How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Randall C Your Own Question
Randall C
Randall C, ASE MasterTechnician
Category: Ford
Satisfied Customers: 12890
Experience:  35 years ASE Master Tech, Diagnostic , Electrical Specialist
13677702
Type Your Ford Question Here...
Randall C is online now
A new question is answered every 9 seconds

1997 FORD ECONOLINE: temp gauge..HAVE REPLACED SENSOR, CLUSTER..ecU.

Customer Question

1997 FORD ECONOLINE 350 TEMP GAUGE INOP. HAVE REPLACED SENSOR, CLUSTER, AND ECU. STILL DOES NOT WORK. WIRING CHECKS GOOD. PLEASE HELP
Submitted: 6 years ago.
Category: Ford
Expert:  Randall C replied 6 years ago.

Tracer :

Hello, My name is Randall. I will do my best to assist you with your question

Tracer :

There are 3 different coolant temp sensors. I need to know what one you replaced and the wire colors going to it. LMk thanks

JACUSTOMER-g2kxyv68- :

TOP FRONT OF ENGINE. colors are red with white tracer. and yellow with red tracer

Tracer :

You have checked continuity of the R/W wire right to the cluster and know there are no breaks correct or have not checked yet

Tracer :

What is temp needle doing? on bottom, maxed out?

Customer: replied 6 years ago.
no brakes in the wire. gauge is sitting on the bottom. i can ground the wire and gauge will go to top. service info says i should have 5 volts on cuircuit. i have 12 volts coming out of new and old cluster
Expert:  Randall C replied 6 years ago.
Are you grounding the R/W wire? correct?
Customer: replied 6 years ago.
yes
Expert:  Randall C replied 6 years ago.
Ok , pleae do not take this the wrong way :) Either you engine temp is so low that the guage is not reading OR you have a faulty sensor OR your Y/R wire is not grounded. It cant be anything else

The R/W goes direct to cluster. Forget the PCM as it is NOT part of the temp guage circuit per say. yes, the R/W wire Does go off to PCM but branch separate to the guage. Your guage works, R/W wire is good, So... this would tell me the Y/R wire is not grounded.

I would poke through the Y/R wire and jump artificial wire to ground. If it still does NOT work. 100% you have bad sensor or enginetemp is really that low.

Here are the diagrams. Look close at DIAGRAM #2 as you will see the feeds of R/W and Y/R. Y/R goes to ground