Low beams not working

[Zoofly]

Hoping for some help regarding the low beam headlights not working. I have H4 headlights installed by Allison's. My low beams quit working, but I don't know when since I rarely drive the car at night, but it's been around 6 months since I last drove at night when they worked. I do have hi beams.

I've checked all of the fuses which were fine. I checked the grounds inside the engine bay, and the ground pod underneath the steering column. I've jiggled the wires coming off the ignition (which is what I suspect is the problem) and I've also made sure the connector behind the headlight switch was fully locked.

Is there anything else I can check? I'm not very confident when working with electrical issues, so I see a ride out to Allison's if it gets too involved.

Thanks in advance for any ideas.

[SteinOnkel]

Does the kit also come with relays? Usually they do. The low beam relay could be stuck.

[18Fiatsandcounting]

Another possibility is that the electrical contacts for the low/high beam switch on the steering column stalk have gone flaky for the low beams. Fairly common, and the fix involves either a new steering wheel stalk assembly or fixing the existing one (hard, but it can be done).

You can test for this by measuring the voltages on the 4 fuses for the low/high beams (left and right), with the ignition on. If the two low beams fuses have no voltage, it's either a wiring issue or a stalk assembly issue as above.

I'd check all other options first before pulling out the steering column switch assembly, though.

-Bryan

[Zoofly]

I didn't have the relay installed when we switched to the H4s. Probably should have.

I get no voltage reading on the fuses for the low beams, but I get a reading on the high beams. So if I understand correctly, it may be a bad switch in the lever on the steering column, or possibly a wiring issue out of the ignition switch? Is that what you're saying?

[18Fiatsandcounting]

I get no voltage reading on the fuses for the low beams, but I get a reading on the high beams. So if I understand correctly, it may be a bad switch in the lever on the steering column, or possibly a wiring issue out of the ignition switch? Is that what you're saying?

Exactly, Zoofly. From what I recall, the "direction of current flow" for the headlights is power first goes to the headlight switch on the dash (on or off), then it goes to the high/low switch on the column, then it either goes to the low-beam pair of fuses or the high-beam pair of fuses depending on where the column switch is set. From there it goes either to the left/right high/low beams as appropriate. The headlights are always grounded.

The fact that you aren't seeing 12V on both fuses for the two low beam circuits would seem to indicate an issue with the column switch, or the connectors to it. If you remove the two plastic halves that cover the steering column, you can sometimes get in there with a voltmeter and see what's going on. Easier on the earlier model years than the later years.

Could be a connection issue, or (sigh), it could be the switch contacts in the column assembly.

-Bryan

[Zoofly]

Hi,
I want to close out this thread with the result. It was indeed the steering column switch that went bad on the connection for the low beams. I replaced the switch with a new one from Auto Ricambi and all is good. Some rainy day I may do an autopsy on the old switch and try and revive it. :0 Thanks for the help.

[18Fiatsandcounting]

Some rainy day I may do an autopsy on the old switch and try and revive it.

Thanks for the update, Zoofly, and yes, these column switches can be taken apart and the contacts cleaned/resurrected. It's not a super easy job, but if you're good with small intricate parts, it's not too bad. I've done several, both old style and the newer style, and after I've drilled out the rivets, I reassemble everything with 2-56 machine screws and nuts/washers.

-Bryan

[GreyDR]

Hi,
I want to close out this thread with the result. It was indeed the steering column switch that went bad on the connection for the low beams. I replaced the switch with a new one from Auto Ricambi and all is good. Some rainy day I may do an autopsy on the old switch and try and revive it. :0 Thanks for the help.

Great to hear you figured it out. My uncle is looking to get this '78 Spider as the next project after we finished installing the bumpers and dually wheels on the Superduty. The Spider owner mentioned the low beam is not working since the H4 installation. We'll check the fuses and the switch first.