850 Sport Coupe Relay Position?

Discussion in 'Rear-Engine Fiats' started by Jeff Stich, Sep 9, 2019.

  1. Jeff Stich

    Jeff Stich True Classic

    Location:
    Norco, CA
    850 Sport Coupe with alternator (1970-on in USA); with the alternator field relay mounted to the engine bay ceiling (to the right of the ignition coil), what is the position/orientation of the relay? With the wiring terminals (spades) pointing to the right (passenger) side, or to the left (driver) side?

    Also, can a Sipea T20-12 relay be replaced with a (more-common) T-5170? (they are near identical-looking except for the position of terminal 87). The T20-12 is rated at 20amps/12Volts, anyone know the Amp rating of the T-5170?
     
  2. dnudelman

    dnudelman Daily Driver

    Location:
    Glendale AZ
    The is an x 1/9 in the local pick n pull. Any value in snagging this relay off the x 1/9 for future? Or have we figured out a modern substitute that still is in production?
     
  3. Jeff Stich

    Jeff Stich True Classic

    Location:
    Norco, CA
    The only "value" would be for you to simply have it as a spare (they rarely die, but sometimes a rusty wire terminal will rip out if/when trying to pull a wire off). I have a few spare T-5170's already (& a few other #'s), but my early Euro car has a T20-12 on it, hence my question(s).

    More importantly, show/tell us: what is the position/orientation of this relay on your 850 Sport Coupe?
     
  4. kmead

    kmead Old enough to know better

    Location:
    Michigan
    I have both relays in the engine bay next to the coil. My car came with a generator and without adding wiring there was no way for me to get the alternator light to work. On both of my relays the wiring terminals face towards the firewall.

    I don’t know the answer to your other questions.

    Mine worked fine for two decades but I made the mistake of jumping my wife’s car and haven’t been able to get the system to work properly since. I am changing to an alternator from a Panda which is internally regulated. It is posing other problems but is low on my list of activities to solve right now.
     
  5. Jeff Stich

    Jeff Stich True Classic

    Location:
    Norco, CA
    After a bit of detective work on my car, I found that the original mounting position of the alternator field relay was with the wiring terminals facing towards the ignition coil (ie: to the left). Unfortunately, this won't work on my car due to the fact that I'm retro-fitting a Marelli Plex 201 EI ignition coil pack (same finned alloy housing/coil/etc. as used on 124 Spider 2000) in place of the original points-type coil & bracket. The finned alloy housing wants to sit right where the relay wiring is, & squishing the wires up against the side of the alloy housing would (eventually) not end well.

    I ended up rotating the alternator field relay 180° on its mount, so the terminals now face to the right, instead. Various wire routing methods were tried, until I finally found an acceptable routing solution where the Plex coil pack fits in place & no wires were pinched or stretched or rubbing on anything nearby. I still have a bit of repair work to do, as the engine bay wiring harness on this car is quite a mess (partial cuts/slices or burned/melted areas, loose or missing end terminals & some wires randomly cut short).

    Btw, I chose to stick with the Sipea T20-12 relay that was already on the car, even though one of the wire terminals is "iffy" (a little loose). At least until I find out if the T-5170 is a direct swap, or locate/buy a new T20-12. ;)
     

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