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Ignition relay current rating
wylliezx9r - 22/1/13 at 01:41 PM

Im looking at getting the starter relay sorted for my f20c installtion, does anybody know what this should be rated at ? I have used google but can't find anything conclusive, I'm guessing @ 30 amps ?

Many thanks

Dan

snowy2 - 22/1/13 at 02:21 PM

Starter relay? If you refer to the solinoid (a relay) its rated in the 100‘s of amps!
If you refer to a relay to activate the solinoid (a relay) then you don't need one!

wylliezx9r - 22/1/13 at 02:47 PM

quote:
Originally posted by snowy2
Starter relay? If you refer to the solinoid (a relay) its rated in the 100‘s of amps!
If you refer to a relay to activate the solinoid (a relay) then you don't need one!


I'm talking about a relay to activate the solenoid, the origional s2000 wiring uses one (activated by a pretty starter switch) that is why i thought it was needed.

robinj66 - 22/1/13 at 03:13 PM

Starter relay in Ford Sierra is 70 amp if that helps.

Brett Jones - 22/1/13 at 04:32 PM

I've just search through the manual and it does not state anywhere what the current rating is of the relay, it only states thats its an "open type A" relay. Your best bet would be to post this question on the s2ki forum.

snowy2 - 22/1/13 at 06:09 PM

A relay to operate a solenoid? wierd.......any relay should do the job, but if it is as much as 70A i would be amazed, lets suppose it is.... they are common on Vauxhalls (Astra's and Corsa's) any scrappers will have loads.
to be honest if your using a key to operate the starter solenoid then you dont need to relay it, its a level of paranoia that leads to air bags and SIPS etc.

AdrianH - 22/1/13 at 06:44 PM

A relay can be a good idea in the long term where it becomes easier to swap a relay then an ignition switch, or other as the contacts fail due to arcing with back emf etc.

I know a diode can help to stop this and I would say a typical 30 amp relay would be ample for the starter solenoid, the current required is only an amp or so, but the larger relay the bigger contacts and the longer it would last.
IMHO of course.

Adrian

p.s.

relays are also a good point to allow alarm systems or PATS to be connected to provide another way to immobilize an engine. Typically Ford ECU's to start the engine the ignition switch provides 12 Volts to one side of the coil. The ECU ground the other side on recognition of the correct key.

[Edited on 22-1-13 by AdrianH]

GOJO - 22/1/13 at 07:43 PM

30 amp for pin will be fine