99 silverado security light comes on

i have a 99 silverado z71 while driving the security light ,batt light,low fuel light come on and th gas gadge reads e, the abs light comes on, i have no gear indicator,no hi-beam indicator light, and the temp. gadge reads that it is still cold even when its blowing heat but the truck still runs fine justwanting to find out what is going on this all happens at the same time also

Check the ground strap between the firewall and engine. I had a weird electrical problem on my 00 and that was the problem, bellhousing bolt was loose. Tightened it up and has been fine ever since.

if i pound on the gas tank the light seems to go out but i comes back on after a while i am thinking it may be the fuel tank sending unit


and has anyone had problems with the trannies on these my fluind looks like pepto bismo i think the coolant is leaking into the tranny

My 01 z71 has the fuel sending unit going out but it doesnt effect anything other than the fuel gauge. Just jumps back and forth from e-f. Sounds like a wiring problem.

I'm having the same problem. I was told that it may be the entire cluster that has to be replaced.

Mine Freaked out like that when the Positive Terminal in the battery was about to fall out. When was the last time you changed your Battery????

I've had a similar issue and found that both terminals to the battery were corroded and missing some threads. Replaced the bolts ($2 at autozone) and everything was fine.

I'd also check your grounds too as mentioned. I found a loose ground at the firewall, but that was before I replaced the battery terminals. So it might have been an issue, but we'll never know.