Headlight issues

[Dave8514]

Hi, I’ve recently purchased a Robin Hood 2b (sierra based assuming 1988 based on plate) all worked fine for 2 days when I noticed I have no dipped beam. Main beam works on flash mode and sidelights work.

 

I have power at the switch but none at the fuse. The relay has tested at 58 ohms which seems a little on the low side? I have power at the relay. 
 

to test my theory that the relay is at fault I want to buy a new one but I’m struggling to find the correct one new. 5 pin 12v 2x20a

also looking at Halfords selection of 5 pin relays is it a continuous relay or not I’m struggling to find the relevant information online.

 

if anyone can help it would be much appreciated Dave 

[Sparepart]

Here is a link to a site where you can download a copy of the service and repair manual for the Sierra, you might find it useful for lots of questions that you might have.

https://musse67.mbnet.fi/Taunus/Korjausoppaat/

The wiring diagram for an 1988 model for lights is on page 13-40 (Diagram 2), there you can see the dip beam relay (37). You could check if the relay is the problem by making the connection that the relay would make by connecting pin 87 to pin30 which will provide +12v to the yellow wire that runs to the bus bar for both fuses 3 and 4. Each of these fuses should be 10 amps, so the relay needs to switch 20 amps. I'll pass on what a "continuous" relay is. I have a similar circuit, and have purched a fusebox that contains the sort of relay you need. It is rated at 30 amps for the switch when energised, and 40 amps for the switch when not energised (using the centre pin 87a, which is not connected in this application) I have measered the resistance between pins 86 and 85 and it is 80 ohms. Hope this helps. P.S. I looked at Halfords and this link is for the sort of relay you could try.

https://www.halfords.com/tools/fuses-electricals-and-fixings/electricals/halfords-hef557-relay-12v-30a-5-pin-184161.html

Edited February 5, 2022 by Sparepart
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[Dave8514]

That’s fantastic thank you I’ll check it out when I get chance much appreciated

[Dave8514]

It was the relay new one fitted lights now work, I just need to slowly work through the rest of the electrical issues now, thank you for the help