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    fusebox circuit diagrams?

    I'm looking for the circuit schematics for the board inside the fusebox. Specifically, the two different red boards. One's marked 004 and the other 006. With the diagrams I can see what's what and just rewire the car from the board I can't find (the 004 one) to the one I can find (the 006 one) and finally get my car back on the road. There are only a few pins that look different in the relay section so I don't anticipate it to be too difficult. I just need to know what's what before I start dicking around in there.

    **IF YOU HAVE A FUSEBOX WITH A RED BOARD MARKED 004 I WOULD LIKE TO PURCHASE IT FROM YOU, PLEASE PM ME**
    - Josh
    1990 325is

    Need a shift boot?
    Looking to buy shift boot frames, PM if you have one to sell

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    #2
    IIRC the big difference between the boards is what headlights the car was equipped with.
    -Dave
    2003 Lincoln Towncar | 1992 BMW 325iC | 1968 Cadillac Deville

    Need some help figuring out the ETM?

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      #3
      Car has sealed beams. So far I've come across two red boards and a green one. The green one is way different but the two reds appear to be identical except for 3 pins for the relays.
      - Josh
      1990 325is

      Need a shift boot?
      Looking to buy shift boot frames, PM if you have one to sell

      Here's what happens when you let the internet pick your license plate

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        #4
        Which relay pins are different?

        Post up a pic of the new board if you can, the one of your old board on your WTB thread is excellent btw.
        -Dave
        2003 Lincoln Towncar | 1992 BMW 325iC | 1968 Cadillac Deville

        Need some help figuring out the ETM?

        Comment


          #5
          I actually managed to finally find the appropriate board but I'll be keeping the extra as a spare for a while just in case. I have to find it and I'll post a pic but iirc the pins for K4 and K8 are different among with the jumper wire on the underside.

          I got everything back together already but the car still won't start. I'm thinking my failure may have extended into another component after K7. Any suggestions? I'm going to bring a test light out to the car tomorrow and see what I can come up with.

          Edit: that pic was taken with a nikon coolpix p5000 on macro mode. It came out better than I'd expected.
          - Josh
          1990 325is

          Need a shift boot?
          Looking to buy shift boot frames, PM if you have one to sell

          Here's what happens when you let the internet pick your license plate

          Comment


            #6
            K7 and anything associated with it should never interfere with the ability to start the car. Something else got screwed up. Does your ICV buzz with the key on?

            Also, just out of curiosity, still have your stock headlights? If not, the correct way to keep the lows on with the highs is cut the yellow wire where it comes out of K3, and use a ring terminal and attach it to the allen bolt.
            -Dave
            2003 Lincoln Towncar | 1992 BMW 325iC | 1968 Cadillac Deville

            Need some help figuring out the ETM?

            Comment


              #7
              Looking at it it was K6, not K7. Sorry. The failure was caused when I turned on the blower fan. The car shut off and it blew the top off of the relay. When I opened it up there was melting of the wires from fuse 19 & 20. The wire from terminal 20 had to be clipped about 4 inches back before I could find good copper.

              I will check the ICV tomorrow when I go out to work on the car. Is there anything else I should be checking if the ICV makes or doesn't make noise? I'm going to be bringing a 12v test light and some other miscellaneous tools.

              That's awesome! I'll have to open it back up and make that change. I had been wondering how to get all the lights to stay on with the high beams. I won't encounter any overloading of the circuit doing that will I? I don't want to have any more electrical problems. I'm over reading wiring diagrams at this point.
              - Josh
              1990 325is

              Need a shift boot?
              Looking to buy shift boot frames, PM if you have one to sell

              Here's what happens when you let the internet pick your license plate

              Comment


                #8
                K6 is for the aux fan, and goes to one fuse. K7 is the one your car cooked and it does two fuses. (incl. the blower motor)

                Now, the million dollar question is how the heck your blower motor managed that! Was it the OE 30A fuse? OE relay? That's nuts!

                The fact the car shut off is interesting too, since there really isn't much that runs through the fusebox that has anything to do with the engine, except the fuel pump (Fuse 11)

                The engine's electronics are powered via the separate fusible link in the trunk, which could have blown as well. BTW, out of curiosity, you didn't replace the main relay did you? It's special...

                Anyway, on to the ICV. If it's buzzing, odds are the DME and the associated engine electronics are working, and the no-start might be tied into the fuel pump due to the fusebox trauma. Check fuse 11 for power when cranking.

                If there is no buzz, pop out the main relay, and check terminal 30 of the relay's socket for power. If there is power, unplug C101 and check terminal 7 of the fusebox side of the plug for power with the key in the run position.


                As far as the headlights, Take a look at the circuit board pic you posted. You will note that the inner terminal of every relay except K3 and K4 are in fact connected to that bolt. The inner terminals are terminal 30, and they usually are connected to a power source. K4 receives it's power source through K3, the highbeam relay, so that when K3 becomes energized, power gets diverted away from K4, turning the low beams off.

                By moving the wire, you are completing the supply circuit to K4 directly, instead of through K3 so the low beams are no longer dependent on the highbeams being off to complete the circuit. No overloading, runs through the factory fuses, factory switches, and everything just works as it should. Makes soldering wires to relays really seem like hackery, doesn't it?
                -Dave
                2003 Lincoln Towncar | 1992 BMW 325iC | 1968 Cadillac Deville

                Need some help figuring out the ETM?

                Comment


                  #9
                  Gotcha. Then K7 for sure. I couldn't believe it popped a hole in the relay cover. The million dollar answer is that an owner or two ago someone put a 70A auto-reset breaker in there to (i'm guessing here) fix a repeat blow for the fuse on the blower motor. The resistor is toast so it's only got vortex-speed. By the looks of the carnage there was some serious current being drawn, as well as some pretty ridiculous heat generated. I'm amazed that the car didn't start on fire at some point before I got it. The wire for spot 20 was hard and the insulation cooked for about 5" from the terminal end.

                  I will check fuse 11. I was going to check the fuel pump relay too.

                  Where is this fuseable link? The car cranks and everything seems to work just fine. It will crank all day long too. I'm guessing the main relay isn't in the fusebox? Can you tell me where the main relay and C101 are located?

                  That's pretty slick on the headlights. Looks like a class-A modification in my book. And soldering wires to relays IS hackery, no question about it. I will for sure make that change next time I'm looking for something to work on. I wish I'd known that before I put it all back together.
                  - Josh
                  1990 325is

                  Need a shift boot?
                  Looking to buy shift boot frames, PM if you have one to sell

                  Here's what happens when you let the internet pick your license plate

                  Comment


                    #10
                    Ah, well now you know what 70A through a 30A relay looks like! Sweet!

                    Inductive loads (like motors) screw more people (and cars!) up than any other wiring problem sans ground issues. I guess even to the point the breaker seemed like a good idea to somebody?

                    Anyway, the fuel pump, oxygen sensor and main relay are located under a small plastic cover by your coolant reservoir and power steering reservoir. The white one is the main relay, and the orange one with mostly red wires is the fuel pump relay, the orange one with mostly green wires is the heater relay.

                    The main relay receives power from the fusible link (in the trunk along the main battery cable) and is triggered through the DME when it receives power through pin 7 of C101 (located on the firewall, next to the fusebox. Round connector)

                    The main relay supplies power back to the DME, and to stuff like the ICV, fuel injectors, etc. and the fuel pump relay.

                    The fuel pump relay is controlled by the DME, and is commanded on when it sees the engine is spinning. This supplies power to Fuse 11, which in turn goes to the fuel pumps. That's really the only thing I can think of off the top of my head that would shut the car off and cause a no-start dealing with the fuse box itself. However, lots of things including all of the wiring for C101 run through the fuse box as well.


                    Glad you like the headlight mod, I try to keep my stuff as factory correct as possible, if it's not factory original. :up:
                    -Dave
                    2003 Lincoln Towncar | 1992 BMW 325iC | 1968 Cadillac Deville

                    Need some help figuring out the ETM?

                    Comment


                      #11
                      Originally posted by DaveSmed View Post
                      Ah, well now you know what 70A through a 30A relay looks like! Sweet!
                      Kinda shitty to see it though. Makes me a little sad I didn't walk away when I saw the big breaker before purchasing the car. I'm glad the rest of the car is in good shape though.

                      Originally posted by DaveSmed View Post
                      Anyway, the fuel pump, oxygen sensor and main relay are located under a small plastic cover by your coolant reservoir and power steering reservoir. The white one is the main relay, and the orange one with mostly red wires is the fuel pump relay, the orange one with mostly green wires is the heater relay.
                      Awesome, thanks. I wish I had snapped an underhood pic now. All I remember seeing over by the coolant reservoir is the airbag sensor.

                      Originally posted by DaveSmed View Post
                      The main relay receives power from the fusible link (in the trunk along the main battery cable) and is triggered through the DME when it receives power through pin 7 of C101 (located on the firewall, next to the fusebox. Round connector)
                      Is the link identified in any way? I've never worked with fuseable links before so I'm not sure what to look for. Wouldn't this being bad prevent power from reaching the front of the car though?

                      Originally posted by DaveSmed View Post
                      The main relay supplies power back to the DME, and to stuff like the ICV, fuel injectors, etc. and the fuel pump relay.

                      The fuel pump relay is controlled by the DME, and is commanded on when it sees the engine is spinning. This supplies power to Fuse 11, which in turn goes to the fuel pumps. That's really the only thing I can think of off the top of my head that would shut the car off and cause a no-start dealing with the fuse box itself. However, lots of things including all of the wiring for C101 run through the fuse box as well.
                      Great, thanks. Sounds like checking fuse 11 is the easiest way to see if something's bad elsewhere. I should be able to test everything with a 12v test light I think.


                      Originally posted by DaveSmed View Post
                      Glad you like the headlight mod, I try to keep my stuff as factory correct as possible, if it's not factory original. :up:
                      For sure. I despise hackery. What other cool stuff you got? I saw someone had done speed sensing wipers and that seemed pretty cool but I don't really like the extra module you have to hang off the fusebox the way they did it.

                      And totally unrelated... is there something I can check to figure out why my power mirrors are non-functional?
                      - Josh
                      1990 325is

                      Need a shift boot?
                      Looking to buy shift boot frames, PM if you have one to sell

                      Here's what happens when you let the internet pick your license plate

                      Comment


                        #12
                        Tested everything tonight and it appears the fuel pump relay is bad. Test light shows power when cranking but fuse 11 neve energizes. The local BMW dealer had one in stock and my wife graciously volunteered to go pick it up. They said the new one is 5 pin though. We'll see when she gets back. Hopefully it does the trick.
                        - Josh
                        1990 325is

                        Need a shift boot?
                        Looking to buy shift boot frames, PM if you have one to sell

                        Here's what happens when you let the internet pick your license plate

                        Comment


                          #13
                          Changed the relay to no avail. Still no power at fuse 11. Which pin on the relay is the trigger? I have 2 pins that are hot with the key on but don't see another getting voltage when cranking. Where does the trigger voltage come from to energize the fuel pump relay?

                          Pin 7 of C101 is hot with the key on and the stomp test seems to work so I don't think the DME is bad.

                          Here's a pic of where I have power:
                          - Josh
                          1990 325is

                          Need a shift boot?
                          Looking to buy shift boot frames, PM if you have one to sell

                          Here's what happens when you let the internet pick your license plate

                          Comment


                            #14
                            Originally posted by Cletonius View Post
                            Changed the relay to no avail. Still no power at fuse 11. Which pin on the relay is the trigger? I have 2 pins that are hot with the key on but don't see another getting voltage when cranking. Where does the trigger voltage come from to energize the fuel pump relay?
                            The two pins getting power with the key on is good, that means that the main relay is working, and the DME is powering on.

                            The two pins are for feeding the fuel pumps themselves (pin 30 on the relay, pin 87 goes to the pumps and gets connected to 30 when the relay energizes) and for powering the relay coil itself (pin 86).

                            Pin 85 is grounded by the DME to control the fuel pumps.

                            The relays in an E30 are NOT a standard arrangement, if they just gave you a random 5 pin relay, odds are overwhelming that it will not work right.

                            Give this a try, see if fuse 11 powers up:

                            -Dave
                            2003 Lincoln Towncar | 1992 BMW 325iC | 1968 Cadillac Deville

                            Need some help figuring out the ETM?

                            Comment


                              #15
                              Cool, thanks Dave. The relay they sold me is p/n: 61-36-8-373-700. It looks very similar on the diagram, just that there's an extra pin in the center that's activated with the other one. I can post a pic if you're interested.
                              - Josh
                              1990 325is

                              Need a shift boot?
                              Looking to buy shift boot frames, PM if you have one to sell

                              Here's what happens when you let the internet pick your license plate

                              Comment

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