HELP!!! Horn blows when cranking.

patruck · October 20, 2005

My friend owns a 2000 GMC Sierra with about 60k miles. Today, the truck would not start, and turned out he needed to replace the battery (it was leaking), so he did. The problem now is that when he cranks the truck, somehow the security system is tripped and the horn blows instead of the car actually cranking. Got any ideas? Your help will be greatly appreciated. Thanks!

GM-Tech · October 20, 2005

This is the factory content theft deterrant? And before you say yes, make absolutely, positively sure. Can't tell you how many people assume their alarm is factory because they bought the vehicle from the dealer that way. In fact, the dealer had installed an aftemarket alarm.

patruck · October 21, 2005

Thanks for responding. The alarm was aftermarket, and he was able to fix the problem by finding the remote (which he never uses), and using it to reset the system. Thanks again!

GM-Tech · October 22, 2005

Thanks for responding. The alarm was aftermarket

I thought so. These always give us trouble in service when we have to disconnect a battery for some reason and the customer didn't give us the remote. These tend to arm on a battery reconnect.