# A/C Compressor Lockup Keeps Car From Starting **URL:** \ **Category:** General Discussion\ **Created:** [May 1, 2018, 9:15pm UTC](https://community.cartalk.com/t/a-c-compressor-lockup-keeps-car-from-starting/116604 "2018-05-01T21:15:21Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Marnet](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/marnet/32/41_2.png) [@Marnet](https://community.cartalk.com/u/Marnet)\ **Post date:** [May 1, 2018, 9:15pm UTC](https://community.cartalk.com/t/a-c-compressor-lockup-keeps-car-from-starting/116604/1 "2018-05-01T21:15:21Z")
Curious to understand why a failed a/c compressor that locked up prevents a car from starting? Happened to a friend’s 2001 PT Cruiser. She thought it was a bad battery. But the shop she had the car towed to determined the battery and alternator are good. But the a/c compressor that was known to be failing totally locked up and once it did the car wouldn’t start even with a jump start. (I’m the one who tried giving her a jump. First time I’ve ever used my late dad’s jumper cables. 😀) The mechanic at the shop my friend used didn’t explain why/how the locked up compressor prevented the car from starting. Both she and I are curious to know (despite her husband opining that women don’t need to know such things. _eye roll_) ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [May 1, 2018, 9:21pm UTC](https://community.cartalk.com/t/a-c-compressor-lockup-keeps-car-from-starting/116604/2 "2018-05-01T21:21:22Z")
> [@Marnet](#): > > (I’m the one who tried giving her a jump. Marnet , that is something I will not do anymore. The chance of damage to expensive electrical parts is just too great . A road side service with a battery pack is about 25.00 and that is what I do. The other part is that the AC pump was locked and the serpentine belt just would not every thing turn and if it had started the belt would have fried in a heart beat. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [May 1, 2018, 9:23pm UTC](https://community.cartalk.com/t/a-c-compressor-lockup-keeps-car-from-starting/116604/3 "2018-05-01T21:23:14Z")
There is a big belt wrapped around all the accessories on the engine and driven BY the engine. If the compressor and its clutch lock up solid, that belt won’t move when that little starter motor tries to turn the engine to start it. If it DID start, it would squeal like a 500 lb hog and smoke like a tire fire! ---
**Author:** ![Marnet](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/marnet/32/41_2.png) [@Marnet](https://community.cartalk.com/u/Marnet)\ **Post date:** [May 1, 2018, 9:28pm UTC](https://community.cartalk.com/t/a-c-compressor-lockup-keeps-car-from-starting/116604/4 "2018-05-01T21:28:55Z")
Ah, didn’t realize the serpentine belt would be involved. Now it makes sense. I admit I was very unhappy about using my car as the “jump donor” and think I just won’t again. I stopped by my mechanic shop today to ask if I damaged my car. As everything on my car is working fine since attempting the jump the answer is likely not. But they suggested I can make an appointment to double check everthing if I want. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [May 2, 2018, 2:20am UTC](https://community.cartalk.com/t/a-c-compressor-lockup-keeps-car-from-starting/116604/5 "2018-05-02T02:20:17Z")
Your title says the “condenser” locked up. Did you mean the “compressor”? The condenser is sort of like those coils of tubes at the bottom of your fridge. You know, the ones that are really awkward to clean? That part could clog up, but lock-up wouldn’t normally apply to the _condenser_. The _compressor_ is the part the engine turns via the serpentine belt. If the _compressor_ locked up, it could prevent the engine from rotating and therefore it wouldn’t start. ---
**Author:** ![Marnet](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/marnet/32/41_2.png) [@Marnet](https://community.cartalk.com/u/Marnet)\ **Post date:** [May 2, 2018, 2:36am UTC](https://community.cartalk.com/t/a-c-compressor-lockup-keeps-car-from-starting/116604/6 "2018-05-02T02:36:51Z")
George, yes, you are correct. My error. I’ll see if I can edit both the post title and in my OP. Thank you for bringing it to my attention. 😀