Help! My car is falling apart faster than I can fix it. I own a 97 Mazda 626 LX automatic w/overdrive and when I am slowing down under 40 mph the car jerks as it is switching gears The only way to avoid the lurch is to turn off the overdrive then it comes to a stop nicely. Also, where are the relay or relays that turn on the compressor on my A/C unit. I know about the one in the black box but I was told there were others. Help!

 

Jerk when slowing sounds to be a probable ailing transmission. The ATX in the 4 cylinder were a pretty weak link in the dependability of that year 626.
The only relay for the compressor is in the underdash fuse box if this is the black box you were referring to. Power for switching side of relay comes thru the 30A A/C relay, then to the relay itself, on to the thermal protector on the compressor and then finally to the compressor clutch coil. Can you hear or feel the relay click when the A/C is turned on?

 

The mechanic said that the compressor kicks on for a moment then goes back off. I cant hear anything when I try to turn on the A/C. I have looked at all the underdash fuses and under the hood is the little black box I am referrring to. I will look at them again in case I missed something. You referred to the 4 cyl but mine is a 6 cyl. Does the same pertain on my transmission?

 

The V6 transmission is much more reliable but still possibility off failing. A good transmission shop should be able to tell you much more as they can drive and do a quick diagnostic to possibly determine if is tranmission related. Still sounds like it from you description. The A/C is similar in the V6 as well. Only one relay in the underhood fuse/relay box labeled A/C control clutch operation. Three relays control operation of the condensor fan but should not affect compressor. Does the engine idle dip quite a bit when A/C kicks on and then off suddenly. A seizing compressor could be cause of this. Low or overfull freon charge could also cause only momentary compressor operation.