We replaced the oxygen sensor in my 91 dodge ramcharger. Afterwards, the truck started up and ran for a while. Then we shut it off to reinstall the wheel which was removed. Now it will not start. The buzzer sounds, the horn blows, but when you turn the key to start it, it will not make a sound. We took the starter off, had it checked and was told it was froze up. Installed a new starter. Still nothing happens when you turn the key. We hooked it up to the battery charger, still nothing. Possibly some relay somewhere?