Fast Idle using cruise control

[95REDRAM]

Saw a post on this topic a while back but can't find it now. Have a few comments and questions.



My truck: 95 Ram, CTD, 5-speed, 4X4



The post I saw recently talked about a fast idle accessory available for the 24 valve engines. There was also information about using the cruise control as a fast idle for the 12 valve engines. Per that info I researched my factory manual and tried what the post said which was basically apply a signal to the vacuum port on the servo unit. The particulars I have tried are as follows.



1. At idle with the cruise control switch "on" there should be a battery voltage signal (i. e. app +12V DC) at pin 2 of the cruise control servo unit. This checks OK.



2. Circuit V36 supplies the vacuum "signal" to the servo unit. According to the PCM system schematic, this circuit V36 is actually making the ground for the vacuum "signal. " This is the ground for a solenoid that supplies vacuum to the servo unit.



3. I installed a momentary switch in parallel with the PCM for circuit V36. Actuating the switch does nothing. My cruise still works fine on the road so I didn't break anything when I made the modification.



In the post I read, the person who wrote in said he had tried this procedure and it worked. Do I have my information correct? Am I missing something here?



As I figure it from the PCM schematic, the DUMP solenoid is normally open and the vacuum and vent solenoids are normally closed.



Let me know what you think and if I'm missing something here.



Thanks guys!!!

 

[illflem]

You're right, the thread about modifying the cruise is gone. What I tried that worked was to apply 12v + to the servo up terminal, it increased the rpm much to fast but worked. I did it with the connector to the PCM removed. If it didn't work for you it could be that the brake/clutch signal from the PCM is venting the servo, try using your switch with the PCM out of the circuit.