what would cause cold advance sensor to keep failing..

[84cucv1ton]

not sure what would cause this.. any ideas what i should look for thanks

 

[Warthog]

Need more info. How is it failing?

Does it work for a while and then quit?

Not working at all?

Does it ever work properly?

 

[doghead]

Failing off, failing on, failing to operate at all?

 

[84cucv1ton]

OK sorry.. i put a few old ones in.. they keep failing. like to make sure all is ok before i put the new one in. 1 worked for a bit then failed thanks

 

[Warthog]

Are you talking about the cold advance that is inside the top cober of the injector pump, or the fast idle that pushes on the throttle lever? Or is the sensor on the side of the engine?

Is this the same issue you had last December?

http://www.steelsoldiers.com/cucv/79175-how-test-i-find-these-not-sure-what-there-called.html

If so did you check the voltage to make sure it was 12v and not something else?

 

[84cucv1ton]

one of these on the engine:
Amazon.com: ACDelco 10154649 Switch Assembly: Automotive

its getting 12v thanks

 

[84cucv1ton]

anyone

 

[Warthog]

Some of us do like to sleep every once in awhile.

 

[doghead]

If your solenoid has an internal short, it could burn out the sensor, maybe.

 

[84cucv1ton]

solenoid on top of the injection pump right?? yeah all need sleep

 

[Warthog]

The circuit that supplies 12v to the temp switch is hot as long as the key is on. It is circuit #39 in the diagrams.

The only load on the switch is the Fast Idle solenoid on the out side of the IP and the Cold Advance Control inside the IP.

If either one of these shorted in the could cause the switch to fail.

Or it could just be a bad batch of switches. Where did you buy the replacements?

Do you have a good multimeter that you can check resistance and amperage on the switch?

 

[84cucv1ton]

wow thanks.. very helpful. got the new one off amazon. yes i have a good multimeter

 

[Ken_86gt]

That part should be very reliable. I suppose a short as mentioned would be the likely reason for failure- an electrical overload. How did you test to determine that it is failed? It could just be a loose wire/bad connection making you think that it is failed.

 

[84cucv1ton]

I didn't test. I have some spare motors. I pulled them out of their. They would work for one or two startups that was it. Third or fourth time I would start truck it would not idle up.

Any idea what the the amperage should be? Thanks

 

[richingalveston]

check and ohm your wires

being that the sensor ads resistance when it gets hot, you may already have to much resistance due to corosion in the wires itself. Test the loop from the controler to the sensor and back to the controler. (not sure where it is but i belive this sensor comes from the glow plug controler)

someone here can correct me on the ends to test from.

If your wiring (being it is old) is breaking down, the wires can add enough resistance to cause the sensor loop to always be on.

I am not sure where the circuit originates and which is the return circuit. but if you test the loop, then bypass sensor and test loop again. the difference in the two readings should be the actual resistance in the wires themself. a loop this short with good wires should have almost no resistance.

Old wires can cause many problems when devices use resistance in the circuit to opperate.

also if your wires are grounding out due to bad insulation this will create similar issues.

the sensor itself may be going bad fast because it is getting grounded out burning the tiny wires on the sensor which probably act as fuses.