Help, I need somebody! Not just anybody but someone who knows 1992 PU Truck Electrical System. I need to know the name of the Electrical Unit attached to the rear of the fuse box. I understand that it is related to the Brake Lights as well as other electrical functions. Please, any HELP would be appreciated?

Question edited for clarity. Add Additional information to main question.

Ideas here. Drop into an Interstate Shop and get the battery checked for Volts and Cold Cranking Amps. It is free and takes 2 minutes.

https://www.google.com/search?q=1992+Chevrolet+truck+hard+start+when+cold

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try the auto section at your local library. some libraries have auto repair manuals, motorcycle repair manuals, airplane repair manual, transmission repair manuals, electrical system repair manuals. they will not let you check the manual out but you are welcome to make a copy of the pages you need.

Battery light is for the charging system not working , not the battery .
anybody had this issue? Don't look for magical fixes , what fixes someone else's vehicle may not fix yours . If you don't know how the thing's on your vehicle work ,your best bet , take it to a qualified repair shop. Testing the electrical circuits of the thing's not working is how you fix these type problems . Looking at a wiring diagram , using a DVOM - digital volt ohm meter an testing the electrical circuits.
Electric Testing Techniques You Need to Know

http://www.bbbind.com/free_tsb.html free wiring diagrams here !
Enter vehicle info. Year , make , model and engine size. Under system click on body & accessories then under subsystem click on something your having problems with . Then take apart what ever need's to ,to get at componets that need testing . Insturment cluster , door panel's to check door switches , window motors .
Plus GM vehicles had problems with insturment clusters from 2003 to 2006 . causing all kind of electrical problems .
If you have not or know not what i have said here , take it to a qualified repair shop.

Trucks sold in California have one sensor in front of the catalytic converter and one after the cat.
Everybody else has just the sensor in front of the cat.

You will need the wiring diagrams to troubleshoot this, we do not have them here at fixya, sorry. They can be bought used here if you would like

The cheapest thing you can do at this point in time is to flush it. The problem with that is unless it is power flushed thetorqueconverterwill remain full of cruddytransmissionfluid. Yes you can do it your self, it is generally messy as you need to jack the thing up and unbolt thetransmissionpan unless there is a drain on it some where and the drain the fluid, the unbolting of the pan spills it all over the place. You will need a new gasket and some gasket sealer, RTV or something better. Your choice. It probably would be to your benefit to try to take the warpage out of pan hold downs with a hammer, actually two, one to hammer the point where the bolts went through if that is how you had to deal with things things and the other to act as a dolly. A new filter because it never hurts to have one and what evertransmissionfluid is required.
And my suggestion would be to obtain some LUCAStransmissionadditive. I have had some interesting success with Lucas products to the point now when I perform atransmissionmaintenanceI automatically use it.

it should be located under the dash on the drivers side or close to the fuse box or under the pass side dash i hope this helps you

normally the square connetors are a TH 700r4 which are hydraulic and the square connector is for the tourqe converter lock up

the ignition electrical switch (not the key ignition switch) on the bottom of the steering colomn is probably the issue........You can find it by looking under the dash while turning the key you will see a rod moving back and forth. At the bottom of the rod is the switch.
Hope this helps!

hi my name is david the problem most likely is that you need some more refrigerant that makes the air cold thank you for letting me help