WOT Relay Issue


hntr45

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So I'm not exactly sure if my issue is the WOT relay or TPS because I don't really know how the WOT relay is supposed to work...

Anyways, I have a 97 ford ranger 2.3. With the AC on, it is to my knowledge that the WOT relay will open when you give the truck a certain amount of throttle for climbing hills, passing, etc. The issue I am having is that I will floor it with the AC on and the compressor continues to cycle. I've even had it where I was going downhill and it wouldn't cycle, but when I would start to go back up the hill, the compressor would kick in like it's reading in reverse... Seems to me like it would be WOT relay because I do have an issue where the AC clutch will engage with the heat on, not on defrost... but I also think it could be the TPS since it has to read throttle position..

Any suggestions?
 


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RonD

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1997 Ranger WOT relay passes power to compressor's coil(clutch) when open(not powered).
Computer will power the WOT relay to cut power to the Compressor's coil

Power for the compressors' coil runs like this:

12volts---AC switch in dash---------pressure switch 1-----pressure switch 2-----WOT Relay(off)-----Compressor coil------Ground

So an open pressure switch or closed WOT relay(on) would cut power to compressor's coil

Not sure I understand your question completely.

Computer senses engine load from RPM, speed and TPS
TPS gets 5 volts from computer and sends back under 1v throttle close, then an increase in voltage as throttle opens.
Above 4.5v from TPS usually indicates WOT

First thing I would check is if throttle cable has stretched, common issue on Rangers.
Key off
Place a weight on the gas pedal to simulate WOT, or use stick against seat
Then check throttle at the engine and see if you can open it farther, if so then do "Throttle cable mod", google it, simple easy fix.

If you want to check TPS then get a volt meter and sewing pin
Key on - engine off
Use sewing pin to pierce center wire on TPS
Volt meter set for DC Volts
Ground meter and test voltage on center wire, .69-.99 should be seen, under 1volt, with throttle closed.
Slowly open throttle manually and watch voltage, should slowly climb up, no jumping or dropping of voltage.
At WOT it should be above 4.5volts
 
Last edited:

Ford123456

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I think I understood the problem hntr45 refered to, my Ranger does it as well. Have been wondering if there was a simple relay issue.
RonD your responce was to the point for any voltage and device tests i may need to do to check if this issue is caused by WOT relay.
Thanks to you both.
 

Ford123456

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So I'm not exactly sure if my issue is the WOT relay or TPS because I don't really know how the WOT relay is supposed to work...

Anyways, I have a 97 ford ranger 2.3. With the AC on, it is to my knowledge that the WOT relay will open when you give the truck a certain amount of throttle for climbing hills, passing, etc. The issue I am having is that I will floor it with the AC on and the compressor continues to cycle. I've even had it where I was going downhill and it wouldn't cycle, but when I would start to go back up the hill, the compressor would kick in like it's reading in reverse... Seems to me like it would be WOT relay because I do have an issue where the AC clutch will engage with the heat on, not on defrost... but I also think it could be the TPS since it has to read throttle position..

Any suggestions?
curious if you found the solution to your upside-down A/C clutch operation..
 


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