8v to my signal light?

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ManzanoNissan
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I've got a 1991 D21 4x4 I'm restoring. Front right signal marker won't light up. I've replaced the entire assembly, replaced the turn signal/lights switch, checked the wires from the harness where it splits to the side marker and headlight, no frayed wires and both the side marker and headlights work fine.

I was given this diagram but honestly it's like reading Greek to me and It doesn't help me to source what to do?
https://forum-attachments.sfo2.digitalo ... f58f8e0ce9
299034_b4c46398a614a26522ba04f58f8e0ce9.jpg
I ran a multimeter on the connection to the assembly and I get just under 8v. I ran a multimeter on the bulb housing in the assembly and got a reading just over 2v. I placed pins in a couple locations of the hot lead wire after the wire harness splits and got the same just over 8v reading at both points where I pinned.

So should I be peeling the wire harness electrical taping off right up to where the harness goes into the back of the engine firewall into the cab?
I think I'll try removing the glove compartment and gaining access back there to see what I see as well.

Thanks for any advice.


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VStar650CL
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Since it's just the one lamp, first make sure your ground wire is good. Do that by connecting a test lamp to battery+ and then probing the BLK wire terminal at the turn signal. It should light up brightly, if it's dim or out then the ground wire is frayed or broken somewhere. If ground is good then the GRY/RED wire must be frayed or broken somewhere between the switch and the lamp, probably at one of the splices buried in the harness. To prove it, you can jump a long wire direct from GRY/RED at the switch to GRY/RED on the lamp. If there is a break in one of the wires, trying to unbury it on a harness that old will be nightmarish. You'll be better served to cut the offending wire at both ends and run a new one on the outside of the harness.

ManzanoNissan
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Ahhh thanks Vstar, that's both reasonable and logical. Appreciated. Would you consider running the replacement directly to the turn signal switch on the steering column?

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VStar650CL
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Yep, the WD doesn't show any intervening connections to worry about. Replace the whole wire end-to-end.

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VStar650CL
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Just to be clear, you want to T-tap it at the switch end because it does feed the other lamps. Cut it away and butt-splice at the lamp end.

ManzanoNissan
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Well as luck would have it, I repaired it and didn't know it.

When I pulled the original assembly a couple months ago I found the negative had a small bit of insulation missing a couple inches back from the connector. I had taped that but obviously I hadn't taped it properly? When I went back the other day to do pins and multimeter, checking, I removed any previous tape work I did and retaped all the area's I was working. Now the signal marker works.

What was the lesson in this case?

I didn't tape the negative specifically, for some reason I can't remember I ran tape around both wires and I know better.
I'll gather that the missing shielding when mated in close proximity to the hot wire (even though it is insulated) will cause impedence because there isn't enough insulating material to stop electric fields interplaying between both wires, causing a drain.

Or in short: not taping the missing section on the negative and just wrapping both wires was the cause.

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VStar650CL
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ManzanoNissan wrote:
Thu Jul 15, 2021 6:22 am
Or in short: not taping the missing section on the negative and just wrapping both wires was the cause.
That probably explains your 8V, a low grade short through old and porous insulation. Bad enough to deprive the lamp of juice but not to blow the fuse. Good job, glad you got it straightened away!

ManzanoNissan
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Nope turns out the problem has become intermitant in that it stopped working, I opened everything up, retaped every thing, it started working. Then stopped working but started working after driving through heavy rain, then stopped working today.

I'm thinking the connector is the problem but I can't source one.

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VStar650CL
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ManzanoNissan wrote:
Sat Jul 24, 2021 4:30 pm
I'm thinking the connector is the problem but I can't source one.
If you want to post a pic, we have a pretty extensive connector collection at the shop, including a lot of old stuff. I can't raid the boxes for free, but if you can't find the thing anyplace else, maybe I can match it up for you or get you replacement pins.

ManzanoNissan
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Hey VStar thanks. No freebie's expected. I'll post a pic here in the next couple day's. Raining hard here right now. I'll gladly pay cost and shipping!

ManzanoNissan
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Ok I got the pics of the connector and I'm posting them per your reply on connectors at the shop. Gladly pay the cost and shipping of course if you've got one to send. What is your shop and contact?

Image

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VStar650CL
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That looks familiar, I think I recall seeing one of those in the lighting-connector bin. Won't be at the shop till Tuesday, I'll let you know then.

ManzanoNissan
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Awesome. Thanks!

ManzanoNissan
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VStar650CL wrote:
Sun Aug 08, 2021 7:04 am
That looks familiar, I think I recall seeing one of those in the lighting-connector bin. Won't be at the shop till Tuesday, I'll let you know then.
Hey VStar did you have a chance to see if you had any connectors at the shop that look like this one?

https://imgur.com/ibZFJ6w
https://imgur.com/ByVg7D9
https://imgur.com/crSvFVA

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VStar650CL
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I didn't, no, sorry. If you didn't know about it, this is why. Life's been a little screwed up, but I should be at the shop tomorrow.

topic629559.html

ManzanoNissan
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Aw hey man, I'm really sorry. We just lost a kitty a month ago. She was a trooper and had cancer. Still hurts so I get it. No worries on the connector. Take your time. All the best to your family.

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VStar650CL
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ManzanoNissan wrote:
Sat Aug 14, 2021 6:50 am
Aw hey man, I'm really sorry. We just lost a kitty a month ago. She was a trooper and had cancer. Still hurts so I get it. No worries on the connector. Take your time. All the best to your family.
Thank you. There sure is big old hole in our household right now, like our hearts all have "vacancy" lit up in neon.

I would've swore we had at least one of those connectors in the boxes, but I can't find it. One of the other techs (who wasn't working today) is restoring a D21, so he may have got to it before I did. I'll ask him on Wednesday. If you want to mail me the connector, chances are we have replacement pin-pigtails in the factory kits and I can re-pin it for you. That's the best I can do, PM me if you want to try it.

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VStar650CL
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20210826_082438.jpg
20210826_082449.jpg
Well, I missed it the first time, I found you a matching pigtail. It was in the regular 2-pin box and not the lighting connectors. I checked pin-fit and conductivity, it's good. However, I also checked pin-fit and conductivity on your original, and it's good. So either there's a problem with your male connector pins or the resistance was in part of the wiring that you excised. I'll PM you about how you want to proceed.

ManzanoNissan
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Yep. I'm thinking I'll just run wire from where these (front marker, headlight, signal marker) split from the harness and see if circumnavigating that area I was test/reading is enough to get the job done. Seeing as I was getting results from probing just a few feet back of the connections, it's likely somewhere in there I've got corrosion built up perhaps from exposed insulation over years.
Thanks for checking this for me and helping to narrow down the issue!

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VStar650CL
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ManzanoNissan wrote:
Sat Aug 28, 2021 8:41 am
Yep. I'm thinking I'll just run wire from where these (front marker, headlight, signal marker) split from the harness and see if circumnavigating that area I was test/reading is enough to get the job done. Seeing as I was getting results from probing just a few feet back of the connections, it's likely somewhere in there I've got corrosion built up perhaps from exposed insulation over years.
Thanks for checking this for me and helping to narrow down the issue!
You're most welcome. I'll get the stuff on the way back to you. As I mentioned in the PM, if the problem is thinning of the male pins, you can try giving them about a 15 degree axial twist using a hemostat or a very fine needle-nose. That will usually restore good contact by increasing force on the springs in the receptacle. If that doesn't help, then yes, I'd say excising and replacing the wires in the suspect area is the way to go.

ManzanoNissan
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Yeah the signal markers are all brand new though so ... yeah ugh. Electrical. I will try giving them a wee turn and see if that helps at all first.

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VStar650CL
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ManzanoNissan wrote:
Sun Aug 29, 2021 9:26 am
Yeah the signal markers are all brand new though so ...
If they're aftermarket, it wouldn't be the first time I saw undersized pins. In fact, it's pretty much endemic with some types of aftermarket connectors like A/C compressor clutches. We had one Max that kept coming back for intermittent compressor dropouts after installing a China compressor, the original tech couldn't figure it out. When it made it to my bay, I found an 0.020" male pin instead of the nominal 0.025". One quick twist and no more issues, after the poor guy spent probably 4 hours fighting with it over the course of three visits.
;)

ManzanoNissan
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Yes they are aftermarket. Considering the intermittent on and off again everytime I was down there disconnecting and retaping ... the original marker on that side was burned out, along with broken tail lights, I just switched them all out to brand new stuff and with that marker side still not working, I would have never believed the problem to be connection points in the marker itself but I will definately give those pins a small 15 degree turn. And see what happens before going through the pain of rewiring. Thanks V!

ManzanoNissan
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You were right. I gave the contacts in the signal marker a slight twist, maybe less than 15 but the result was instant. Soldered, heat shrink tubing on both and then taping. I don't think I'll have anymore issue's there, finally. Thanks for the help Vstar!

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VStar650CL
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You're most welcome, glad you got it working!


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