Strange behavior. I don't see a relay, but the components have logic circuitry. Not sure why--bad design. What I would do is test the dimmer. Unplug the connector and put an ohmmeter across the yellow and gray wires (terminals S and J). Ohms should go from infinity to zero as you rotate the dimmer knob.
http://bbbind.com/free_tsb.html free wiring diagrams . Enter your vehicle info . year , make , model an engine size . Then under system click on interior an driver amenity , then under subsystem click on audio ,then click on search an four links will pop up . Click on them one at a time till you find the one your looking for !
Make sure you have the right size belt. If it's old then replace it. Then make sure you run it correctly or it can slip off. If it still slips off then check all your pulleys for chips or wobble before you replace any pulleys. I hope this will be some simple help for you.
A vacuum leak somewhere, or a tranny modulator, or both. Mechanic can do a vacuum test, or you can buy the vacuum meter and do it yourself. transmissin modulator (if your car uses one, that is) is located on the outside of the tranny and looks like a frisbee-shaped disk about the size of the base of a water glass, made of aluminum, and has a vacuum hose attached. buy at a parts store. (I'm betting on a vacuum leak, though)
If your check engine light is on you should have it checked for DTC'S - diagnostic trouble codes ! An there is no SECURITY light lit on the instrument cluster ? In the underhood fuse / relay box is the CRANK RLY , this relay energizes the starter ! If you pull the relay out of it's socket you'll see four terminals or pin's what ever you like . You'll also see four numbers 85-86, 30-87 . 30 an 87 are the starter side circuit . 30 should have battery voltage if tested with voltmeter or a test light , 87 goes to the S terminal at the starter solenoid . 85 an 86 are the control side circuit , one should have battery voltage an the other is control from the PCM/ECM .If you can use a volt ohm meter you can see what is missing to further you diagnosis , voltage , control ! You mite want to do a voltage drop test of the starter circuit - battery cables ! Check fuse PCM/ABS 10amp left I/P fuse box an PCM (crank) fuse 10amp left I/P fuse box .If you haven't done this type of thing before you may want to take to a ASE certified repair shop ! Here I will post a video on relays ! VEHICLE RELAYS Operation Diagnosis
The security light is a visual indication that something in the car's antitheft system is failing. In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM. (Theft Deterrent Module) The TDM is what tells your computer that the correct key is being used and that it is "OK" to allow the vehicle to start and run. These 3 parts must be in CONSTANT communication. If the key is in the ignition, then these parts are sending important signals to each other. The security light illuminates when that signal gets broken, even just for a second. When the signal breaks, (normally due to a failing/broken part) the car goes into antitheft mode. The car misinterperates this and thinks its being stolen or hotwired because it is NOT getting that signal from YOUR specific key. There is where the security light turns on and shuts down your vehicle. So basically, if that light is on, your system has some sort of failing part. This can start as an intermittent "no start", to your vehicle not running for days at a time, to the vehicle NEVER starting again. The problem is electrical and computer based, so don't count on an easy reset button, or the problem fixing itself. The hard part is isolating which part is the problem. You can spend a thousand dollars through a mechanic very easily. I have had great luck with bypassing the entire system. This way the problem will never return. It actually CAN'T ever return because it is eliminated. This can also be done yourself at a much cheaper cost. Read through this link very carefully. You'll find alot of information and pictures, along with ways to help you fix this.