Technical lighting problems

[johny1976]

I have a 77 Fiat spider, when my lights are on, I only have one low beam, but both high beams when switched, they are dual filament bulbs, what can be causing thiis and how can it be fixed. Thanks

 

[GeorgeT]

Check the low beam wiring and connections. There are two filaments so one may have blown but the high beam filament okay. Now would be a good time to install a headlight relays to take the high amp current out of the ignition switch/headlight switch loop.

 

[Spider75]

I agree with GeorgeT,
The low beam is out in the one light this is more common that you would think.
A new bulb is a cheap and easy fix.

 

[Spider75]

GeorgeT,

How do install the relay that you are suggesting for the headlights and where can I get one?

 

[GeorgeT]

GeorgeT,

How do install the relay that you are suggesting for the headlights and where can I get one?

Search the Fiat Forums for "Headlight Relay Installation" for specifics, but it is as follows:

1. You will need two relays, one for high beams and one for low beams.

2. Mount the relays in the engine bay (I mounted mine on the inner fender, near the alternator).

3. Cut the low beam wire going to one headlight and attach it to the low amperage lug on one relay.

4. Attach the low beam wires going to the headlights to the high amperage lug.

5. There are several attachment points for 12v for the headlghts but I tapped off the aternator output terminal going to the battery.

6. Repeat for the high beams.

7. Be sure to ground the relays.

Once you do this, only the low current required to operate the relays will go through the ignition and light switches, extending their lives as well as having brighter lights.