131mirafiori forum

I'm have a weird electrical problem with my '75 131.  The ignition switch is very weak and I have wired relays in series, between the switch to headlights, also from the switch to accessories.  Since intalling the extra headlight relay the lights work great.  The second relay improved the voltage going to the accessories but, now I have a strange quirk.  If I switch just the park lights on it kills the car, everything goes dead.  Turn them off, or put headlight switch fully on everything works fine.  The only wiring diagram I have is one from an Autobook manual.  Unfortunately it is tiny and VERY hard to read.  Anybody have any ideas to what circuit, or what I might have done wrong.  Also, was curious if any one knows what the relay behind the rear window defogger switch is for, it is missing and appears to have suffered a meltdown at some point.  Thanx for any help 

the relay that your first series has behind the switch is to feed the defogger, that absorbs so much current that the switch cannot hold it. If I understand what you say, I presume that a previous owner took off the relay pretending the switch to hold the whole current, and so burnt the switch. About the rest, I have had a worn out ignition switch on my 131, that after 20 years of use ended up with lots of issues, for example I could not switch off the engine, or I could not switch on the lights, so I just suggest you to try a new or used but working ignition switch. Mine after changing was dismantled and I could see that it was extremely worn and loose.