temp. sending unit issues

1989 FORD MUSTANG

62,500 MILES • V8 • 2WD • MANUAL

LAMBOSUPRA16

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i have an 89 mustang gt with the 5.0. i have a temp. issue according to the gauge. however, when i checked the temp sending unit next to injector 5 (pulled wire off, grounded it, turned on the ignition and watched the temp gauge skyrocket), it proved to b faulty. I replaced it twice, both times checking it b4 starting the car and after about 5 min of driving, they both failed. any ideas?

Apr 28, 2011 at 12:29 PM

CJ MEDEVAC

CAR REPAIR CONTRIBUTOR
11,004 POSTS

GROUNDING THE SENDER WIRE, BY-PASSES THE SENDER WITH "FULL GROUND".

THAT IS A TEST TO SEE IF THE GAUGE IS FAULTY....IT SHOULD PEG OUT...IT THINKS THAT THE SENDER IS SENDING IT A "FULL BLOWN OVERHEAT"!

ACTUALLY IT IS NOT READING ENGINE TEMP AT ALL, WHEN YOU "JUST GROUND IT"

YOUR QUESTION IS SORTA.......NOT SPECIFIC

IS IT OVER HEATING?

DOES GAUGE READ THE SENDING UNIT AT ALL?

AT THE END??? BOTH WHAT FAILED???

KINDA START OVER (PLEASE!)--WHAT WAS INITIAL PROBLEM?--HOW DID YOU DIAGNOSE THE PROBLEM?--THEN YOU REPLACED SENDER???

.........BIG QUESTION, HOW ARE YOU TESTING IT TO DETERMINE IT IS FAULTY? AFTER IT'S IN???...WHAT'S IT DOING OR NOT DOING?

REMEMBER--GROUNDING THE SENDER WIRE, ONLY TELLS YOU THE GAUGE WILL LIFT OFF OF THE BOTTOM AND MAX OUT.

HAD IT NOT MOVED, YOU WOULD EITHER HAVE A FAULTY GAUGE OR THE WIRING/ WIRE COMPONENTS FROM SENDER TO THE GAUGE MAY BE "OPEN" (BROKE/ SHORTED/ FUSE BLOWN)

WE TRY TO HELP, NOT DEGRADE YOU!

JUST NEED MORE/ BETTER INFO TO UNDERSTAND YOUR SITUATION, KINDA SEEMED LIKE YOU WERE IN A HURRY, SENDING IT...WE LIKE MEGA DETAIL, HISTORY, WHATS BEEN DONE....MODIFICATIONS FROM OEM.

THE MEDIC

Apr 28, 2011 at 8:31 PM

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