2-wire coolant temperature Sensor and

[daniauction]

Can someone tell me where can I get this coolant temperature sensor? It's for a Cat 3126.
Thank You

 

[Ronmar]

Need year and model truck, and there should be a label on the wire harness near this sensor’s connector? Also need to know EXACTLY where it is installed… I suspect this is an early A1 and that is the 230F high coolant temp idiot light switch installed in the thermostat housing… yes, most definitely NOT a cat part…

 

[daniauction]

Need year and model truck, and there should be a label on the wire harness near this sensor’s connector? Also need to know EXACTLY where it is installed… I suspect this is an early A1 and that is the 230F high coolant temp idiot light switch installed in the thermostat housing… yes, most definitely NOT a cat part…

Hello @Ronmar appreciate your help
The truck is a M1085 A1 from 1999
The label is very difficult to read but I can see is first row 1242 may have more numbers Second row 78280
It's at the right side of the engine and to the front See attached pic for location

 

[Ronmar]

I was referring to the cable tag. Out near the electrical plug on either the sensor or the truck side of the plug. There should be a aluminum tag that has the plug or jack number P?? or J?? so we can identify the circuit. based on this second photo it may indeed be the idiot light sw.

i suspect you have what i call an A0.5, which is basically an A0 truck with the 3126 engine. Do you have an ether bottle behind the cab? If so that sensor could also be the ether enable temp switch(disables ether above a certain coolant temp).

Is there anything on the other side of the thermostat housing(inboard side) from the sensor seen in this latest picture?

Does yours have an intake heater(if so it will have a large relay near the left rear corner of the cylinder head) I suspect not if it has ether...

 

[Ronmar]

The more I look at it the more I am thinking, that is the ether high temp cutout sw... which probably means the cable tag will indicate P42. if there is no tag, if you unwrap the wires on the truck side of the connector you will probably find wire numbers 1402 and 1403 stamper on the wires...

 

[GeneralDisorder]

All of the 3126 and C7 trucks have intake grid heaters AND ether. 3126 has a manual ether switch. C7 is entirely computer controlled.

 

[daniauction]

I was referring to the cable tag. Out near the electrical plug on either the sensor or the truck side of the plug. There should be a aluminum tag that has the plug or jack number P?? or J?? so we can identify the circuit. based on this second photo it may indeed be the idiot light sw.

i suspect you have what i call an A0.5, which is basically an A0 truck with the 3126 engine. Do you have an ether bottle behind the cab? If so that sensor could also be the ether enable temp switch(disables ether above a certain coolant temp).

Is there anything on the other side of the thermostat housing(inboard side) from the sensor seen in this latest picture?

Does yours have an intake heater(if so it will have a large relay near the left rear corner of the cylinder head) I suspect not if it has ether...

The cable says (125 C 600 V AWM 46017) No aluminum Tag
The body of the sensor says (100 48T31 32445 L100-30F 89936

See attached picture for location

 

[Ronmar]

the first set of numbers denotes the wire specs on the wire used on the sensor, 125C thermal rating, 600V insulation rating AWM is the wire type and 46017 is probably the manufacturers cage code.

The second set of numbers looks like the sensor part number info, i suspect 30F is the temp rating/switchpoint and the last 5 digits the manufacturers' cage code... This switch disables the the ether start switch circuit if the coolant temp is above 30F. mine on my A0 cutoff ether at 35F.

if you follow that wire back to the electrical plug, where it connects to the truck wiring harness, I suspect you will probably find the truck side wires at the plug covered by wire loom material and electrical tape. if you open that up you will find wire numbers stamped on the, most likely white, insulated individual wires running to the truck side of the plug...

Why are you interested in this sensor anyway? Is it damaged in some fashion?

 

[daniauction]

The engine does not raise temperature even 1/2 hour running, ( I already change the temperature gauge) I thought this was the temperature sensor so I removed it and when I reinstalled it it broke

 

[Ronmar]

The gauge temp sensor should be on a T fitting on the rear of that housing where this switch is located(To the left in that last pic). There should be another switch(230F high coolant switch) on the inboard side of the yellow thermostat housing, directly opposite the switch in your last pic.

the gauge temp sensor is a 1 wire common automotive sensor. The gauge measures current flow thru the sensor. Unplug the wire off of the sensor and jumper it to ground. In the cab turn on the ignition switch briefly while watching the temp gauge it should move toward hot. If it does, the sensor is the issue, if it does not, the wiring or gauge is the issue…

 

[GeneralDisorder]

Did you put it under load? Diesel engines are notoriously cold blooded. You can also put it in gear, chock the wheels, and engage high idle. That will bring it up against the thermostats and should show temp on the dash.

 

[daniauction]

Did you put it under load? Diesel engines are notoriously cold blooded. You can also put it in gear, chock the wheels, and engage high idle. That will bring it up against the thermostats and should show temp on the dash.

I will try it
Thank you

 

[daniauction]

The gauge temp sensor should be on a T fitting on the rear of that housing where this switch is located(To the left in that last pic). There should be another switch(230F high coolant switch) on the inboard side of the yellow thermostat housing, directly opposite the switch in your last pic.

the gauge temp sensor is a 1 wire common automotive sensor. The gauge measures current flow thru the sensor. Unplug the wire off of the sensor and jumper it to ground. In the cab turn on the ignition switch briefly while watching the temp gauge it should move toward hot. If it does, the sensor is the issue, if it does not, the wiring or gauge is the issue…

Ok I will check it , but how abut this sensor where can I find it?

 

[Ronmar]

The sole purpose of that switch is to disable the ether dash switch when the coolant is a little above freezing. mine opens above ~35F.

The original P/N out of the 24P manual for the A0 is QS-1190-2SS, specified by the manufacturer of the Ether start system, Quick Start. I don't think they are in business anymore/sold out to someone else . At any rate googling that number gets me returns for switches at eastern and midwest, but both appear out of stock. it also popped a return for a switch on Ebay with spade terminals that linked it to an Oshkosh part with a QS1190-2... The SS may have denoted a special switch for Stewart and stevenson as most ether kits do not even have a thermal switch in circuit.

At any rate you could also substitute it with any normally closed switch that fits the pipe thread opening and opens ~35-40F to disable the system. You could put a pipe plug in the hole, and cut the leads for the old switch and splice them together, which would make the ether switch live all the time. you could also alter the power to the ether system so it only receives power when cranking which would keep the ether dash switch disabled most of the time?

OSHKOSH THERMOSTATIC SWITCH 3626591 2AN391 QUICK START QS1190-2 | eBay

S/H TO ANYWHERE.

www.ebay.com

 

[GeneralDisorder]

Just bypass it and don't use the ether when it's contra-indicated. Pretty simple IMO. Don't be an idiot PV2 and start pressing buttons you haven't been trained on. Might eject the warp core. Get busted down to mosquito wings.

 

[daniauction]

The sole purpose of that switch is to disable the ether dash switch when the coolant is a little above freezing. mine opens above ~35F.

The original P/N out of the 24P manual for the A0 is QS-1190-2SS, specified by the manufacturer of the Ether start system, Quick Start. I don't think they are in business anymore/sold out to someone else . At any rate googling that number gets me returns for switches at eastern and midwest, but both appear out of stock. it also popped a return for a switch on Ebay with spade terminals that linked it to an Oshkosh part with a QS1190-2... The SS may have denoted a special switch for Stewart and stevenson as most ether kits do not even have a thermal switch in circuit.

At any rate you could also substitute it with any normally closed switch that fits the pipe thread opening and opens ~35-40F to disable the system. You could put a pipe plug in the hole, and cut the leads for the old switch and splice them together, which would make the ether switch live all the time. you could also alter the power to the ether system so it only receives power when cranking which would keep the ether dash switch disabled most of the time?

OSHKOSH THERMOSTATIC SWITCH 3626591 2AN391 QUICK START QS1190-2 | eBay

S/H TO ANYWHERE.

www.ebay.com

@Ronmar Thank you so much.