thanks Ken and Douglas,

Ken - it totally makes sense. I also think the problem happens now and not
before because of the aging of the connector and/or the wire itself.

Douglas -  good point, I have this crimper:
https://www.amazon.com/gp/product/B0069TRKJ0/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
but not at the time I wired the Jay Brown's relay kit, I used a cheap one,
aaargh... lesson learned.

On Wed, Sep 30, 2020 at 10:00 AM Kenneth O'Connor <kenneth.oconnor@gmail.com>
wrote:

> Current flows in a circle... from the positive node of the battery,
> through the positive wire, to the load, then through the ground wire to the
> negative node of the battery. If you use a proper sized wire for the
> positive side, but an undersized ground wire, then it can absolutely burn
> under load.
>
> Does this make sense?
>
> Thank You,
>
> Ken
>
> On Wed, Sep 30, 2020 at 9:48 AM Dan N <dn92610@gmail.com> wrote:
>
>> hi all,
>>
>> Could ground (-) wires melt/burn under heavy load?
>>
>> I never heard about it or have seen one till now. I've seen hot/positive
>> (+) melted wire but not ground (-) one.
>> My daughter drove her 1998 Carat (stock) with high beams ON and suddenly
>> smoke came out under the dash, engine died, she pulled over, shut the
>> engine, waited a bit and restarted the van and the same thing happened
>> again, got it towed to me.
>> The van has Jay Brown's headlight relay kit but uses 55/80W bulbs 6 years
>> ago and working fine till now. The fuses 20,21(low beam) are OK, the
>> casing
>> of the fuses 9,10(high beam) were melted but the fuses are not blown. In
>> the back of the fuses panel there is a gray #53 relay and the ground (-)
>> wire that goes to the ground tree was melted and touched the positive (+)
>> wire on the same relay.
>> I replaced the 4 fuses (20,21,9,10) with 15A fuses instead of 20A,
>> repaired
>> the positive (+) wire, replaced the ground (-) wire with 14 gauge instead
>> of 16 gauge and installed an inline 10A fuse on it. I ordered a new #53
>> relay (not here yet) just in case. All working well now.
>>
>> Sorry for the long description but I try to find out why this could
>> happen... quite scary and I wonder how to prevent this.
>>
>> Thank you for any ideas.
>>
>> dan
>>
>