I just got a call from the customer and it isn't a chrysler it is a '98 Plymouth Voyager with a 3.3 liter engine.
My problem is that when she first brought the van to me its cooling fans would not turn off and the water pump was leaking so I replaced the water pump, coolant temp sensor, and the thermostat. Now the fans won't engage at all and I have checked all of the fuses and relays and they are fine. Could it be that I have installed a defective coolant temp switch? Somone Please Give Me A Professional Opinion. I have been an auto tech for 8 yrs. and I'm pretty much stumped on this one.
2006-06-13 10:41:12 · 5 answers · asked by catmanbigwil 4 in Cars & Transportation ➔ Maintenance & Repairs
most likely you got a bad switch if you have the old one try and you,ll know
2006-06-13 10:47:28 · answer #1 · answered by carman fixer 1 · 0⤊ 0⤋
Totally agree with the above posts and add a couple more things to check:
1. Test the temp sending unit independently of the system (using a test light or similar) as described above.
2. Test the fan relay. Is it turning on (getting power from ECM) on the control side? if so, maybe the relay points (load side) are pitted or dirty?
3. Test the fan itself - disconect and apply 12V DC to the fan (bench test)
4. Go back and re-visit the stupid stuff like:
a. Are you sure that only one temp sending unit is used on this model - or that you swapped the right one? For some reason I was thinking that the some of those models had a seperate temp sending unit that only controlled the temp guage on the dash and an aditional sending unit for the fan.
b. Check the wires and connections and for loose/missing ground straps etc.
Good Luck Bud, we've all been there!
2006-06-13 19:38:23 · answer #2 · answered by Saturday Morning 3 · 0⤊ 0⤋
Are the fans in operational condition? The relay is grounded by the computer. There could be corrosion on the plug to the computer, a cut wire, or a defective computer. You can bypass this by just wiring the relay up to the ignition or control the relay with a temp control device.
2006-06-13 17:47:43 · answer #3 · answered by jeff s 5 · 0⤊ 0⤋
I would try something simple, like putting a test light to the switch and let the car run. I would assume the light would go off when the car reached opp. temp. I could be wrong though.
2006-06-13 17:48:00 · answer #4 · answered by rolandrx7 3 · 0⤊ 0⤋
I would jump power directly to the fan, bypassing the switch and relay and see if the fan still works.
Then I would jump before the relay to see if the switch works.
That is how I diagnose em'.
2006-06-13 17:46:31 · answer #5 · answered by wixthedog 2 · 0⤊ 0⤋