grifter95

My 05 GTO has been sitting for almost a month while I have been installing UPP twin turbos. Well got to the point last night where I needed to fire it up to finish adding coolant/water and check.oil level. Battery was relocated to trunk due to lack of engine bay room with 0 gauge wire. Put key in and turned and dash would dim when key turned. Figured battery was weak (6 yr old optima) so I attempted to jump start it with same results. So I took battery to Advanced where they checked it. Came up unstable/bad cell. So I bought new one and took it home and installed. Now here is what is happening;
Interior dome and door and under dash lights work
Key fob when clicked lock/unlock parking lights flash but locks don't operate
Put key in ignition and turn nothing happens.... I mean nothing dash doesn't even light up or radio power up. Only light in cluster that is lite is the car/lock red flashing icon. Has me baffled. I have rechecked ground connection (frame sanded to bare metal).

Any suggestions or ideas?

I have checked ALL dash/engine bay fuses... all good.

I am completely baffled.

grifter95

Rechecked all fuses this morning in the light... none are blown. Headlights, interior dome/door lights, parking lights all work. But nothing anywhere else (pwr seats,windows, mirrors). Putting in the key doss not cause the usual chimming when doors are open, and turning it does not cause instrument cluster to wake up or radio/clock to illuminate.

Could the computer be fried? Could the old battery having bad cell/unstable caused all of this? Seems if it had been a short some fuse would be blown.

Checked voltage at battery (12.66v) and at fuse box (12.38v) doesn't seem to be lack.of power.

Thought it might be antheft being stupid and went to check with HP tuners but must have ignition tuned on for HP to read and turning key obviously doesn't cause ignition to come on now.

Bad ignition switch? Bad computer? Short somewhere? Second bad battery? Anyone?

jmt455

Dumb question, but is the new battery fully charged?

__________________
1968 Pontiac GTO
1983 Pontiac Bonneville (G) wagon
2008 Pontiac G8 base

grifter95

I assume it did come fully charged. I checked its voltage and it was 12v+. Also charged it with 10 amps for 20-30 minutes with no change in results. How else should I check to make sure it is battery?

grifter95

Opened car tonight and all hazard lights, interior lights (except dash), and horns flashed until clicker on key fob was clicked unlock. So plenty is still working.... just nothing tied to ignition being switched on. My tuner friend thinks it could be a bad bcm? Maybe shorted when bad battery was misfiring? But he is only guessing. Would power seats usually work with key turned off? I would think so... but they are not working.
Still baffled... feeling helpless.

68OldGoat

Check out the Sticky on this site for a possible easy fix for the BCM Wiring harness...common problem with these cars. IMO I believe it has something to do with the BCM like your tuner buddy.

grifter95

Odd that relay audibly clicks when fob is pressed but actual locks do nothing?

grifter95

68OldGoat.... still new to this forum. Where would I find the sticky you suggested?

johni53

I'd take it to a GM dealer; know it'll be more expensive but at least you've got a better chance for the right diagnosis.

68OldGoat

Service, Maintenance and Technical Discussion - Pontiac GTO Forum