97 GTP Overheats

[sjdeades]

I recently acquired a 1997 GTP with higher mileage, the guy I got it from was frustrated with it so he was passing it on to me. He was having a problem with it overheating also. So I get it home and think it is just air in the system after he replaced lower intake gaskets, so I bleed the system and it took about 1.5 gallons of the green stuff. So I test drive it about 40 miles or so and no problems what so ever, so I am thinking. I drive it to work a couple days later and on the way it is all good. On the way home though different story, leave work 5 minutes into trip it overheats????? I think to myself what was different? I know the first two times I drove it I had the defrost on as it was cold out. I read that with the defrost on or the a/c running the electric cooling fan is running? So I just checked for power at the connector and I am not getting anything, but also when I tried to direct wire the fans, they did not run either or nor did they blow the fuse? I am at a loss I am assuming I can power the fans directly at the fan plug by applying ground and power, that is what I tried to do and they did not kick on. I have a wiring schematic from alldata, but it is a little confusing. Any pointers???? I had also had the dreaded blower motor only working on high, changed control module no change??? Is the cooling fan also powered off the electrical ignition switch in some way, I am thinking that may be the culprit. Just a little foggy on electrical stuff. Thanks in advance.

[Fivefingerdeathpunch]

maybe try a new thermostat??

as for the blower motor replace the resistor for it.

[sjdeades]

The thermostat is new, as well as the ECT sensor, and I did also replace the resistor and it only worked on high again. I am not sure how the thermostat would keep power from my electric cooling fans?

[Fivefingerdeathpunch]

thermostat does not have anything to do with eletrical stuff, it is just suppose to open at a certain temp 195*, 180* etc etc... depending on which one it is.

I am too kinda confuzzed as to why it overheated. and the fans not working.

[01gpgt01]

maybe the cooling fans are bad, If your running power and a ground to them and they dont turn on there shot

[stlmo_gtp]

or it's a fuse...that would be the first thing i would check (or atleast i think there is a fuse for the fans)

[KeithGTP03]

I ran across this when I had a 97. 1 week after I bought it, it would overheat intermittently. Took it back in, and the water pump was going out. Wont have anything to do with your fans tho.

[sjdeades]

I checked the two maxi fuses (30 amp) in the underhood electrical center, both good. I checked the leg labeled 85 on "cool fan relay 1", as schematic I have shows that should be hot all the time from fuse and I got nothing with test light. It shows the hot wire coming in through "cool fan 1 maxi fuse 30 amp" from the "power distribution cell 10" what that is I am not sure. Any suggestions? I see two wires coming from PCM that control Low and High Fan Speeds on schematic? Anyone.

[KeithGTP03]

Yeah, you need to tap into one of those lines and apply 12v's to it. Doesnt matter which one. I would tag the line right at the fan, to eliminate any fuse or relay issue. If you apply 12v right at the fan and it doesnt come on, you need a new one.

[KeithGTP03]

the hot wire coming in through "cool fan 1 maxi fuse 30 amp" from the "power distribution cell 10" what that is I am not sure.

The power distribution cell is a fancy name for fuse box. Prolly the one under the hood. "Cell 10" Im assuming is the number given to that fuse.

[sjdeades]

I changed the passenger side cooling fan motor as it was bad. It is still overheating and the driver side cooling fan will come on with the passenger side one at 250 degrees but does not come on at 210 degrees nor does the passenger side fan come on when I turn on the ac???? I have replaced the ect sensor and cleaned the wiring harness connectors at the ect end and the plug end right at the intake.... The car will go into dummy mode if you unplug the ect, starts dumping fuel and both fans come on.. I am leaning towards ignition switch issue, does that make me crazy???? Any ideas..... I have jacked the back of the car up and bleed the system for what seems like an eternity, I have good heat at all times so fairly confident it is not LIM or Headgaskets nor do I have any coolant in the oil.....