Jase Posted June 30, 2021 Author Report Share Posted June 30, 2021 Finally just checked, the 35amp fuse is fine and if I check this to the battery I get approx 12v, changed the fuse as well. Now if I check the live purple the reading is all over the place 100+ could it be the relay? Quote Link to post Share on other sites
RobH Posted June 30, 2021 Report Share Posted June 30, 2021 (edited) Your meter is showing 0.5mV (i.e next to nothing)- what are you measuring? What do you mean by "check this to the battery" ? where exactly did you connect the meter and what range was it on? When you get "100+" on the purple wire is that Ohms and if so where are you connecting the meter? Edited June 30, 2021 by RobH Quote Link to post Share on other sites
Jase Posted June 30, 2021 Author Report Share Posted June 30, 2021 Just now, RobH said: Your meter is showing 0.5mV - what are you measuring? What do you mean by "check this to the battery" ? where exactly did you connect the meter and what range was it on? When you get "100+" on the purple wire is that Ohms and if so where are you connecting the meter? It's just sitting on the car in the photo, the leads are underneath. I'm no expert with this, it was set as per picture. I tried the black lead on the negative terminal of the battery, the bodywork and the earth lead going to the switch. In terms of the purple wire I have an extension that was going to the switch, I just popped the red terminal in there. Quote Link to post Share on other sites
RobH Posted June 30, 2021 Report Share Posted June 30, 2021 OK - with the meter set to DC volts as it is, with the black meter lead on earth and the red meter lead on on the purple wire connection you should have a constant 12V. Move the red meter lead to the purple/black wire on the relay you should also see 12V which shows the relay coil is OK. Get a piece of wire, remove the purple/black wire from the relay and short that relay terminal to earth ( be careful not to earth either of the other terminals). The relay should pull in and the horn should sound. If it does, the fault is in the switch circuit connected to the purple/black wire. If the horn doesn't sound and the relay doesn't click the relay is definitely faulty. If the relay clicks but there is no horn it's possible the relay contact is faulty or maybe the horn isn't earthed. Pull the yellow/purple wire off the relay and briefly touch it to the purple wire connection - the horn should sound. (There may be a spark when you do that, which is a surprise but nothing to worry about.) If the horn sounds, the relay contacts must be faulty. If it doesn't the fault is either in the horn or it isn't earthed. Quote Link to post Share on other sites
Jase Posted June 30, 2021 Author Report Share Posted June 30, 2021 2 minutes ago, RobH said: OK - with the meter set to DC volts as it is, with the black meter lead on earth and the red meter lead on on the purple wire connection you should have a constant 12V. Move the red meter lead to the purple/black wire on the relay you should also see 12V which shows the relay coil is OK. Get a piece of wire, remove the purple/black wire from the relay and short that relay terminal to earth ( be careful not to earth either of the other terminals). The relay should pull in and the horn should sound. If it does, the fault is in the switch circuit connected to the purple/black wire. If the horn doesn't sound and the relay doesn't click the relay is definitely faulty. If the relay clicks but there is no horn it's possible the relay contact is faulty or maybe the horn isn't earthed. Pull the yellow/purple wire off the relay and briefly touch it to the purple wire connection - the horn should sound. (There may be a spark when you do that, which is a surprise but nothing to worry about.) If the horn sounds, the relay contacts must be faulty. If it doesn't the fault is either in the horn or it isn't earthed. Thanks, a little more info, the horns have been working fine so it isn't something I moved about. I did pop the multimeter on each relay terminal to check and I was getting a similar reading to the purple wire but I was getting a 12v reading from the inline fuse. I think I might just get a new relay to be on the safe side. Are there any recommendations for relays or just order one from the usual supplier? Thanks for the swift reply. Jason Quote Link to post Share on other sites
RobH Posted June 30, 2021 Report Share Posted June 30, 2021 (edited) I think the usual supplier ones are as good as any. I expect all the suppliers get them from the same maker anyway. If you did just this bit it will show you whether the relay is working: Get a piece of wire, remove the purple/black wire from the relay and short that relay terminal to earth ( be careful not to earth either of the other terminals). The relay should pull in and the horn should sound. If it does, the fault is in the switch circuit connected to the purple/black wire. Edited June 30, 2021 by RobH Quote Link to post Share on other sites
Jase Posted June 30, 2021 Author Report Share Posted June 30, 2021 Thanks, just picked up another thread on the relays, I'll follow your advice from that one as well. Will dismantle this one and see if I can clean it up. Finally, if I just remove the yellow wire and purple/black wire from the relay and tap them together the horn should sound? Thank you Quote Link to post Share on other sites
RobH Posted June 30, 2021 Report Share Posted June 30, 2021 1 minute ago, Jase said: Finally, if I just remove the yellow wire and purple/black wire from the relay and tap them together the horn should sound? No that will just earth the horn and nothing will happen. You would need to touch the purple/yellow to purple. Quote Link to post Share on other sites
Jase Posted June 30, 2021 Author Report Share Posted June 30, 2021 11 minutes ago, RobH said: No that will just earth the horn and nothing will happen. You would need to touch the purple/yellow to purple. So basically C2 and C5 connections from the relay? Quote Link to post Share on other sites
RobH Posted June 30, 2021 Report Share Posted June 30, 2021 Should be C1 (horn) to C2 (supply). The other terminal is W1 Quote Link to post Share on other sites
Jase Posted June 30, 2021 Author Report Share Posted June 30, 2021 Thanks Quote Link to post Share on other sites
Jase Posted July 1, 2021 Author Report Share Posted July 1, 2021 Thanks for the advice, the relay is shot, just touched the purple and yellow and purple together and horns, earthed just the purple and black and nothing. Time to see if I can repair this one Quote Link to post Share on other sites
stuart Posted July 1, 2021 Report Share Posted July 1, 2021 1 hour ago, Jase said: Thanks for the advice, the relay is shot, just touched the purple and yellow and purple together and horns, earthed just the purple and black and nothing. Time to see if I can repair this one Ive just had to do the same on that one I put the picture on earlier in this thread, You can carefully bend the tabs up to get the cover off then what you`ll find is the contact between the copper wound reel and the contact above needs a little clean off with some fine sandpaper (dont use w/dry as it leaves conductive dust) blow out the dust and refit the cover. If its completely burnt out then make sure you get a 3 terminal horn relay to replace it, someone may have an original one which do last a lot longer. Stuart. Quote Link to post Share on other sites
Jase Posted July 1, 2021 Author Report Share Posted July 1, 2021 Good news, tried with a basic clean of all terminals and it has started working again. Thank you Quote Link to post Share on other sites
Jase Posted July 1, 2021 Author Report Share Posted July 1, 2021 On to the next issue, I’m getting water ingress and not just a little, new soft top fitted so I’m pretty sure it is fairly good, would expect some leakage but getting a lot of water in the car at the moment. Parked her on thesloped part of the drive and left for a few days to find literally a 15cm deep puddle behind the rear seat. Could it the windscreen seal letting in water? Only looking for short term fixes until I take her off the road for a restoration. Some pics of the floor well etc Quote Link to post Share on other sites
stuart Posted July 6, 2021 Report Share Posted July 6, 2021 Most likely the plenum or the plenum drain, look up under the dash in in front of the fresh air vents and see if the outer end of the plenum is rotten or the tube from it and out through the side kick panel is missing/rotted away. Stuart Quote Link to post Share on other sites
Jase Posted July 7, 2021 Author Report Share Posted July 7, 2021 Looks like it has rotted, what is the normal fix for this without a strip down? Mastik? Silicon? How does the water get to that point? Quote Link to post Share on other sites
stuart Posted July 7, 2021 Report Share Posted July 7, 2021 Fibreglass/ Bridgeagap is favourite for a quick fix, water enters through the vent flap and runs down to each end of the plenum, those drain tubes actually stick up slightly inside the base of plenum so if the car isnt used for a long time or the air vents arent opened to allow airflow to dry it out thats what happens, I have repaired quite a few, luckily 4/4a dont rot out as bad as 5/6 as they dont have the benefit of any airflow as their vent system all goes through the heater box so often not only the plenum rots out but the bulkhead in front does too. Stuart. Quote Link to post Share on other sites
Jase Posted July 7, 2021 Author Report Share Posted July 7, 2021 Thanks Stuart, I’ll open up the vents. Should be an interesting repair when I start Quote Link to post Share on other sites
John L Posted July 7, 2021 Report Share Posted July 7, 2021 I had a problem also there, cleaned it up as best as possible, and used fibre glass resin, and matting, a couple of coats to make a good seal, it was the best I could do upside down!, just keep the vent flap closed when raining! At least it stops getting your trousers and legs wet! John Quote Link to post Share on other sites
stuart Posted July 8, 2021 Report Share Posted July 8, 2021 13 hours ago, Jase said: Thanks Stuart, I’ll open up the vents. Should be an interesting repair when I start Im away at the moment but if you search for plenum repairs on the 5 or 6 forums Ive posted some pictures there before now of the amount of repairs needed on them, luckily its easier on a 4/4a due to the access through the air vent. Stuart. Quote Link to post Share on other sites
Jase Posted July 8, 2021 Author Report Share Posted July 8, 2021 32 minutes ago, stuart said: Im away at the moment but if you search for plenum repairs on the 5 or 6 forums Ive posted some pictures there before now of the amount of repairs needed on them, luckily its easier on a 4/4a due to the access through the air vent. Stuart. Thank you Quote Link to post Share on other sites
Jase Posted July 10, 2021 Author Report Share Posted July 10, 2021 Huge amount of bodywork to do some time in the future but she still shines up nicely with rust bubbles and cracks in the paint. Quote Link to post Share on other sites
stuart Posted July 11, 2021 Report Share Posted July 11, 2021 20 hours ago, Jase said: Huge amount of bodywork to do some time in the future but she still shines up nicely with rust bubbles and cracks in the paint. Its called Patina! You`ll never reproduce it Stuart. Quote Link to post Share on other sites
Jase Posted July 12, 2021 Author Report Share Posted July 12, 2021 And lots of it Best thing is it gets used all of the time. Quote Link to post Share on other sites
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