Hello all, this my first post but I been using this forum for several years to help my 85 580 SE along. I had some little "heathens":Banghead pull the wires out of the relays that are under the instrument cluster. Could someone help me with the color of the wires and which number on the relay they go to? This model only has 2 relays and it's the one that uses the AC Delco alternator. Thanks!
Can you tell me the wire colors with numbers that are involved. (Wire numbers or "K" relay numbers?) I see 3 relays vs. 2. Does your have a beacon light? If so does it work? Also can you advise if the engine will not start, or any of the lights not work. (brakes, flasher or working lights)
Ok...It looks like 1 relay had the following wires/colors 1- Big Red Wire, 1 White with a black stripe, 1 White, and 1 White 2nd relay has 1 big red wire, 1 Blue with white stripe, 2 Black with white or grey stripe, and 2 red/orange wires. There is no beacon light. No lights or flashers have ever worked since we bought it 5 years ago. It is truly a farm hoe! It does not start because of the disconnected relays. I did manage to trace the wires that had 2 red/orange down to the fuel shut off on the fuel pump. The larger red wires carry 12 volts continuously. I believe the larger red wires that carry the 12 volts should go on the 30A terminal of the relay. Other than that I'm lost and don't want to mess/fry anything up! Thanks for you help!
I will try to help sort this out one at a time. I think this relay above is "K3" or the Starter Solenoid Relay. Wire #14 is red and comes from the main circuit breaker. (Always 12V) This is one side of the K3 relay contact. --- Wire # 57 is white/black and is the other side of the K3 relay contact. This goes to the connector for the engine harness and then onto the actual starter solenoid. ---- ---- Wire # 3 is white and comes from the start terminal of the ignition switch. It is hot (12V) when the key is held over to the start position. This white wire goes to the "+" side of the K3 relay coil. ---- Wire # 4 is also white and goes down to the neutral switch. This should be shorted to ground if you have it in neutral. This wire connects to the "-" side of the K3 relay coil If you are unsure which terminals are the coil (2 white wires) check resistance across the terminals. The coil will read some resistance. 40 ohms is a wild guess. (no wires connected to do this) This is where the white wires go and I hope the + and - are identified. I am looking at a drawing and not the actual parts so it's hard for me to not be of more help here. If you get the 2 white wires connected you should be able to turn the key to the start position and see if the relay energizes. (other 2 wires still off) Then find the two terminals that close when the relay is energized. The relay contact will not be polarity sensitive. It just closes the circuit between the red and white/black wires. (SO, if you was to touch the red wire to the white/black wire... the starter solenoid would energize.) Hopefully this will get the unit back to cranking.
Good. This would be related to K1 relay so hopefully this will not be involved, although I wonder if some of your wires will be unused because of this. See more in next post.
I HOPE this is K2 or the relay for all the lights, but the colors do not match properly. Wire # 13 is red and will always be 12V. This actually connects to the same point as the other red wire from the starter relay. This red wire connects to the relay contact on K2 just as the K3 relay did. --- The other side of this K2 relay contact shows to be a dark blue/white wire # 24. This goes to a 15A breaker, possibly shown as R4. And another Orange/white wire (#25) is connected to this wire and feeds another 15A breaker R1. Also the drawing shows a "BAT" terminal which is POSSIBLE related to the alternator, but I am unsure about this. The above is the power wiring to enable all the lights to work. These wire carry more current than the coil wires so they are possibly larger wires. ---- Now the colors get vague... --- Wire # 10 is orange and comes from the ignition switch being hot when the switch is turned to "on". (12V) This is the "+" side of the K2 relay coil. This wire may be spliced (or blade connected) to another orange wire # 6 that MAY go to the instrument cluster. This part of the circuit goes all over the place including R2 which is a 10A circuit breaker. ---- Wire # 18 is black and goes to the "-" side of the K2 relay coil. This should be a ground wire possibly connected at the relay bracket. I suspect here that you will have 2 black wires that will connect to the same point. ---- As you can see the colors are different. You say the black wires have a white or gray stripe.? If your lights do not work at all this relay could be bad. When you turn the ign switch on, that Dark blue/white wire should have 12V on it. The relay should click on and off with the switch being turned on & off. If so then then you can work on the actual light switches. This part is really confusing because the fuel shutoff solenoid (you called it a "pump?) has nothing to do with these relays. I see a Light green/white wire that comes from R3 (10A breaker) that goes to this solenoid. This turns to a red wire at some point. SO for this I suggest you do this FIRST before working on the relays at all. Turn the key on and find that solenoid underneath the injector pump. This is a single wire and with the key on, 12V. Key off, 0V. This needs to be working before you try to crank it. No voltage it will not start. If you have 12V that you cannot turn off, the engine would run without the key on. Generally like colors connect together, but not 100%. The wire should have some memory so you may be able to tell where they "probably" go- just from the length and stiffness. Get a good white led flashlight and look for places where the connectors were plugged on. Hopefully this will help. If you are still unsure I will look some more at these cheesy drawings I have. I have read that Cat puts actual numbers on wires and Case does not. ? (Case does do show numbers on the drawing.)
Have you already looked at the parts page? I am guessing your does not have the test switch. View attachment 580SE_WO_Test-Switch.pdf
WOW! Thanks so much for your knowledge. I have looked at the parts page and is does not have the test switch. I even have the service manual but it is so old I couldn't read the wiring diagram it has faded just enough for my old eyes not to make it out. I gonna go out and try to get it work. Thanks
bowen, Thank you very much for all your information. I am happy to report the old gal is back to running....until something blows or breaks. Such is life.