Lights, Camera, Action!

[SteinOnkel]

Hello,

as I reassemble the Fiat, there's a few things I wanted to address and fix. For example, I built new harnesses for the tail lights. All lights and turn signals are working except for:

1) None of the marker lights Are the front ones supposed to be on constantly when the lights are on and flash when the turn signal for that respective side is used? The fuses are good, but for some reason none of these are working at all.

2) The ds brake light. This has never worked since I owned the car. I don't want to replace the whole tail light as they are $$$, but I was wondering if it would be possible to replace just the socket. On the PS I can see that they are screwed in. On the DS they are unfortunately riveted. Has anybody ever done this? If yes can you share your experiences?

3) I lost the socket for the front DS marker light. Does anybody know what type they are?

Thanks guys

[18Fiatsandcounting]

Steiny, your car is a 1978, right? My memory is fuzzy, but I thought the front turn signals were in the bumper, and the front marker lights (parking lights) were both on the side and in the same bulb/socket as the turn signals in the bumper. And I thought the bulb in the bumper assembly was the kind with two filaments: a high wattage one (18 watts?) for the turn signals, and a lower wattage filament (5 watts?) for the parking light?

Taking each of your questions in turn:
1) I thought the marker lights stayed on (same brightness) regardless of whether the turn signals are flashing or not. The side marker lights do not flash; only the front and rear lights flash.

2) Since one side is riveted and one side is screwed, it sounds like the DPO has been in there to fix the PS, but perhaps not the DS. Or mucked it up. First thing I would check is the bulb of course. There is only a single wire (red I think) from the stop light switch on the brake pedal back to the stop lights, so if one side is working and the other isn't, it's almost certainly a wiring issue in the rear, bad socket, bad ground, etc. Second thing I would check is that you are getting 12 volts to the DS rear tail light when you step on the brake. If not, you'll have to trace back as to where the break is. And yes, it is possibly to "rebuild" the tail light assemblies. I've had to do it on pretty much every early model spider that I've had. Disassemble, clean up, and put back together, most of the time with a new way to hold the socket in place (small machine screws). Unfortunately, the Fiat sockets are terrible in terms of corrosion, but you can buy a standard bulb socket at pretty much any auto parts store, but then the challenge is to figure out how to mount it in the light assembly. JB Weld!

3) It should be the same as the passenger side, and possibly even the rear side marker lights. Again, I forget exactly what you have in a '78, but I would imagine it's a standard socket for the smaller size bayonet bulb.

Sorry to not be of more help... One last thing: It's always a problem with an electrical ground.

-Bryan

[RRoller123]

The front side marker lights (as factory wired) DO NOT blink with the turn signals, which are embedded deeply into the front bumper and can't be seen from the side. An obvious safety issue when sitting at a "T" intersection.

Daniel Stern Lighting sells a little device, which I have installed, which works fantastically, to make the side marker lights blink in unison with the bumper turn signals. I would do it on any Spider I owned, well worth the time and small expense and effort to enhance safety and functionality.

It is a small tube shaped device, which I attached to the side of the charcoal cannister with some long ty-wraps, and wired from there. Seemed to be the best mounting location.

[SteinOnkel]

All fixed! Thanks for the help guys.

Marker lights were getting a stellar 10(ish) volts*. I happened to have a whole kit of LED bulbs that fit so I used those. Even had a socket as well that fit great.

Drilling out the rivets on the tail light was easy peasy. Friggen dpo gooped everything full of dielectric grease so there was almost no contact. Cleaned everything, screwed it back together and huzzah! Let there be light!

*I wonder if it's the ground pods in the engine bay. I've cleaned them and put new connectors on every wire that goes to them, but still, it ain't great. I wonder if I should just replace the ground pods and sand off the paint underneath them.

@Roller that seems a pretty easily replicated circuit. And a massive safety issue, I agree. I'll wire something up.

[RRoller123]

On his website, Daniel Stern offers a wiring solution (free of course) that doesn't use his device, but the lights blink in opposition to each other, which I find bothersome, so I sprung for the device. That was about 8 years ago, works fine.

[spider2081]

*I wonder if it's the ground pods in the engine bay.

I like to install a new hefty star washer between the ground pod and fender well. I think its 1/4" id that fits well.

[18Fiatsandcounting]

Marker lights were getting a stellar 10(ish) volts

It's often a ground as you surmise and others have noted, but it could also be poor connections on the 12V wiring pathway to the front and rear. Fairly common.

If you measure only 10V between the hot lead at a side marker light and a good solid ground like the body, then it's the hot lead that's the problem. If you are measuring 10V between the hot lead and the ground lead of the socket, it could be either that's the problem. Or, you somehow bought a 10V battery for your car by mistake....

But, it sounds like you fixed pretty much everything so perhaps now is the time to "leave well enough alone."

-Bryan

[SteinOnkel]

Marker lights were getting a stellar 10(ish) volts

It's often a ground as you surmise and others have noted, but it could also be poor connections on the 12V wiring pathway to the front and rear. Fairly common.

If you measure only 10V between the hot lead at a side marker light and a good solid ground like the body, then it's the hot lead that's the problem. If you are measuring 10V between the hot lead and the ground lead of the socket, it could be either that's the problem. Or, you somehow bought a 10V battery for your car by mistake....

But, it sounds like you fixed pretty much everything so perhaps now is the time to "leave well enough alone."

-Bryan

There are two hitches in the system. Right side turn signals are sloooow. And the dash indicator sometimes lights up, sometimes doesn't. BUT perfect is the enemy of great, so I think we will leave it at that for now.

Figured out my hood latch today, buttoned up the tail lights (mmmh oh yeah fresh white painted car and freshly painted jet black trim looks KILLER). Gonna repaint some interior trim tomorrow and then the top and trunk lid will go back on. As soon as I can coax my better half to lend a hand She's always knee deep in some sort of programming fiasco or another...weirdo!

Is there a template somewhere for a trunk carpet? I'd like to make something neat myself.

[18Fiatsandcounting]

Right side turn signals are sloooow. And the dash indicator sometimes lights up, sometimes doesn't.
Is there a template somewhere for a trunk carpet? I'd like to make something neat myself.

Without getting into the politics of right vs. left, a slow blinking turn signal is indicative of a poor electrical connection somewhere. Could be a ground, could be +12V, but somewhere the two bulbs (front and rear) aren't getting the full 12 volts. That being the case, the current is less, and it's that current that determines the flash rate of the turn signal flasher. Might also simply be an old flasher (very common) or one of the bulbs is fading.

The dash indicator, well, that's usually a turn signal flasher that is, shall we say, passed its prime.

As for a trunk carpet template, I'm not aware of any, but I went and got myself a 4' x 5' indoor/outdoor floor mat from Home Depot or the like, did some rough measurements to get it roughly correct, and then just trimmed here and there until it fit just right. Looks good, and costs about $11. Plus labor.

-Bryan

[SteinOnkel]

Yeah it's faster with the engine running that's for sure. Maybe just leave well enough alone.

The mat is a good idea. I would have the added step of cutting up a 3/4" plywood. The original cardboard they put in the trunk was really rotted out. In any case, gotta hide that rusty rusty tank. No way no how do I want to deal with it and its 10 million hoses

[18Fiatsandcounting]

The "boards" in my trunk were pretty crusty as well, so I just got some 1/4" hardboard or the like at Home Depot and made new ones, using the old boards as a template. The "carpet" was something like this although maybe it was 4' x 5':
https://www.homedepot.com/p/TrafficMast ... /202259648

I did it on both my cars, and while not stock, it looks a heck of a lot better than the old crumbling rubber mat with the missing (or rusty) snaps. $20 or so for each car and a few hours labor. Be careful with trimming the mat, as it's easy to get a measurement wrong and end up with something goofy looking. I used a new Exacto blade for long straight cuts, pressing against a piece of cardboard or the like.

-Bryan

[aj81spider]

I did the same as Bryan, but used 1/4 inch plywood instead of hardboard. I also built wings that closed in both fenders and hid the gas lines on one side and the jack on the other. Unlike Bryan I didn't get the carpet at Home Depot - I got it at Lowes. I didn't have useable boards to start, so created paper templates for both the plywood and the carpet.

I think 3/4 inch might be too thick - and it will certainly be heavier and harder to handle when pulling out the center section to get the spare tire out.

I also built a battery box out of plywood with a cutout for my battery disconnect switch and covered that with the carpet too. It definitely isn't stock, but it looks pretty good.

[RRoller123]

Ground Pods!