62RDSTR

Completed a simple enough fuel gauge replacement, when I went to start the car, the pink wire on fuel gauge smoked up pretty good. There is a little damage on pink wire to thermostat but the main issue is on fuel gauge wire.

Quite a buy of smoke filtered out through steering hub so I imagine some issue up on turn signal as well.

Outside of replacing dash harness (8 years old), what is the best way to fix? I don't see where anything was wired incorrectly so I'm not sure what the issue is so I don't repeat it.

thanks
jim

AZDoug

Oh, No! Not the dreaded fried pink wire!

There are some plastic (or fiber) bushings the keep the gauge terminals from contacting the gauge housing. They are accessed from inside the gauge, IIRC. I also think there is fiber shim on the backside to keep the terminals from touching the case, been several years since I looked.

I would look for one of those bushing to be cracked/broken, missing, or possibly you managed to make a dead short to ground on the hot side of the gauge some other way during installation.

I did this once on the temp gauge in 1984.

Doug

62RDSTR

I don't see any other wire damage but plan on pulling harness tape back to see how far it may have gone.

Doug, I have the original gauge out and don't see those bushings you were referring to. I'll pull the new one out and double check that one.

buns

The gauge is fused, so a dead short should have blown it. I would check the amp rating of the fuse, perhaps it is higher than it should be.

AZDoug

"Something" has to keep the hot gauge terminals from contacting the grounded gauge housing where the terminals go thru the holes.

Look and you will see what i mean. If you cant find an electrical insulator there, that is your problem.

Doug

62RDSTR

I did a continuity check between the two gauge posts and there was no continuity between them.

Based on that I don't believe there is an issue there. I'll take a part and check everything out though.

buns

You should be checking for continuity between the pink wire terminal and ground.

AZDoug

That is also a very good point. Too often people take a box of 20A fuses and install them in all slots.

Doug

62RDSTR

Thanks for the feedback.

I did verify that the fuses matched correctly. 2.5, 10, 7.5a going by memory bottom upwards. They were also intact.

I took apart the pod and snapped a couple of pictures.

One picture is of the pod with temp gauge on left and fuel gauge on right. Neither have the plastic or rubber insulator piece between the holes and stud.

I also took a pic of the original gauge next to the new one.

if I understand, on the pod itself there should be some plastic or rubber insulator piece in the little holes to prevent the studs from contacting the metal pod.

I assume this should be only on the driver side stud (pink) to prevent the dead ground. Also assume this should be on both gauges.

The temp doesn't have one either but maybe just lucky that the stud never touched the pod.

I hope I got that right. Thanks again for your help.

jim

Frankie the Fink

Here is what the back of the 61/62 'small' gauges should look like...
You have a Bubba-ed up mess with what you show in the pics.

62RDSTR

I don't doubt that...

I do have the felt paper or whatever the black square material that stretches across both terminals (it is shown on the left of the picture; everything is disassembled). I also have the paper that folds into the large ridge between the posts (not shown). I don't see too much difference between what I have and what you are showing. There was an orange/red tag that fell apart when i took the pod apart.

Outside of that, it matches what you are showing; at least externally. Do you have anything showing those insulators?

AZDoug

I do NOT have pic of the insulator. All i have is memory of a piece of half round opaque plastic appearing piece falling in my face after I heard a light "snap" when tightening a wire on my temp gauge, in 1984, and I got the smoke, so i disconnected the hot wire, and i replaced the gauge pod a year or two later.

Obviously "something" must isolate the terminals from the case.

If I was doing that, or if you were here, i would spin up a little donut out of Delrin in my lathe and shove it in the holes.

You may be able to find some plastic washers at Ace hardware in those bins they have in the nut a nd bolt section, that would work.

Doug

Frankie the Fink

Yes, I think you could find some nylon bushings to isolate the terminals from the gauge cases and prob get by with that....

You really, REALLY need to add a 30 amp ATC blade fuse to the black wire at the ammeter...this will protect 95% of your cars circuitry from dead shorts. These cars are lightly fused and many have burnt down to the valve stems from electrical fires.

Search for a post by me titled "C1 fuse points" for more info...

AZDoug

Looking the back of the original gauge removed from its pod, i believe I see an outline on one of the terminals (lower) of the bushing that is supposed to be there. These would be flanged bushings, with the flange on the inside of the housing, and the part that goes through the hole, probably about the exact length of the thickness of the sheetmetal. The fiber strip would provide the insulation between the capture nuts and the case on the back.

I have had people tell me" there are no bushings". Well, "something" must be used to isolate the terminals from the case, I doubt the original manufacturer would rely on careful assembly techniques to keep the terminals from shorting to the case..

And in reality, most cars people have or have worked on, have been worked on so many times in the past, stuff is simply missing or not put back correctly, they lose the pieces of they disintegrate, so the gauge gets put back together carefully sans bushings, so the terminal doesn't touch the case and they call it good, and the next person that takes it apart says these gauges don't have bushings.

Having had my car for 45 years, i have a pretty good idea of what was original, in many cases, but I have also been fooled. Maybe they just used those small punches in the gauge housing to to align with the slots on the side of the gauge board to keep things aligned.

Doug

ack fia

there should be a flat insulator tab that is formed to go around the post on the back of the gauge. If not there, I have used a small "O" ring on the posts to insulate them from the metal pod. A variety of "O" r`ings is available from Harbor Freight.

AZDoug

Good idea on the o-rings, readily available and you don't need a lathe.

Doug

GTOguy

I would cut a piece of vacuum hose and slide it over the stud and then cut to length with a razor. Fast and bulletproof for another 40 years or so.. and it would stay put.

62RDSTR

I appreciate everyone's comments. I'll fix and let you know of any further issues!