Hi and thank you so much!
Yes, you are right, I have a GEM (General Electric Module) and yes, the colors are the same. The interesting thing is that the Solenoid did not react at all when I manually grounded pin 1 (Grey/Black) as it did when I grounded pin 3. And finally, yes, I know I can do it manually, but I guess the engineer in me wants to have it running perfectly and also get the answer to what is actually wrong.

 

Short update: Got my new vacuum solenoid, installed it, test run, works and has worked ever since then (as of today, about three weeks).
Thanks for all support!

 

Hi everyone!
Final update on this thread from me. You can of course never be 100% sure, but I am 99% sure that in my case the solenoid was causing the problem.

 

I am interested in talking with anyone who has a problem with the ESOF. I am redesigning the hub seal, which is a cronic problem with the ESOF system. if you have any information, email me at david.rupp@federalmogul.com and I can try to help you

 

Thanks for all the info. I have done just about everything you did, and hoping its the Solenoid. I'll pick and new one up Monday and see.

 

Picked up a new Solenoid today ($54), put it on and everything seems to be working fine now. Hopefully that was it!!!

 

So would the defective solenoid cause the vacuum pump to run longer than normal?

 

I would think if a solenoid is bad that controls vacuum, that it would affect the vacuum pump. Just an opinion, cause I am far from knowledgeable when it comes to the vacuum on our trucks.