Battery cut off switch

[Arch 93]

Does anyone know of a shop that repairs battery cut off switches? In this case, one for a 55 100-4. I checked with Nisonger, but as most of you probably know, they only repair gauges. I'd rather not buy a new one because I want to keep the car as original as possible.
Thanks

 

[tahoe healey]

Its very simple to open and clean and gently bend the spring to get better contact. I did mine two years ago and its been fine and I use it all the time.

 

[Dave Russell]

Good luck,

Check this reference;
https://www.team.net/html_arc/healeys/200405/msg00172.html

I don't know of any commercial shop that would touch it.

You can get the switch apart. Removing the C clip on the bottom releases the handle. Removing the grommets around the mounting holes lets the rest of it come apart. The fixed & movable contacts may or may not be reusable. The really weak part of the design is the small spiral wound compression spring that keeps the contacts & detents in contact. This spring anneals from contact heating & becomes springless. If you can find a good replacement spring you "may" have success. Make very good notes about how the insides are indexed when you take it apart. I guess it is worth a try. I think that some things are better not left original if reliability is important.
D

 

[Dave Russell]

[ QUOTE ]
Its very simple to open and clean and gently bend the spring to get better contact. I did mine two years ago and its been fine and I use it all the time.

[/ QUOTE ]
I think you were lucky. Springs don't lose their spring unless they are damaged. I'll bet that you are still not getting full designed contact pressure. But if it works, what can I say? I may be wrong.
D

 

[Arch 93]

Thanks to both you and Dave for responding to my question. Not being mechanically inclined, I have a history of taking things apart with the intention of fixing it, only to find that I can't even get it back togeather again, let alone fix it. Since I have two of these switches I'll try taking one apart and fix it. (Why not?). I suspect that eventually history will repeat itself and I'll end up buying a new switch. Thanks again for your help.

 

[elgatto]

Dave,
You might remember me telling you that I have owned my 1956 BN 2 for 23 years and from day one, I have had difficulty spinning the starter. I just read your response to "Battery Cut Off Switch," (the article that you referenced in your response) and I am wondering if the switch might be the culprit? That is about the only thing that I have not checked, other than taking it out and cleaning it up. I had the starter rebuilt, checked the cables, ubgraded the ground to the switch and grounded the engine to the frame with heavier cables and replaced many batteries. Now using one 12 volt Interstate which seems to have slightly improved the starting problem. It seems worse when the weather is hot and when I have driven the car a good distance. When I shut it off and try to start it after it sits for a time, the starter spins very slowly. I had the charging system checked over the years - no problems detected etc. Ideas??

 

[Dave Russell]

T,

I was able to resurrect the spiral compression spring by stretching it, heating & tempering in oil, & drawing it to a bluish color. If you can find metal grommets to fit the outer case holes, they will hold the case together. I found it quicker to turn hollow rivets out of brass, anneal them, & press in. The switch functions, but I don't trust it still, & am going switchless.

Have fun,
D

 

[bradal]

Thomas: You can always wire around the switch by connecting the battery terminal directly to a chassis ground. Then, whenever you have your switch repaired, place the switch back in the circuit. AL Bradley

 

[Keoke]

HI ELgatto, Do not know if your switch is good or bad . simple test: take it out of the circuit and see if there is any improvement.If not try this ,get some thermal insulation and wrap the starter in it and see if that cures the problem. However, I am not aware of a heat soak problem with the Healey cars.-FWIW---Keoke Additional things to try: If the eng-to- chassis gnd strap is not connected directly to the starter make that change.

 

[Keoke]

HI Dave, /ubbthreads/images/graemlins/yesnod.gif its really a snap to dismantle the cut off switch and refurbish it. However, if I was all thumbs I think I woukd just buy a new one and forget it ever failed. /ubbthreads/images/graemlins/tongue.gif

 

[Dave Russell]

[ QUOTE ]
Dave,
It seems worse when the weather is hot and when I have driven the car a good distance. When I shut it off and try to start it after it sits for a time, the starter spins very slowly. I had the charging system checked over the years - no problems detected etc. Ideas??

[/ QUOTE ]

As I said, "the switch" is frequently the cause of strange electrical problems.The simplest check would be to put the cable lug which is presently on the switch B (battery) terminal on the same terminal as the E (earth) cable lug. This will bypass the switch. Or if the battery earth cable is long enough, remove it from the switch & attach it directly to the frame.

You didn't ask, but the battery cables should be no less than 2 gage copper cable.

If this doesn't cure the problem there is a chance that the starter or solenoid has problems.

If you are profficient with voltmeters, you can measure the voltage from battery earth terminal to frame while cranking the engine. There should be no more than 2/10 th (0.2) volt reading. If it is higher, there is too much resistance in the switch or cable connections.

Similarly, attach a volt meter between the battery hot terminal & the starter main terminal. While cranking, there should be no more than .8 volts drop. If there is more, there is too much resistance in the battery main cable, it's connections, or the soleniod contacts.

Obviously you need a low range volt meter for this.
D

 

[Dave Russell]

[ QUOTE ]
HI Dave, /ubbthreads/images/graemlins/yesnod.gif its really a snap to dismantle the cut off switch and refurbish it. /ubbthreads/images/graemlins/tongue.gif

[/ QUOTE ]
Yeah - I know. Just plan on doing it every year or so.
D

 

[Keoke]

/ubbthreads/images/graemlins/nonono.gif Nah Did mine ten years ago no further problems---Keoke /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif

 

[Dave Russell]

-- OK --

 

[elgatto]

Keoke,

I will ground starter to chassis to see if slow spinning starter improves - good idea. Thanks
Mike

 

[elgatto]

Dave,
Thanks for the info. I will work with the volt meter and run some tests.

Mike