Positive wire melting - The 1947 - Present Chevrolet & GMC Truck Message Board Network

amashal · 03-29-2015, 08:55 PM

I noticed the other day the small wire off the positive battery terminal to the junction block was warm to the touch. Went driving today and noticed it got hot enough to melt the connector. See pic. I'm not good with electrical so what are some things I need to check to fix this? Any help or suggestions are appreciated.

71meangreenc10 · 03-29-2015, 09:51 PM

Are you running a larger Amp Alternator or stock?

Smitty

amashal · 03-29-2015, 09:57 PM

Stock externally regulated alternator. It's a 71 blazer. I recently did the headlight relay upgrade with instructions off the site and everything with that seemed to go well. Lights are brighter than before.

71meangreenc10 · 03-29-2015, 10:18 PM

Well,
Since that is the case, I would see if it is the original wiring and maybe it's time for a new front harness. Corrosion can build up in the wiring and cause resistance and then you get hot wires. Also check to make sure you have good grounds.

I have cut some red wires apart and they were full of blue corrosion, not good.

Headlight upgrade shouldn't have done anything if it was wired properly, in my opinion.

Also check your voltage at the battery when running to ensure that the regulator is not over charging.

Smitty

_Ogre · 03-30-2015, 11:12 AM

i am not familiar with ''new'' truck wiring
that location would be where the fusible link would be
could that be a fusible link starting to go?

**michael bustamante** · 03-30-2015, 01:29 PM

what is that yellow plastic thing in the wiring thats melted? any chance it grounded out?
nows a good time to put a fuseable link on there

amashal · 03-30-2015, 01:37 PM

Should a fusible link be there? The yellow melted plastic thing is just a butt connector. I will check voltage this afternoon when I get home from work.

**michael bustamante** · 03-30-2015, 01:45 PM

the butt connector prob caused resistance and heated the wire up. you should use a fuseable link there if possable but i dont know what amperage. im sure someone here will let you know

cdowns · 03-30-2015, 01:50 PM

those cheepy Walmart connectors cause more problems than they fix/// look around for high quality connectors preferably ones that you solder to have the jobs done right

starterman99 · 03-30-2015, 03:51 PM

If it was hot and melted only at the connector that indicates high resistance at that connection. If the wire burned insulation all the way down to the junction it is a problem further down, but from the picture it looks like only the connector.

amashal · 03-30-2015, 04:34 PM

Yeah it was only melted at the connector. Wiring looked good where I soldered in a new fuse link. I warmed it up and drove around for 10-15 minutes and the wiring doesn't feel hot. I probably will look into rewiring soon just for peace of mind. Heres the readings I got after driving. 13.98 volts at battery and 14.7 at big wire on back of alternator. Do those numbers sound good? And thanks to everyone for the help.

**michael bustamante** · 03-31-2015, 11:28 AM

#s sound good good at the battery, glad you got it going again

03-29-2015, 08:55 PM	#1
amashal Registered User Join Date: Mar 2008 Location: Allen,TX Posts: 223	Positive wire melting I noticed the other day the small wire off the positive battery terminal to the junction block was warm to the touch. Went driving today and noticed it got hot enough to melt the connector. See pic. I'm not good with electrical so what are some things I need to check to fix this? Any help or suggestions are appreciated. Attached Images

03-29-2015, 09:51 PM	#2
71meangreenc10 Its a Truck Thing...... Join Date: Dec 2004 Location: Sierra Vista, Arizona Posts: 3,159	Re: Positive wire melting Are you running a larger Amp Alternator or stock? Smitty __________________ 71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 71 C20 Longhorn/Ole Yellor 69 C30 Former Motor Home, Flat Bed time

03-29-2015, 09:57 PM	#3
amashal Registered User Join Date: Mar 2008 Location: Allen,TX Posts: 223	Re: Positive wire melting Stock externally regulated alternator. It's a 71 blazer. I recently did the headlight relay upgrade with instructions off the site and everything with that seemed to go well. Lights are brighter than before.

03-29-2015, 10:18 PM	#4
71meangreenc10 Its a Truck Thing...... Join Date: Dec 2004 Location: Sierra Vista, Arizona Posts: 3,159	Re: Positive wire melting Well, Since that is the case, I would see if it is the original wiring and maybe it's time for a new front harness. Corrosion can build up in the wiring and cause resistance and then you get hot wires. Also check to make sure you have good grounds. I have cut some red wires apart and they were full of blue corrosion, not good. Headlight upgrade shouldn't have done anything if it was wired properly, in my opinion. Also check your voltage at the battery when running to ensure that the regulator is not over charging. Smitty __________________ 71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 71 C20 Longhorn/Ole Yellor 69 C30 Former Motor Home, Flat Bed time

03-30-2015, 11:12 AM	#5
_Ogre Registered User Join Date: Jan 2012 Location: Motown Posts: 7,677	Re: Positive wire melting i am not familiar with ''new'' truck wiring that location would be where the fusible link would be could that be a fusible link starting to go? __________________ cool, an ogre smiley Ogre's 58 Truk build how to put your truck year and build thread into your signature shop air compressor timer

03-30-2015, 01:29 PM	#6
michael bustamante Registered User Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,843	Re: Positive wire melting what is that yellow plastic thing in the wiring thats melted? any chance it grounded out? nows a good time to put a fuseable link on there __________________ 1967custom

03-30-2015, 01:37 PM	#7
amashal Registered User Join Date: Mar 2008 Location: Allen,TX Posts: 223	Re: Positive wire melting Should a fusible link be there? The yellow melted plastic thing is just a butt connector. I will check voltage this afternoon when I get home from work.

03-30-2015, 01:45 PM	#8
michael bustamante Registered User Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,843	Re: Positive wire melting the butt connector prob caused resistance and heated the wire up. you should use a fuseable link there if possable but i dont know what amperage. im sure someone here will let you know __________________ 1967custom

03-30-2015, 01:50 PM	#9
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Positive wire melting those cheepy Walmart connectors cause more problems than they fix/// look around for high quality connectors preferably ones that you solder to have the jobs done right __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

03-30-2015, 03:51 PM	#10
starterman99 Registered User Join Date: Jun 2008 Location: santa maria,ca. Posts: 312	Re: Positive wire melting If it was hot and melted only at the connector that indicates high resistance at that connection. If the wire burned insulation all the way down to the junction it is a problem further down, but from the picture it looks like only the connector. __________________ 1957 3100 1950 5 window

03-30-2015, 04:34 PM	#11
amashal Registered User Join Date: Mar 2008 Location: Allen,TX Posts: 223	Re: Positive wire melting Yeah it was only melted at the connector. Wiring looked good where I soldered in a new fuse link. I warmed it up and drove around for 10-15 minutes and the wiring doesn't feel hot. I probably will look into rewiring soon just for peace of mind. Heres the readings I got after driving. 13.98 volts at battery and 14.7 at big wire on back of alternator. Do those numbers sound good? And thanks to everyone for the help.

03-31-2015, 11:28 AM	#12
michael bustamante Registered User Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,843	Re: Positive wire melting #s sound good good at the battery, glad you got it going again __________________ 1967custom



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