overheating 2000 malibu

[TexasT]

Daughters 2k Malibu was overheating. We swapped out the intake gaskets. Stopped using coolant for a bit. Then we discovered the cooling fans weren't operating. $30 for a pair of new relays, operate for a while. Now not operating again. Jumped across the switch on each circuit. One circuit both fans run and other one fan runs fast. My research tells me the pcm controls when the fans turn on. Might be a bad temp switch but the dash gauge works.

I thought about wiring up a pair of switches so she can turn them on but that is a lot to remember to turn them off and not run the battery dead.

Any thoughts?

[larrym]

2 switchs 1 for the gauge one for fan.

[TexasT]

There is one near the intake with two(mayne three) wires. One down on the block in front with one wire.
Maybe the one wire One just creates ohms at a certain temp and has gone bad. Not sure how to test it. I tried disconnecting,  putting the meter from wire to ground but didn't see anything. Maybe I'm not doing it right.

[good2win22]

Pot of water on the stove along with a volt meter works for me when checking resistance for a water temp sending unit.
 
The two maybe 3 wire could be your switch that signals ECM for low speed and high speed fan.  Again I would think a pot of water on the stove along with a volt meter would let you know if the switch is able to close the circuit

[daveismissing]

what does the ECM say the temperature is?

[Pyro6]

Sometime it's just the connector. I usually watch the sensor on my scanner, jiggle the wire and see if it reads all over the place.

[TexasT]

I plugged in the autoxray but I don't remember what the temp was. She went back to school, so it is several hours away. I equipped her with three gallons of coolant and a plastic crate to keep them upright in the trunk. She was able to get the fans working last time with a pair of relays. Maybe they went bad again. I'll add when she calls or brings it back.

Thanks for the input.

[TexasT]

Sadly this car ended up on the side of i45 so we had it towed to her apartment. I went down and got it on the trailer. We goffed with it some more. Put a set of rings in it and the next daughter ran it until it ended up on the side of i20. Much closet to the house so I got it started and drove it home. Did the top gaskets again but it was knocking so bad when I got done we bought a $300 engine from The wrecking yard. Got it in there and am hooking the stuff back up. It is a clean little car. If I could get them to check the oil and coolant it would surely last longer . Oh well.

So I'm hooking stuff up. I should have known by the color but didn't even notice. I put the O2 in there. Tried to hook it up to the plug. Nope. Two notches in the plug, one notch in the o2 sensor plug. Out it comes and in goes the old sensor from the busted engine.





Why does everything need to have different stuff?

[earlbrown]

If it's just a beater car, I'd get one of those cheep $20 cooling fan temp switches for aftermarket fan installs.

Wire it parallel that way if the cars factory stuff is flaking out, the cheep switch will get on the clock and take care of business while idling.

[daveismissing]

A relay wired to the switched ignition should save the battery

[TexasT]

I got a $15 fan setup off eBay. Has the temp switch a relay and some wiring. Gotta figure out where to screw it into the engine and wire it up. I bought a thing that could go inline in the radiator hose but the threaded part isn't big enough threads for the switch to screw into. Only $4 so it was worth a shot .
On the up side i watched a vid on how to bypass the antitheft on the 03 cavalier we have been having probe with. It has been not starting. The fuel pump wouldn't run. It would just crank over. Pulled the plastic cover off the steering column and clipped a wire. Now it starts every time so far. Downside the antitheft light on the dash stays on. Fixed that with a well placed piece of electrical tape.

[earlbrown]

I remember when my young neighbor walked over and asked what I was doing...  Told him I was turning off my 'check engine light'....   then handed him the bulb.