Hot Rods Battery disconnect problems

Has anyone ever had issues with battery disconnect switches going bad?

We built a 1935 Ford Roadster with a 1953 Desoto 276 hemi from the ground up and have had 2 new switches go bad. If they had been cheap ones from harbor freight, I could maybe understand them going bad, but these were from Speedway.

Our buddy has been building cars for 35 years and has never had one go bad, so I'm thinking something else is wrong that is resulting in trashing the kill switch.

Any suggestions would be appreciated.

 

Ooops. 1925 Ford roadster, not 35. Shouls have checked before I posted

 

I've heard of others having kill switch contacts failing.
From Speedway, where was it manufactured?

There is worthwhile info here:
https://www.galvinpower.org/best-battery-disconnect-switches/

Review #2 sounds like a good one.

 

post some pics of switch, etc

 

By their nature, they have to be a fairly heavy-duty switch.
Make sure everything is shut off when the switch is thrown so there are no power draws to arc across the contacts.
Bust open the "bad" switch(s) to see if the contacts are burnt/pitted or if the switch has mechanically failed.

 

I have no idea where it was manufactured. Don't have the original packaging and can't find anything on the switch.
Here's the item in the catalog. We have the 2 post one

 

I’ve been using a high dollar Napa brand. Has worked for 6 yrs.

 

I wouldn't put a whole lot of faith in the part if it was a Speedway brand part. Speedway shows a page and them some of various battery disconnect switches battery disconnect switch | Speedway Motors, The Racing and Rodding Specialists
Most are rated for 150/175 continuous amps and up to 1000 peak during cranking.

Starting that engine shouldn't put a big load on the switch or the rest of the electricall system. Unless it takes a lot of cranking to start it all too often. It may take just buying a higher quallity switch.

 

FWIW, I’ve had 3 of these fail, 2 on on OT motor with a reduced size starter. They make contact on the outside edge of the base of the knob, and they burn. Never actuated under load. 2 other cars, no problem. I carry a wrench in the console of that car now so I can remove it when needed to get home.

 

Hmmm. Sometimes the sound system isn't turned off when we shut her down. Never gave that a thought about affecting the kill switch. We had just talked about tearing it open and looking inside. Thanks for the info

 

buy a Pollak switch pretty much “ the standard” on heavy equipment and industrial applications .

heve some that are 10 years old on skid steers and wheel loaders that are working just fine .


Biggest thing is the contacts being solid copper and the contact tips being quality as well .

lots of “ copper clad “ crap out there with small under spec tips the will crap out way to soon .

 

Even better than that Pollak switch is the genuine Caterpillar master switch that is very HD. Never seen one fail, and used on some very stout 24V systems- and has a key. All the others like the Pollak are copied from that design- at least on the outside

 

I paid $20 for a cole-hersee switch at o'reillys. I am assuming its a good brand cuz we always had a cole-hersee shutoff on our firetrucks. I am a retired firefighter.

 

Beside what’s all ready been said. That style switch comes in different amp ratings. So buy accordingly.

 

Had 2 from Speedway that were junk.bought a Cole hersey

 

We ran Cole-Hersee on our firetrucks with very little problems. We ran the cheaper ones on our race cars with a lot of trouble and finally used two of them to solve the problem. Our failures were due to water getting into the switch while we were washing the dirt from from the race car.




Bones

 

Speedway for electrical or suspension or engine parts or...Not me.
Marine cutoff switches like that Pollak unit above or Cole Herse. 4 poles so you can cut the alternator.

I bought an OT beach buggy and the cheap disconnect switch was the first thing to go. PO couldn't figure it out.

 

Our school bus fleet at work has Cole-Heres and Pollak switches, 170 buses, I don't think I've changed one out because it quit working in 20+ years. Handles feel off or the ends got corroded, but never cause they quit working.

 

Would those switches be best on the ground cable?

 

Funny you should ask. I put my quick release twist lock cable ends on the negative cable. Maybe if we ask which way current flows, we find out it matters? Or...which terminal gets the most corrosion the positive or the negative? I'm just think out loud, if I had a switch to place in line...would it matter then?

I don't know. Final answer.

 

I would put it there.
If you put it on the positive (in negative ground systems) you'll have a positive lead from the battery to the switch permanently live, along with the entire body of the car permanently grounded, in a crash the switch connection or other positive pieces of the circuit could get moved so it contacts the grounded body around it - and those are live even if the switch is turned off.
With the switch on the ground side the body is not live anymore. Just the ground wire between the battery and switch, and on the positive side only the wire from battery positive to the ignition switch and starter solenoid (assuming ignition is turned off), and the rest of the positive side is protected by fuses even if it is left turned on.

In short, putting the switch on the ground side will disconnect more of the car.

 

This is the real deal, that all the lighter-duty and maybe Chinese copies are made to look like. This is the one used on up to a D8 or D9 dozer, controlling dual 8D (huge) batteries on 24V systems. You want bulletproof, this is it- and it has a key for security
https://parts.cat.com/en/petersontractor/7N-0718

 

Those disconnect switches ARE junk. I only needed to use two of them to find out, i will never use them again

 

Cat or Pollack or Cole-Hersey. Nothing offshore. Another thing is make sure the connections are tight. We had a nice Cole-Hersey (which is now Littelfuse) one die on a piece of equipment at work because the cable was not tight on 1 stud, it got hot, and melted the composite in the back enough that the stud was loose and it got hot and....etc. Then it didn't work anymore. The M284 is marine grade with copper contacts. All the ones I have ever seen were USA made, but I have not bought one personally since Littelfuse bought them.

M-284 Series - Manual Battery Disconnect Switches from Switches - Littelfuse

 

pprather that is a great link you posted, thanks. My son is a "big wheel" at CAT here in Bloomington Mn so you can guess which ones I use. Every once in a while I have to remind him what dogs do to big wheels.

 

These are crap potmetal. Used to be brass (long time ago ) Mine broke in half driving to the State Patrol for inspection. Tried to find brass, maybe marine

 

Mine failed a month ago. Bought from Speedway. Have 4000 miles on the RPU over 5 years when it failed. Thought it might be the battery as the car had sat for a month. Just connected the outlet cable to the input lug from the battery thus bypassing it. Will replace it over the winter.