Battery Cutout Switch

[Guest Fred2b]

As a security measure I want to fit a battery cutout switch to my 2B with EFI setup, but I think the computer unit loses it's settings everytime the power is disconnected and has to re-learn everything once the power is on again. Am I correct? And if so will it do any damage longterm?

Is it possible to keep the brain box connected but put the cutout on the starter only. Would this cause any problem if the ignition key is turned on?

Any help on this please.

Peter

[Guest mark kingston]

Yes they do a cut out switch with a low rated fuse bypass which when the knob is removed will still power things however if you turn the key before refitting the knob then the fuse will blow under the load and kill all power.

i brought mine at one of the shows but i think they do them in europe.

[Guest Battery Bill]

Fred

has to re-learn everything once the power is on again.

How does it do that then? and how long doth it taketh because we are fitting a cutout switch also.

How does it work when a battery change is required then, I know i have to reset the radio on the Mondeo but nothing else seems to have any problems.

[Guest ians2B]

Peter,

 

I am/was/maybe doing this as part of the security measures for SVA (long way off) dont you need two ways of imboilizing the car? how did you do it? and now thinking about it its probably not a good idea to keep turning the power off from the ECU often.

 

 

Ian

[Guest rizla]

bill a ecu learns by the signals that it gets from the engine ie position sensor (crank),temp sensor etc

 

if a battery is disconected it makes diddly sqwat to the ecu,as soon as you give it power it is then ready to get the signals it requires to perform as soon as you start cranking

[Guest sps137]

"if a battery is disconected it makes diddly sqwat to the ecu,as soon as you give it power it is then ready to get the signals it requires to perform as soon as you start cranking "

 

normally i'd agree but the haynes manual recommends idling for three minutes and the driving for a few miles before the system will run properly. Seems a bit advanced for an early system but is there a chance that it self modifies the maps to allow for wear and tear on the bores etc. i'd be intersted in knowing if anyone has any better suggestions. of course it could just be haynes usual innacuracies

 

simon

[Guest rizla]

that is true you do have to drive the car under various conditions for the ecu to get all the info,but believe me you wont notice any differance the ecu has default set values and will run perfectly well from start.

i used to do group A hot rod racing with a ecu,no alternater and removed battery every time i finished s race,never nissed a beat,DIDNT ALWAYS WIN THOUGH :angry:

[Guest brummy-ade]

that may be like curborough lol win that is!!!!!!!!

[Guest mark kingston]

like most of us you will already have two.

one being the ignition key and the other being the steering lock.

[Guest bloke]

i disconnected me batt in me car twice and its never run the same again - engine cuts out at idle from speed... just coincidence i suppose

 

oh an bill, where will you site the switch sorry!... ill get me coat

[Guest Battery Bill]

I'm wiff Rizla on this debate, And as for Haynes manuals "Garbage"

You can get more info from the "Topper" annual 1974 issue.

Bloke

i disconnected me batt in me car twice and its never run the same again

Did you remember to connect it up again then?

Oh and we will be fitting our switch in the passenger footwell, Its just the job as thats where all the big boy live wires meet up, its an ideal spot as there is plenty off room now that massive chunk of ballast has been relocated in a much more sensible space

[Guest rizla]

bloke this can only be a coincedence,and not a result of disconecting the battery

[Guest Mr Pid]

I to plan to connect a cut out switch, but i am planning to put it in the ignition circuit so as to leave power to the rest of the car, if needed, as i am planning to put other various computers into the engine to monitor its running.

 

(anyone know which wire is best to splice it into?)

 

When i had my engine tuning by mr mobile tuner bloke when he came round and we eventually got the beast running the diagnostic module had to run a series of test on the system so it could recalibrate itsele, it basicly mimicked idle, driving and high rev driving- pretty similar to what mr haynes recommends.

 

We tuned it after the ecu had "learned" what to do and the engine purred like a kitten, so there may be some truth in it after all.

 

The fact that the engine went bang 30 minutes later was nothing to do with this - but hey it did run very smooth!

 

Stu

[Guest ColinR]

I'm considering a cut out too. I saw three options at the Shepton Mallet show. One fits on the battery terminal with a low rate fuse. You remove a screw in knob to cut out. The fuse supplies the accessories, but will blow if anyone tries to start it. Disadvantage - you have to lift the bonnet (sorry, boot lid) to use it.

 

The second one was a big switch with a removable key. All feed is cut when the key is removed. The third looked like the second but with additional contacts, presumably for the low power accessory feed. Prices ranged from £4.50 to about a tenner, depending on the stall. I''ll probably go for the third option.

 

The diffuculty may be with an acceptable sva location as the key swithches are quite bulky and have to fit through a panel. The dash would be the logical place to put one, but would Mr SVA like it.

 

Don't know where you would fit one in the footwell Bill as it projects into the car by a good inch and half or so. If it's not required for the sva it's perhaps better to leave it like the winscreen etc.

 

Colin

[Guest Battery Bill]

Colin

Don't know where you would fit one in the footwell Bill as it projects into the car by a good inch and half or so. If it's not required for the sva it's perhaps better to leave it like the winscreen etc.

We will be fitting ours at the front end of the passangers footwell to get it you will have to reach down (Then upwards) if you know what I mean there will be a slot cut in the board covering all the electrics etc so when the key is inserted and turned it is our of sight and no SVA problem (Touch wood)

Bill