplement shows that 10 amp A/C fuse supplying about 9 or 10 different circuits. As far as I can see the only way to find the short is trial and error, and if that's the case I need a whole lot more fuses. I'm puzzled because everything worked prior to the low battery. I didn't boost or jump start the car, just used a 2 amp trickle charger, so I hopefully didn't overload anything, yet now I have a short. Any suggestions before I go looking for a needle in a haystack? __________________ Ken 63 vert 91 ZR-1 #786 91 Z-07 (sold) 67 coupe (sold) 72 LS5 coupe (sold)