will this wiring set up work?

[mollydog]

Thank you Richard for this

I'll be attempting this next week and post on here how I get on, many many thanks for this.

thank goodness there are laws now keeping people like me away from home electrics

 

[clydey]

yes diagram works perfectly
my only concern is the ecu switch
normally ecu use darlington transistors to switch loads (high/low)
the switch shows (open/closed)
my concern is the forced voltage on the darlington output (if indeed used) destroying the ecu
cheers

 

[mollydog]

Clydey, thank you for this bit of info, other that have wired it (like I had before) haven't heard any problems, but to be on the safe side would fitting a diode at location "C" solve/prevent the risk?

 

[clydey]

this is what i would recommend
introduce another bosch relay (same as original they come as 4 and 5 pins) choose 5 pin
call this relay 3
wire pin 86 of orignal relay to pin 86 of this relay
wire pin 85 of original relay to pin 85 of this relay
this then puts these two relays in parallel and when one energises so does the other
now open the output wire coming out of the ecu ( c) on your diagram (ie cut the wire so that you have two ends to work with)
put one end (any end) of the cut wire onto pin 30 relay 3
put the other end of the cut wire onto pin 87a of relay 3
---------------------------------------------------------
this results in a normal path when the relay is unenergised for the ecu output
and open circuits the output of the ecu when you
press your momentary button for the duration of time set by your timer relay
thus avoiding a conflict of voltages
cheers

 

[mollydog]

Thank you, Clydey for this, I think I have got it what you're saying, when I get home I'll do a diagram to show you to be sure I've got it right

many thanks for this further help

 

[mollydog]

had time to put it down to paper (computer) is this what you mean Clydey?




while I'm on a roll, for another car project, will this other diagram work too?


set up so the "Button" will not work unless the (car) lights are switched on but letting the RFID work at all times

remembering, I'm a weekend warrior when it comes to car elecrics

many thanks

 

[clydey]

at a quick glance no - the b wire goes to 87a not 87 on bottom relay cheers

 

[mollydog]

at a quick glance no - the b wire goes to 87a not 87 on bottom relay cheers

Clydey, many many thanks, like this?




(I have slight dyslexia, so don't see errors strait away)

 

[clydey]

yes just add fuses cheers

 

[clydey]

please keep in mind that this extra relay means that the ecu switch has no function and now that i look at the circuit with fresh eyes may even introduce chattering of the bosch relays engaging and disengaging when ucu switch operates.if no ill effects have been found in the other cars mods with relay 3 not fitted may be better to go that waythis is what happens in designing - a cure for something can introduce a further fault in the designcheers

 

[mollydog]

Thanks for this further info Clydey, the people I know of who have made this override to the fan as a strait cut in to the pin 86 on the factory fitted rely (as I have at this moment), have had no problems reported by them

in this case, would placing a L.E.D. at my "C" location prevent any issues with me (as I have at present) connecting the override switch at pin 86?

also (if you don't mind me asking) regarding my other project, would the way I have the diagram set up work?

many thanks

 

[Richard Burns]

The relay is switching the negative pole and so should not introduce a potential difference at the ECU.

The RFID scheme: the RFID, if it is switching relay 2, then when it close the relay it will operate the solenoid via relay 1 at any time.
If the lights are on relay 3 will be energised closing the contact to "button" and then pressing "button" (if it is a switch) will operate relay 1 and so operate the solenoid.
Personally I would try and keep to the same convention for the relay connections i.e. always use terminal 85 as positive and 86 as negative and not change them about in one circuit (or installation)

 

[mollydog]

Thank you for both your answers Richard

will use your first diagram for the fan overrode:With the RFID, plan to use it just as you described it, so just change pin 86 to - neg and pin 85 to + pos and should be OK to work, yes the "button" in my diagram is the switch, active only if the car lights are on



For future reference, good idea to keep 86 as neg and pin 85 as pos?


once more many thanks

 

[Richard Burns]

Thank you for both your answers Richard

With the RFID, plan to use it just as you described it, so just change pin 86 to - neg and pin 85 to + pos and should be OK to work, yes the "button" in my diagram is the switch, active only if the car lights are on


For future reference, good idea to keep 86 as neg and pin 85 as pos?

So long as you remain consistent with the terminals for + and - it is OK, it is when things get disconnected and you are not sure which is which that things can get confused, it will work either way, just nicer to be more ordered!

 

[clydey]

mollydog what concerns me the ecu switch when open is showing one end connected to -ve bat and the other end +12 volts bat through the relay contact (open circuit floating positive) ecu switch closes puts neg 12volts on B and relay pulls inperfectbut this is assuming the ecu switch as wirednow if instead of the ecu being a switch it is a what is known as a darlington pair transistorthis is common in ecu outputit is a switch also but with a differenceit has an input within the ecu that drives the base of the transistor with a small current between base /emitterthat causes a larger current to flow collector /emitter basically output is driven low from high (or opposite depending if transistor is pnp or npn) ok transistor theory boring.now substitute this into the diagram and see the differenceyou could basically be trying to pull an output to its opposite statei would disconnect the output of the ecu pinif it shows zero volts then it works as in diagramif it is 12volts then its not connected to bat -vecheers

 

[mollydog]

thank you Richard,I'v made a not of being consistent with the terminals

thanks


@ clydet

the biggest problem nowadays is that as Rover is no longer with us, its getting harder finding where to get information to ask questions, as the ECU, wiring loom and engine are all Rover parts.

as can be seen, I know little about relays and how they work but am an enthusiast and love doing these things, thinking out loud, would placing a LED between the ECU and the connection "B" would that stop and back feed to the ECU?

 

[clydey]

led = light emitting diode = nodiode maybegot some wiring diagrams via auto data for rovergive me as much info as possible about the engine year / size/ i will check my diagrams and see how the fan switching worksproviding i have the diagram cheersremember open circuit the ecu wire and measure to earth plus 12 volts or zero voltscheers

 

[clydey]

must have a virus using spacebar all okwill not let me edit post sorry with the words running into each othercheers

 

[mollydog]

if it will be of help, the engine is a Rover 1.8 K series 118 BHP (non VVC), model year 2000, with a MEMS 1.9

 

[clydey]

nearest ive got is a 2000 rover 25 /1.8 engine code k16 - 1.8 /mems 3engine coolant blower motor relay 1ecm -pin 67ecm switched earth outputengine idling - coolant blower motor off 11 to 14 voltsengine idling - coolant blower motor on 0 to 1 volt--------------------------------------------------------------engine coolant blower motor relay 2 acecm - pin 60 ecm switched earth outputengine idling - coolant blower motor off 11 to 14 voltsengine idling - coolant blower motor on low speed 11 to 14 voltsengine idling - coolant blower motor on high speed 0 to 1 volt-------------------------------------------------------------------------------engine coolant temperature sensor ectcomponent disconnectedterminals 1 and 2 0 deg = 5900 ohms20 deg = 2500 ohms40 deg = 1180 ohms60 deg = 600 ohms80 deg = 330 ohm---------------------------------------------------------------------------ecm pin 67 grey/blue and then to pin 86 relay 1 same colourecm pin 60 blue/yellow and then to pin 85 of relay 2 same colourdoes any of this match up cheers

 

[clydey]

sorry still got spacing problemtypes fine then bunches the wordsand when i edit i get a blank page to edit

 

[mollydog]

@clydey, thank you for going to all this hassle,

my car defenatly has the MEMS 1.9, the colour wire going in to pin 86 is the grey/blue as you mention. not looked on the ECU as its at the back of the car and hard to get to it to take off the connector to see, but the relays are at the front of the car and easy to look at and take out

I am sure mine, even though its a MEMS 1.9 would be like the description you mention, would placing and LED (light emitting diode) on the ECU side of the connection I'll be making (location "C") stop any problems occurring?

 

[mollydog]

Been busy this weekend doing a dummy run with the RFID before I fit it to the car, to be sure it works,

here's a couple of clips showing a dry run before I fit it to the car

RFID1 - YouTube

RFID2 - YouTube

One thing I was wondering, I have a Bosch S5 battery it's a 52 Am, do these RFID's use little AH to run? I've looked on the net to find out how to measure the AH of the RFID with my digital multimeter but with little luck

many thanks