1988 2.8 cooling fan circuit

[papawhellie]

Trying to get my cooling fan thermostatically controlled. I grounded the green relay wire so it runs all the time. Looking at the thermostat housing the sensor there has two wires. Seems maybe another sensor deeper down. The standard motor products item i ordered is a one wire connection. Can someone steer me to the part numbers to replace the parts to get my fan cycling. There is a one wire sensor in the radiator. My cutless cruiser is light not gauge and it does not work, not evening lighting with key on before start. My 2.8 has the old style induction with the round breather can.

[tlc1976]

The sensor in the back of the thermostat housing is what controls it. It sends the signal for engine temp to the computer, then the computer decides to tell the fan relay to turn on the fan. It has a 2 wire receptacle, is bigger around and short and stubby. Standard Motor Products TX3 looks like it.

The sensor you see deeper down in the driver side top of the intake manifold is most likely an oil pressure sensor/sender. For 1987/88 they used this along with the one next to the oil filter. For 1989 they eliminated the top one and the sender by the filter does it all.

The 1 wire sensor in the radiator on the passenger side is for the low coolant light in the dash. It's not tied to anything else but the dash light.

Then the sensor in the back drivers side corner of the head is for the temperature gauge/light, and is not tied to anything else either. That one has a long 1 or 2 wire pigtail with connector and is long and thin.

[tlc1976]

As far as the temperature light, I would first unplug the pigtail of the temp sender on the driver side back corner of the head. Try ignition at run. Then try connecting the car wiring at the sender to ground and try ignition at run. One of these (likely #2) will light the bulb. If neither does then change the bulb. But if the bulb does light during this test and you are sure the car is near overheating and the light still does not come on then change the sender.

[papawhellie]

Thanks so much. I ordered the ts 147 which rockauto list as radiator fan switch which is a single wire sensor and seems to be the radiator sensor. I will get the other ones on the way. Any thoughts on an easy access spot on the engine to install the probe for an aftermarket temp guage? I might use one of those glowshift products to access the hose though i hate to drop that 25 bucks. Its looks like a quick method. Oh look cheaper.

Dewhel Aluminum Blue Water Temp Meter Temperature Gauge Joint Pipe Radiator Sensor Adaptor Clamps 34mm https://www.amazon.com/dp/B00LVRZG14..._oVU1Db42R16J8

[tlc1976]

I was thinking something like the amazon thing. Sounds like the easiest and best way to go.