Lotus Elan

S4 Relays

PostPost by: saildrive2001 » Tue Aug 25, 2009 8:28 pm

I have three relays on my S4, one for the main beam, one for the dipped beam & one for the headlamp flasher function. The main & dip relays have a coil resistance of 41 ohms but the flasher relay has a coil resistance of only 4.8 ohms. Does anyone know if this is correct or do I have a bad relay? These are the original relays so if I need to replace them I would like to replace with the same.
interestingly they all have differnt connector locations on the base.
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PostPost by: wojeepster » Wed Aug 26, 2009 5:58 am

12v divided by 4.8 ohms is 2.5 amps. That seems awfully high to me

12v divided by 41ohms is .29amps a more reasonable value I think the relay is bad.
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PostPost by: paddy » Wed Aug 26, 2009 8:43 am

I seem to remember that a high current through the relay was necessary to make the original-style flasher unit flash. The flasher units are designed to flash when a normal "indicator" light load is drawn through it. (2 x 25W = 50W = 4 amps). I think some people have reported changing the original relay with a new one that draws a lot less current and then finding that the headlights don't flash any more. This can be fixed by fitting a newer style flasher unit that isn't sensitive to the current drawn through it.

If you want to keep everything original, and keep original flasher unit, it might be easier to service the relay unit than to find a new one to the original spec (although I haven't tried taking one apart).

The flasher and relay from mine are long since disappeared so perhaps someone else can verify.

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PostPost by: saildrive2001 » Wed Aug 26, 2009 1:03 pm

I have taken the relays apart, the plastic housing is only attached by two very small philips headed screws. All three relays work when connected to 12V although I haven't verified the current draw. I think that you have a point Paddy about the flasher unit needing a larger current to work. The old style units had a bimetalic strip which heated up & cooled as it opened & closed the contacts.
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PostPost by: neilsjuke » Thu Aug 27, 2009 12:29 pm

Lucas 6RA Relays windings are about 70 ohms +/- 5 Thats the old ones not the new overseas rubbish copies
You can fit new relays inside the Lucas metal covers from IMO Fabricante
IMO SRZ-1CT-DL-12VDC - RELAY, SPCO, 12VDC; Series:SRZ; Voltage, Coil DC Nom:12V; Coil Resistance:90ohm; No. of Poles:1; Contact Configuration:SPCO; Voltage, Contact DC Max:27V; Max Contact Current DC:30A;

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