Bad Battery or Bad Battery Disconnect?

[Clark K.]

My '65 Sting Ray is dead. Well, the engine will not turn over. When I open the door, the dome light does not illuminate. It could be that the old battery finally died. But, in checking the battery disconnect knob, it felt different somehow when I loosened it and then retightened it.

Has anyone had any problem with these knob-style battery disconnect switches? Here is a photo of the type I have:

[John M.]

Re: Bad Battery or Bad Battery Disconnect?

My '65 Sting Ray is dead. Well, the engine will not turn over. When I open the door, the dome light does not illuminate. It could be that the old battery finally died. But, in checking the battery disconnect knob, it felt different somehow when I loosened it and then re-tightened it.

Has anyone had any problem with these knob-style battery disconnect switches? Here is a photo of the type I have:

I had a problem with the knob style - the standard arcing had burned through the brass plating and exposed the pot metal.



My symptoms on my 1985 were a failure to consistently shift into overdrive, followed by a sudden stall at a stoplight about five minutes later. I managed to get it going again and made it home - I have since switched to the knife-edged type.

[Joe R.]

Re: Bad Battery or Bad Battery Disconnect?

Clark,

What is your battery voltage? Did you try connecting directly to the battery (losing the disconnect switch in the process)?

Joe

[Kenneth B.]

Re: Bad Battery or Bad Battery Disconnect?

My '65 Sting Ray is dead. Well, the engine will not turn over. When I open the door, the dome light does not illuminate. It could be that the old battery finally died. But, in checking the battery disconnect knob, it felt different somehow when I loosened it and then retightened it.

Has anyone had any problem with these knob-style battery disconnect switches? Here is a photo of the type I have:

I took all of them off my Corvettes. Now I just loosen the termenal cable. no problem. Theu should have made better than plated pot metal.
KEN

[Ed D.]

Re: Bad Battery or Bad Battery Disconnect?

The green knob disconnects only seem to last about two years! I replaced mine yesterday... same problem I buy them two at a time.

[Joel T.]

Re: Bad Battery or Bad Battery Disconnect?

Clark,

What is your battery voltage? Did you try connecting directly to the battery (losing the disconnect switch in the process)?

Joe

Dittos on what is the battery voltage and if low, have you tried charging it?

Joel

[Jack H.]

Re: Bad Battery or Bad Battery Disconnect?

The same mfgr makes a knife switch alternative for a few $$$ more. It's switch contacts are brass and SOLID.

The potential reliability issues with the Green Knob version of the switch have LONG been discussed and commented on in prior posts (see archives). Personally, I've known 2-3 club members who almost 'bought the ranch' when this switch failed while they were on the road, at speed, and electrical arcing raised the switch contact resistance to the point the engine 'died' on them...

[John M.]

Re: Bad Battery or Bad Battery Disconnect?

The same mfgr makes a knife switch alternative for a few $$$ more. It's switch contacts are brass and SOLID.

The potential reliability issues with the Green Knob version of the switch have LONG been discussed and commented on in prior posts (see archives). Personally, I've known 2-3 club members who almost 'bought the ranch' when this switch failed while they were on the road, at speed, and electrical arcing raised the switch contact resistance to the point the engine 'died' on them...

Thinking a little out of the box here - why don't we just require the knife blade switch? That way, newbies wouldn't have to learn the same hard won lesson over and over again...

[Jack H.]

Re: Bad Battery or Bad Battery Disconnect?

Three reasons:

(1) If used 'properly' the green knob switch works! What's it take to use it properly? Well, there's no tactile feedback to indicate when the switch is closed, so some get in a hurry, screw the knob until there's a spark of life in the electrical system and let it go there.

What causes the arcing, is looseness. IF the knob is screwed down GORILLA TIGHT, the contact surfaces will not move relative to each other, create arcing, and contact deterioration. So, if one is properly 'schooled' in the use of the switch, it works OK...

(2) I've seen one club member 'modify' the green knob switch to make it bullet proof. He went to a hardware store and bought a BRASS washer large enough to make contact and overlap the knob. Then, he silver soldered the brass washer to the switch contact bar giving it a SOLID, anti-arcing, construction profile.

(3) NCRS doesn't dictate how you do this/that function. That a creativity killer approach.

[John M.]

Re: Bad Battery or Bad Battery Disconnect?

Three reasons:

(1) If used 'properly' the green knob switch works! What's it take to use it properly? Well, there's no tactile feedback to indicate when the switch is closed, so some get in a hurry, screw the knob until there's a spark of life in the electrical system and let it go there.

What causes the arcing, is looseness. IF the knob is screwed down GORILLA TIGHT, the contact surfaces will not move relative to each other, create arcing, and contact deterioration. So, if one is properly 'schooled' in the use of the switch, it works OK...

(2) I've seen one club member 'modify' the green knob switch to make it bullet proof. He went to a hardware store and bought a BRASS washer large enough to make contact and overlap the knob. Then, he silver soldered the brass washer to the switch contact bar giving it a SOLID, anti-arcing, construction profile.

(3) NCRS doesn't dictate how you do this/that function. That a creativity killer approach.

Jack,

Good points, though I'll say that you should have been there on that late August afternoon when my beautifully prepared, going for it's 97% 1985 decided to keel over (and you might not have wanted to explain this to my wife).

It sounds like there might be an opportunity out there for someone to make a properly over-engineered knob switch. Until that happens, I'll be telling our newbies (I'm teaching a Flight Judging for First Timers class next week) to buy the knife blade switches.

[John H.]

Re: Bad Battery or Bad Battery Disconnect?

DITTO, DITTO, DITTO. As a newbie of about 6 years, I started with the
crappy knob, now use the blade switch past three years. Love it.

[Roger O.]

Re: Bad Battery or Bad Battery Disconnect?

The only problem I've seen with them is the 2 halves separate due to the heavy battery cable which allows them to reconnect,the person then loosens the knob a little more,and then a little more. When the knob is turned back in the 2 pieces are not parallel any more and the threads get crossed,then the connection is poor from there on out until failure.
Putting 2 plastic zip ties around the 2 pieces fixes the problem. 1/8 of a turn is all that is needed to disconnect so the threads never get crossed.
I had one guy that didn't like the zip ties so I drilled 2 holes through and used plastic bolts and nuts.
I posted some pics of the ties installed awhile back.

[Jim T.]

Re: Bad Battery or Bad Battery Disconnect?

I took all of them off my Corvettes. Now I just loosen the termenal cable. no problem. Theu should have made better than plated pot metal.
KEN

Ken with my 68 and 70 I disconnect the NEG cable at the frame location. 5/8 ratchet wrench, it takes less than an minute to disconnect and reconnect. Lot easier than moving the seat back and going into the battery box to do the same thing. My 85 and 96 I just use a 5/16 ratchet wrench on the battery NEG cable, have to raise the hood so it takes a few more seconds.

[John H.]

Re: Bad Battery or Bad Battery Disconnect?

GUYS, just buy the blade switch and get over it.
The knob switch is a pain in the &*#@.