1979 x1/9 (US), headlight/marker/"parking" light operation - what's "correct"?

Fiataccompli

Fiataccompli

Chris Granju
As I'm about to add various circuit improvements (relays, BWM, uncovering the dash backlight switch & hazard switch previously buried behind a custom center console by the PO, reviving some switch backlighting, etc.) on my 1979 X1/9, I've found myself slightly baffled by the light switch operation. A quick search seems to indicate the '79 operates differently than the '81 I once owned & the '85 I currently own. As best as I can tell (still cleaning up various components & connects as this car has been mostly under water at some point...so I put the electrical fun off to last for some reason), the switch operates as follows:

head with key on, headlights & marker lights...all function as intended
park with key on, no lights
park with key off, marker lights

I would have expected with the switch in the center position & key on, I'd have marker lights, pods up, but no headlights....though I gather that is very un-European (drive with headlights, mark your parked car on the side of the village road with parking lights, right?). I have the '80-'81 wiring diagram book (presumably, leftover from the '81 I owned) and while most of it is relevant to my '79, the diagrams I have show a blue/stripe wire coming from the switch & on my '79 I have a solid blue...and, there is no sign of wiring harness hacking.

Are there '79 wiring diagrams floating around on the 'net? I can add key-on marker lights to the car without too much grief (in fact, before I realized how it was working, I liked the fact that 'park' didn't engage the pods lifting!) if I want to....mostly I want to start at a known 'stock' circuits point before adding relays.

thanks in advance for indulging yet another stupid question on my part!
 
Fiataccompli said:
as this car has been mostly under water at some point...so I put the electrical fun off to last for some reason
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Very understandable.

Although my '79 wasn't under water, it has significant wiring issues (mostly rotted wires and connections plus some prior owner stuff) that I'm just beginning to sort. So at the moment I don't know what the headlight switch does on it. Sorry I can't offer input but I'll watch to see what I can learn along with you.
 
Thanks...I guess...maybe...I'd swap brief inundation of all wiring & electrical components (thankfully, crankcase & transmission were promptly flushed) for hacks & burns.... My '79 now starts & major systems all function...lights more-or-less with one headlight motor not moving & some bulbs out...but that is stuff that all appears to stem from the outer edges (literally & figuratively) of the project, so I'm not worried about them. I thought the heater fan was DOA, but it turns out it just needed to be flicked & now it's fine...pulled the dash because I'm dying it black, so it's the ideal time to check/clean wiring & add the typical improvements which the PO had on a to-do list before the car fell on tough times.
 
Likewise, I want to dye my dash black plus add all of the usual wiring upgrades (in addition to fixing problems). I also want to rebuild the heater/ac box with some modern upgrades to the AC stuff. So I'll be pulling the dash as well. Others seemed to find it a very difficult job, how did it go for you?

Have you considered the dash illumination change to LED's. This was discussed heavily a few years ago (when I was previously active on the forum). Not sure of the latest view on it though.
 
Sounds like we are on similar adventures at the moment. No AC on this car and since the fan has all appearances of being okay, I'll call it that for now.

Today I picked up an LED bulb to light the fiber optics. It would seem the same type (nicely diffused it appears) could work nicely for the instrument cluster if I wanted that. Somewhere in the old threads on instruments & maybe LEDs, you might come across some photos of the one in my 85 that was chopped up and rearranged by a PO...the end effect works fine, the back looks like a crazy spaghetti mess of soldered jumpers but he also inserted custom placed LEDs (which makes sense after rearranging) that have a gothic spotlight effect that I would describe as terrible but functional.
 
You are quite correct! 79 headlight switch (with ign on) turned to the parking light position, does not raise the pods, while the 81 does. I compared the wiring diagrams and it made sense to me. I didn't like it on my 81, when the pods would come up in park lights position, so when we started working on our 79, I checked out the wiring diagrams to figure out how to make it so they would only come up in the headlights on position, with the ign on. When looking at the 79 diagram, it appeared that it should work that way. Went to check it on the car and it did! The parking lights should come on, I believe, in the parking light position, with the ign on OR off. We have both wiring diagrams and should be able to scan them in and email to you.
We also have changed the instrument cluster bulbs to LEDs and a bench test of the cluster looked good to me. We also selected an LED for the fiber optic light source. It looks better in the holder but we haven't tested it as a system yet. I think we may have had to shave that LED to fit in the holder better. Putting an LED in the heater switch housing is proving to be a bit more of a challenge, but I think still doable. When using the T05 LED bulbs in the cluster, I have found that I like the results better using a bulb of the same color as the idiot light lens. The bright white tends to wash out the color. Also, when using the T05 LEDs that have a "bullet" shaped end, touching the LED tip to a belt sander to flatten the end helps diffuse the bright light, with the result of a nicer "glow" on the driver's side of the instrument cluster. In using these LEDs, you have to take the time to get the polarity right before you reinstall the cluster to make sure that they all work. Otherwise, you end up taking it out again.....that's why the bench test.
Hope this sheds some light on your project.
 
I purchased some LED's to add to the instrument cluster of another (non-Fiat) project vehicle. Pretty sure they are the "T05" size (been awhile). I recall finding them in a couple configurations of lens; bullet nose, flat nose, and concave nose. These are supposed to offer differing degrees of "glow" or dispursion, but I have not tried them yet to see.
Another thing I recall reading on this forum awhile back, some years of X's have a type of "brightness" adjustment control (for the instrument cluster lights) that works to adjust LED's brightness, but others have a different type that does not work with LED's. Bob Brown was the guru on this.

What size LED fits the fiber optic...same T05?

Would it be possible to post the '79 wire diagrams in the Xweb Wiki please? Like Chris said, the ones for newer models are available but none for the '79. I could really use it too (I have some unidentified wires to ID). Thank you.
 
I will try to get them scanned today and posted here. I have no clue how to post in the Xweb Wiki.
We are fortunate enough to know a local guy who used to work for a Fiat dealer back in the day. He gave us an actual Fiat wiring diagram book that he still had. It has been invaluable.
LEDs......You are right about the different types with the different light dispersion patterns. I didn't think that the ones with the concave tips worked as well in the instrument cluster application, but it has been a few years since I was fooling with them. In the end, we ended up trying a bunch of different types of bulbs. You will likely want to experiment with different bulbs to get the effect that you want. The fiber optic bulb is a T10, and I was mistaken last night...we did not have to shave that bulb. It IS of the bullet nosed type as I think that you want "all" of the light to come out of the end of the bulb to send it through the fiber optic line.
 
Here are the 1979 wiring diagrams for the headlights, parking lights, & interior lights.
Also, I haven't tried the dimmer on the LEDs yet. That may be interesting. However, my eyes need all the light they can get (that's why our garage has 36T8s lighting it), so we may just bypass it.
PS-the 79-82 electrical diagnostic manual, available at MWB has also been a big help.
I use it along with the diagrams here.
 

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Thank you for sharing the diagrams and other information.

On the LED's, I imagine you might have flattened the tips of the T05 bullet-end bulbs for the instrument cluster ones (vs the T10 for the fiber optic)?

Thanks Chris for allowing me to share in your discussion on this.
 
You are more than welcome for the info & Diagrams!
Yes, only the T5 instrument bulbs. Before flattening the tips, the light coming through the idiot light lenses was glaring and not as even across the lens. The sanded tip made the light more diffused (less focused) IMO. I haven't yet hooked up the fiber optic harness & switches with the T10 LED. Now I am curious as to how good it works. Maybe over the weekend. The instrument lighting also uses T10 LEDs. We tried several different types to get the brightness we wanted with the room available on the bulb holder. The cluster has a transparent greenish tinted "bubble" that the bulb has to fit into & a lot of the brighter T10 LEDs are too long to fit when you snap the bulb socket into the back of the cluster.
A lot of this comes down to personal taste.
 
So all of the LED's are T10, none are T05? I have not torn into mine yet (and may not for awhile...too much else to do on it first). But I do recall when buying LED's they were available in various physical dimensions for the same holder type (i.e. T10).
In past experiences I found it works best if the LED color matches the gauge's tinted lens color.
How many pages total in the '79 wire diagram book you have? Wondering if it is practical to offer them all to us? But understand if not. Thanks again.
 
In the instrument cluster there are 4 ea. T10s for illuminating the instruments and 11 ea. T5s for the various idiot lights, including the low voltage light in the voltmeter. We are using the space to the right of the parking brake indicator to light up when the second radiator fan is on, (indicating a higher temp) for a total of 11 T5s. Yes, using an LED the color of the lens works best. I did however use white T5s for the high beam (blue) and the rear window defroster (amber) rather than buy a lot of 10 for 1 bulb of those colors, and they still look pretty good.
The 79 wiring book has a total of 9 pages, including a component index. If interested, I could start a thread & post all 9 pages for everyone or if someone out there can tell me how to put them in the Wiki, I could do that. I have NO problem sharing the info. Besides, it was given to us!
 
Many thanks here! This will give me good stuff to dive in/finish the job over this holiday weekend (I hope).

No problem, Dr J....I'm all about sharing.

I'll watch along about LEDs, but generally I'm not so concerned..I like the idea of an LED powering the fiber optics, which are one of those Fiat things I often find discarded by POs & for some reason always enjoy restoring to function...which is odd for this car because it's in general very close to being a very bare-bones & purpose built X1/9 with the center console switches having been replaced by large mechanical oil pressure & water temperature gauges and the original switches buried. I will add basic toggle switches to the panel for the dash lighting & hazard light (maybe a fan 'on' switch & aux lights in the future)...but it's not Turin-fresh by any means!
 
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Fiataccompli said:
but it's not Turin-fresh by any means
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When I got mine it had been sitting in a field for some 12-14 years. The usual mice nests, spiders, debris, etc. So it was more "turd fresh" rather than Turin-fresh.

7982X said:
I could start a thread & post all 9 pages for everyone or if someone out there can tell me how to put them in the Wiki, I could do that.
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If the wire diagram manual is 9 pages and we already have 2 of them, then please post the rest if you would. I also don't know how to Wiki but the mods or others will help...I know they are listening! :p Or just add them here and I'm sure they can be moved later. Thanks again.
 
Let's give this a try....
 

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Excellent, thank you very much. I will be downloading this later today because I've come across a few wires on my '79 that I can't ID and they don't match the other Fiat wire guides (for newer models). Let me know if I can help you in any way.
 
Dr.Jeff said:
Excellent, thank you very much. I will be downloading this later today because I've come across a few wires on my '79 that I can't ID and they don't match the other Fiat wire guides (for newer models). Let me know if I can help you in any way.
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You are more than welcome! We are happy to have helped. I saw your other thread about the black wire. It "rang a bell" with me, but I went out & checked our 79 and did not see the wire. I could swear that we had that wire as well and I was wondering at one time, the same as you are. That was several months & numerous projects ago. I may have removed it as we will be wiring it more like the 82 that our engine is from. I will put some thought to it.
 
Regarding the mystery black wire. It's been suggested it could have been the original power fed between the alternator and starter, but a second one was later added and the old one just left hanging. That could match what I'm seeing.
Is your '79 a factory AC car?

Ooops, sorry Chris I went off topic again. I also sent you a "PM" reply.
 
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