Xdt Posted March 15, 2015 Share Posted March 15, 2015 Hello, Recently purchased an 87 4.0 4WD 5speed. Unknowingly the truck has some wiring issues, which I am finding out is quite common. I have the service manuals for both an 87 and 88 however I cannot find the connections for the attached items. Please help identify the correct wiring for the 2 relays and 2 vacuum ports. Better yet are these items factory and do they belong? Also the schematic shows that a green wire with trace should attach to one of the terminals on the evaporator switch, any idea of where the green wire w trace originates? Link to comment Share on other sites More sharing options...
cruiser54 Posted March 15, 2015 Share Posted March 15, 2015 That's not original. as for electrical issues, click on the link in my signature and do Tips 1 through 5, and 27 would be even better than 2. Link to comment Share on other sites More sharing options...
Xdt Posted March 15, 2015 Author Share Posted March 15, 2015 Cruiser 54, Thank you for the reply, I have your tutorial, as a matter of fact I purchased the upgraded power and ground kit from "kellyswip" as referenced. Very nice kit and Kelly is extremely helpful and knowledgeable. Tips 1-5 have been performed, 27 is on the list. If the relays and vacuum ports are not original, please advise of the schematic that will show the correct ac/heater vacuum routing? Link to comment Share on other sites More sharing options...
cruiser54 Posted March 15, 2015 Share Posted March 15, 2015 I am not computer literate enough to post photos here. click on my Tech Photos link below and scroll through. Link to comment Share on other sites More sharing options...
Xdt Posted March 16, 2015 Author Share Posted March 16, 2015 Cruiser, I found the vacuum diaghram, thank you again for the assistance. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 16, 2015 Share Posted March 16, 2015 Hope it helps. see Tip 22 if you need the harnesses. Link to comment Share on other sites More sharing options...
Xdt Posted March 17, 2015 Author Share Posted March 17, 2015 Cruiser, The port for the outside air valve on my AC control vacuum control system is blocked from the factory (no opening for a hose). Since the entire system works off vacuum can I splice into either of the open ports to provide vacuum to the outside air valve/ (recirc door)? As long as each valve is provided vacuum how critical is the source? Also as for tip 22 I can check that one off the list, ordered the parts from NAPA and installed them. I am taking your advice just a little slow getting there. Thanks again for the help Link to comment Share on other sites More sharing options...
cruiser54 Posted March 17, 2015 Share Posted March 17, 2015 I'm confused about the vacuum thing. Perhaps a Factory service Manual with the HVAC diagram would be useful? Link to comment Share on other sites More sharing options...
Xdt Posted March 17, 2015 Author Share Posted March 17, 2015 Cruiser54, Please reference the AC schematic, the vacuum hose connections on my truck do not match the diagram verbatim. On my truck the orange hose from the recirc door is missing and the number 7 vacuum port is occupied by the blue hose from the floor door valve. Also my number 8 port is block from the factory, therefore I have one less port than what the schematic shows. My question is does it matter where I tie in the vacuum connection for the orange recirc door hose, since the entire system works of vacuum? Link to comment Share on other sites More sharing options...
cruiser54 Posted March 17, 2015 Share Posted March 17, 2015 Being as I've been troubleshooting an electric dryer tonight under pressure from my wife, and haven't found the issue yet, my brain is fried. If you're concerned about a vacuum SOURCE for the controls, any source is fine as long as it has storage capabilities like the factory one inside the passenger side front bumper. Link to comment Share on other sites More sharing options...
Xdt Posted March 18, 2015 Author Share Posted March 18, 2015 Cruiser54, Thank you and good luck with the dryer. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 18, 2015 Share Posted March 18, 2015 Cruiser54, Thank you and good luck with the dryer. Funny story on the dryer. Self diagnostics mode revealed no issues. So, I began testing components with an ohmmeter per the tech sheet. Everything passed so far. Got down to a switch which shuts the power off to the motor if the belt breaks. Tested it and it passed. That left the $325 control board as the last thing and it's not testable. Plugged the dryer in and it worked!! Sound like a REnix? R*C*B*R*C Link to comment Share on other sites More sharing options...
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