Nick Jones Posted April 4, 2014 Share Posted April 4, 2014 Following from my OD issues I have established that the coil on the car had only the holding coil working - not enough to pull it in.Now dismantled (that top screw >:() and it turns out that it is another victim of rubbish rubber (the waterproof sleeve has perished) and the switch was slightly corroded as a consequence (that big puddle again)Switch now cleaned and I seem to get 0.8 - 1 ohm in relaxed position (pull-in and holding coils) and 13 - 14 ohms pulled in (holding coil only). Seems quite reasonable and likely to produce a 1A holding current as per book.Just to confuse myself (!) I also measured the new solenoid I have thinking it would be the same but.....I seem to get 0.8 - 1 ohm in relaxed position (pull-in and holding coils) and but only 3 - 4 ohms pulled in (holding coil only). This seems too low too me.Can't find any figures for coil resistance, only for currents. My multimeter only goes up to 10A........Anyone have any figures or previous dealings?CheersNick Quote Link to comment Share on other sites More sharing options...
piman Posted April 4, 2014 Share Posted April 4, 2014 Hello Nick,at rest, the new solenoid gives 4 to 5 ohms so a current of around 3 to 2.4 amps at a nominal 12 volts, does that sound too high, I don't think it is? You may still have a poor contact on your old coil?Alec Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 4, 2014 Author Share Posted April 4, 2014 Alec,I agree that the current won't be crazy high with the new solenoid, but all the information I can find suggests it should be 1 - 1.5A, which fits better with the 13 ohms of the old solenoid.Also various online sources suggest that the 0.8 - 1 ohm for the combined coils and is correct and that 11 - 15 ohms (various sources) is normal for the holding coil.The holding coil is permanently in circuit so no contacts involved.I've now coated the switch end of the old solenoid with a generous layer of Tiger Seal to keep the water out and will try that back on once dried. I'll maybe also try the new one on there and see what current it pulls once in (will have to figure out a way of bypassing the ammeter while it pulls in!)CheersNick Quote Link to comment Share on other sites More sharing options...
piman Posted April 5, 2014 Share Posted April 5, 2014 Hello Nick, I don't have any figures to hand but as the 'A' type needs a relay I would have thought more than 1 to 1.5a, I know it's inductive but so is the 'J' type which doesn't use a relay."(will have to figure out a way of bypassing the ammeter while it pulls in!)"Precisely how low current ammeters measure high current in industrial situations, its called a shunt and is connected directly across both ammeter terminals, so that a portion of the current passes through the ammeter and the rest through the shunt. Now industrial shunts are accurate and expensive, but a simple test rig with headlights should give you some figures using a bit of cable and some time. I.e. a 60 watt lamp connected with the ammeter should give around 5 amps, try then with a piece of wire across the ammeter and see what you get. if say the reading is now 2.5 amps or so you've doubled the range of the ammeter. (it's unlikely to be as convenient a figure as that but that's the principle.)Alec Quote Link to comment Share on other sites More sharing options...
Hogie Posted April 5, 2014 Share Posted April 5, 2014 I seem to remeber that the hold in current was close to 1amp.The relay may well be TRiumph belt and braces and dispensed with on later versions.Be careful with the rubber boot. My last replacement (about 10 years ago) was soooo stiff that it held the O/D in when it should have been disengaged.reversing was interesting but thankfully uneventful.The finger of a decent Marigold would substitute nicely.Roger Quote Link to comment Share on other sites More sharing options...
piman Posted April 5, 2014 Share Posted April 5, 2014 Hello Nick, "at rest, the new solenoid gives 4 to 5 ohms so a current of around 3 to 2.4 amps at a nominal 12 volts, does that sound too high, I don't think it is? You may still have a poor contact on your old coil?I just re read what I posted above and it's utter rubbish; you're not the only one confused. Your original query seems to add up. The initial current before the switch makes is high (12 amps or so) so explains the need for a relay.Alec Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 5, 2014 Author Share Posted April 5, 2014 I'll try them both on a battery before crawling under the car. Access to the top bolt is rubbish and putting it in once is likely to be more than enough!I think we may be talking about different rubber boots Roger? There is a waterproofing rubber sleeve over the outside, perished to shreds after about 3.5 years. The new solenoid also came with a boot for the plunger. I can't see what purpose it serves though and it doesn't seem to fit properly so I'll probably leave it out - which seems to be what I did last time 'cause there wasn't one on the old one.Nick Quote Link to comment Share on other sites More sharing options...
Hogie Posted April 5, 2014 Share Posted April 5, 2014 Ah yes - the outer casing rubber sleeve.Do we know why TRiumph rubber parts are rubbish.Roger Quote Link to comment Share on other sites More sharing options...
Richard B Posted April 5, 2014 Share Posted April 5, 2014 2601 wrote:Do we know why TRiumph rubber parts are rubbish.EU rules, not allowed to use the nasty substances that make for good rubber. ;) Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 5, 2014 Author Share Posted April 5, 2014 "EU rules, not allowed to use the nasty substances that make for good rubber. "I don't buy that - the OEMs manage!Anyway,"old" solenoid pulls 0.9A when pulled in on the holding coil when supplied at 12.6vNew solenoid pulls 3.1A under the same conditions. While this isn't huge, it is 3 x the various book figures I can find, so I've put the old one back after a clean of the contacts and waterproofing with Tiger Seal. It's working fine at the moment.What next.....?Nick Quote Link to comment Share on other sites More sharing options...
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