Ignition Relay

[Guest bloke]

does the ignition relay feed power to ignition switched electrics like lights etc...?

 

throught the big fat wires and fuses?

[Longboarder]

The standard sierra ignition relay is rated at 70 amps IIRC. Black unit with two big 9mm blades and two 6.3mm switching blades. It cannot carry all ignition switched current to ignition coil, computer, fuel pump, injectors, wipers, heater blower, washer pump, indicators, stop and reverse lamps and on top of them the main/dip beam current. So the easiest solution is to hive off greedy stuff like main/dip to their own relay or pair of relays and just use the ignition relay or ignition switch to supply the relay switching current controlled by the column stalks (that has the benefit of not burning out the stalk switches). Side lights get a constant live supply so can be left on as park lights but when you switch off the ignition the main/dip go inactive. Clever innit.

Nigel

[Guest bloke]

cheers for the info longboarder,

 

have had another squiz at the gubbins and the ignition relay (70A) on my hains diag supplies heater blower, fogs, dimdip (whatever they are?), heated windows, wipe and washers. could i squeeze the lights on this?

 

the engine management relay (40) does all the engine bits

 

how would i hive off a supply for the lights? would it be by connecting another relay as the ignition (fat supply and feed with an earth and appropriate column stalk wire?) and connect the supply to the lights and the feed to the fat red from the battery???...

 

as you have guessed by now this is all new stuff to me an i appreciate the help :boohoo:

[Longboarder]

Your mention dim/dip. Sounds like you are using sierra fuse box, stalks and loom. If thats the case then 'if it aint broke'. There are four relays already working on front lights.

If you are making up your own loom and fuse box then think of a relay as an electricaly switched switch. There are several layouts of relay apart from a simple on/off. The commonest on/off should have a supply appropriate to the load, to terminal 30 and then 87 connects to the load then to earth. Terminals 85, 86 are the switching circuit. You can put in as much or as little as you want. i.e. ignition on live, to headlamp on/of switch, to terminal 85 then 86 to dip switch,to earth gives an on/off capability only when ignition and headlamp switch is on.

Difficult to make it sound as simple as it is and Haynes often makes it harder.

 

Nigel