Chrysler Repair: Grand Voyager 3.8 overheating, resistance measurements, voyager 3

Question
QUESTION: Hi

I have browsed the net and found many posts on this area. My 1998 AWD started having overheating problems in that the water would shoot out of the expansion tank! This was seldom though and I could not trace why. The other day when I stopped and turned the engine off, the fans kept running and the only way I could switch them off was by disconnecting the battery. To my dismay, when I connected the battery again hours later, the fans came on!? Fortunately they went off again after a while.

This time though when I started the car and let it run, the fans did not come on to cool the radiator. I also have no AC coolant so I could not test the fans using the AC. I did track from reading many posts over the web, that this pointed to the fan relay. I removed the old one (4707286AD Rev C) and purchased a new updated one (4707286AF Rev A). Unfortunately this did not fix the problem! Any suggestions?

I read that it could be an airlock, how do I make sure there is no air in the system? (The Voyager is the European equivalent of the Town and Country model).

I also read that it could be the temperature sensor and that this can be tested by reading resistance measurements at hot and cold. How do I do that?

I also understand it could be the fans. I read that you can shortcut the green/black cable to the black cable of the socket that goes into the fan relay. This did not bring the fans on. I did turn on the engine but the fans remained off. I presume this should turn the fans on immediately? I would really appreciate some advice on how to test the fans.

Any ideas of what I should do next would be greatly appreciated.

Thanks for any help
Ian

ANSWER: does the inside temp gauge show the temp??  if yes then u have a working sensor. U might have air in the system yes a coolant flush would take care of that. This is the updated part number for the relay 05017491AB. Did u mount it back to the frame rail? See if u get power to the relay. here is the pin out at the relay.

RADIATOR FAN RELAY (SOLID STATE) CAV CIRCUIT FUNCTION
1 Z1 14BK GROUND
2 K173 14LG/DB RADIATOR FAN RELAY CONTROL
3 C23 12DG RADIATOR FAN RELAY OUTPUT
4 A16 12GY FUSED B(+)


---------- FOLLOW-UP ----------

QUESTION: The temp gauge does work, but I wondered if there were a different sensor for the fan and that this may be faulty? How do I check that the sensor is reading the correct temp?

I have had the radiator of and refilled the rad, how do I ensure there is no air in the system?

Would the one I purchased (4707286AF Rev A) be alright? I did mount it on the frame.

How do I test the fans are working?


Thanks
Ian

Answer
only one sensor u get a infra red thermostat and point it on the sensor and see if the readings are close.
Not a drain and refill but a flush  where  vacuum is applied to the system and all coolant is sucked out and then filled back in 2.5 gal worth.
The one u got should be fine.
U will know if the fans work if u turn on the ac they come on in a matter of seconds.