why would my trans mission downshift and rpms go sky high when iam driving down the road and put the heater or air on? also it dont blow hot or cold. The trans also has a high shift point for 3rd gear its around 3200 when heater is off. is there a vacum i can check? PLEASE help, thanks.

 

anythoughts??

 

bump. same thing is happening to my jeep. im a little confused, have just changed a few things on it and not sure where to start diagnosing it. Mainly i scraped the abs pump and replaced with a proportioning valve, while doing this my master cylinder seal broke and i have had vacuum leak problems coming from the brake booster.... needless to say i have fixed the vacuum leak on the brake booster but still the weird down shift with my heater turned on. so is it electrical and integrated into the wiring loom or apart of some other vacuum problem?? any thought would be appreciated. other notes, 1996 cherokee country 4.0 ford 9 d44 no abs. also heater fan will not blow either while heater is on and my cruise control has not worked since i wrecked it 3 years ago. thanks guys