Gentlemen

I'm trying to get a general idea of what the various circuits control.

It appears that 30 and 30U have power at all times. So whats the difference between 30 and 30U

15 appears to be power key on from ignition switch.

87L Looks like it may be regulated voltage through the OVP relay. Has the base module replaced the OVP function?

61e I have no idea what this does.

Your help is greatly appreciated

Thank You
John Roncallo

Are those markings on a relay?

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Not on a relay. The are what the wiring diagrams are called Circuite 30 ect.

John Roncallo

The letters probably have a specific meaning to an individula circuit. 15 is switched ignition. On the 129 chassis drawing I looked at there are 15, 15x, 15r, and 15z connections. They get turned on at various stages of the ignition switch cycle. 30 will be hot all the time. 87 is the output of a relay and 61 is the exciter circuit for the alternator.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

30 would be hot all the time, unfused...30U would be fused.

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A Dalton

Thank You Arthur

That makes some sense I can trace the wires out to double check. The 30U terminal is larger I would think that would be the unfused.

John Roncallo

Thanks for the reply Steve. I'm still not sure about the 61e it doesn't seam to have anything to do with the alternator. It appears to be on modules for exterior lamp failure, ESP, ADS, RB.

Thank You
John Roncallo

61e should be charge/alt lamp indicator circuit.
30 should still be battey direct, so I think 30u would be battery return line [from alt]

So, they both are in the changing circuit.

__________________
A Dalton

Try doing a web search for DIN 72552 !

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Thanks MB DOC. Makes a lot of sense.

John Roncallo