My a/c blower works only sometimes. Off and on.

Check every single other electrical accessory in your vehicle key on and off next time this happens, that will tell us whether or not it's the ignition switch. Could be a bad relay but only if it's happening on the highest setting only. The only way that motor can get power it's either when the key it's on our if that relay is closed. Could even be another relay under the hood depending on how the truck is wired.

I charged the battery, and the key came out. This is the 3rd time this has happened since I owned it since 2006. Very frustrating. Maybe something electrical? Thank you.

You never said anything about the key not coming out? Do you by any chance have an accessory position that you get by turning the key all they way backwards? My step moms blazer ignition switch is loose and sometimes is a pain to get it to the correct spot for removal.

A stuck key could also be a worn lock cylinder.

it goes into antitheft so the key gets stuck, and the gear shift stays in park only. the dealer said it might be the battery or the shift belt.

thank you

Also could be a loose battery terminal making better contact when you attach the jumper cables.

you are right the blower won't switch off, when the vehicle is off, even when I open the door it should stop, but does not. So how would I fix a relay from not sticking? I will get a new battery also, when I can afford it.

Do you have the original equipped autostart? Does the blower turn on when you use the autostart? If so this may be more than just a simple relay. If not then just replace the relay, its under the hood in a box usually labeled relay. It just unplugs by pulling straight out. The box will have a lid and on the inside of the lid there is a picture that maps out all the relays.

it does not have autostart. what relay? the starter relay?

no it will say blower or hvac, something along those lines.

ok, thanks again.

I have a 2005 Chevy Trailblazer my are just cut out well it was fading out then it wouldn't come back on now I just come back out to the car as I start driving the air comes back on but it's on low and only time the air comes on is when I'm driving if I'm sitting at light it cuts off do you know what the problem is

Sorry I mean my air cut off

I have replaced the resistor twice the last 12 months. just replaced it three weeks ago, now the blower quit again. it's getting expensive to have the resistor replace again.I don't know .what the answer , please help. thanks ed