Park Tail fuse melting box?

[msampsel]

It seems you dont buy that arcing is causing the fuse box melting

As I understand the fuse is not blowing but melting the fuse box
Which suggest there is not a overload on that circuit but a loose arcing connection
Have you started this car up in the night ? ,with no light ,you can see the arcing easily . Might have to tap the box slightly

If your you meant me, not so. Stacey replaced his fuse box with its loose
wire several pages ago. I thought loose connections were the cause of the melting box
and suspect it has been resolved yet there is lingering fear of heat
above ambient at the fuse.

However, checking in the dark fro arcing at the
box is another good test.

[svwilbur]

I dont think I have arcing. probably did at one time with the old fuse box.
I am just concerned about the warming and wondering how far it will go and how far it can go before it would want to melt wire or the fuse box?

to melt the box or wires does it have to get to 200 or more?

I have considered taking some bulbs out. but first I may see if it reaches peek and levels out at not too high a temp.

anyone know how high a temp would be safe or not safe for old wires?

basically I want any fires, melting or issues.

I was even thinking of a heat sync but that would be hot, temp and electrically so probably a bad idea.

better idea would be to locate issues and replace harnesses in the future. or at least wires on the park curcuit.

I may pull some bulbs to try to isolate a problem area. only saw one bulb and socket that had any corrosion when I cleaned them all.


one other thing, I thought the turn signals were powered through the flasher curcuit not the park,tail curcuit? and brakes thru a different curcuit too.

[svwilbur]

I have an idea. what if the bulbs being used are not the recommended wattage and are higher?

the park, rear tail, sidemarkers and license plate lights are suppose to be 8watt.
the backups are suppose to be 15 watt. if they have the wrong bulbs I may be using more amps than expected. time to see what they all actuall have in them.

[Curtis]

Park, tail and stop should be 1156 and 1157.

[svwilbur]

from what I read in the manual and what is in the car the front park and turn Is 1157, in park mode it s 8watts, in turn mode 23-25 watts (but that is on a different curcuit through the flashers I think)

side lights should be 12v8watt small glass top bulb, (much smaller than 1156 bulbs which are 27 watts)

rear park and stop and turn are (4) 1157 which are 8 watt in park mode and 23-25 watt in turn or brake mode

1156 should not be used anywhere they are single filament and 26.88 watts(2.1amps)

backup lights are suppose to be 12v15 watt,

license plate 8 watts

that is according to the 1970 manual.



So in park mode I would have 12 bulbs burning 8 watts each. 96 watts or about 8amps. less than half the rated fuse rate of 20amp. so you would not think that would heat up much.


that is (2) front parks (8watt) on the 1157 bulbs,
(4) rear parks (8watt) on 1157 bulbs
(4) sidemarkers, 8w
(2) license plate 8w

backup lights are seldom used but should be 15 watt each and not 1156 bulbs as there are two backups and that alone would be 54 watts 4.2 amps any time they are on.


I check most of my bulbs, most are correct.
one of the license plate lights is wrong and both backups are wrong as they had 1156 equivalents.

I need to check 2 more side markers which should be 8watt and 1 more front and two more rear bulbs that should be 1157 bulbs.

I am trying to reduce wattage in park mode. I could maybe change the 6 standalone 8watt bulbs to LED if I can find that small a LED "bulb". the 1157 could change to LED but then flashers have to be adjusted......so I don't want to mess with that.

[msampsel]

So in park mode I would have 12 bulbs burning 8 watts each. 96 watts or about 8amps. less than half the rated fuse rate of 20amp. so you would not think that would heat up much.

Fuses are not non-linear devices. Any current flow will increase their temperature.
A 20 amp fuse will not go from ambient temp to melt at exactly 20 amps.

Solder melts at 370 degrees (at sea level LOL) suspect the wire in the fuse needs to get close to this
to melt. So what is the definition of much?

[svwilbur]

I used my lights some done in Solvang each night and the lights held out and only got to about 120-140 at night for the 30 minute drive back to the hotel in Lompac. I don't know if it is fixed but it has worked for those times.

I have not had it out at night since then and now i have had the engine apart for a while.

[cktrap]

If your worried about the total amp draw for you lights. Why not switch to LED's and cut the amps by 50-70%. Less current = less amps = less heat

[svwilbur]

If your worried about the total amp draw for you lights. Why not switch to LED's and cut the amps by 50-70%. Less current = less amps = less heat

I have thought of that and checked some out locally. they are a bit pricey but I was more concerned about reliability of them after talking to the guy at the partts store. he said he used some and vibration seems to reek havoc on them. he had to replace a couple on his car. I guess I could swap some out and carry incandescent as spares.

the other issue was signal lights often ha e to have the flashers replaced to function properly on LED as the load is different.

do you have experience with them on a roadster? I love LEDs on and in my house.

[sunbeam590]

I had this same issue, did a report on here , after hrs of checking everything, and I mean everything it turned out to be my Dimmer switch, easy to check, just pull off the two wires and connect them together, bypassing the dimmer, I don't say this is your problem but worth a try, and now my dash lights are better as well..

[svwilbur]

I had this same issue, did a report on here , after hrs of checking everything, and I mean everything it turned out to be my Dimmer switch, easy to check, just pull off the two wires and connect them together, bypassing the dimmer, I don't say this is your problem but worth a try, and now my dash lights are better as well..

Thanks, I have not tried that yet. I guess I could also just play with dimming it and seeing if it changes the temperature at the fuse box.
I will try it once i get my current chain, sprocket, rockerm, cam , head project taken care of.

[yusef]

Is there any update to this?

I have a similar issue as my 20amp fuse has been blowing and using a test light connected between the hot side of the fuse holder and the other has test light bulb glowing.

[Curtis]

And the 69-70 fuse box rears its ugly head again.

[Curtis]

Here's my solution to the fuse box. A modern ATO 3 buss, 16 fuse box.

IMG_2167[1].JPG

[yusef]

I don't think mine is blowing due to the fuse box itself, as the fuse blows within a few seconds of installing. I suspect I have a short to ground somewhere.