- How to Test a Relay - 12 Updates
- OT Best way to protect bare metal surface for use in woodworking ? - 1 Update
| Adam <adam@no_thanks.com>: Feb 10 12:31AM My car's blower motor relay may be bad (or the cause of noisy fan). So I found the following video... How to Test a Relay the Correct Way https://www.youtube.com/watch?v=ire7vyDqelg However, I don't have a cordless drill battery (used in the video). Will the following battery charger... UPG D1724 Sealed Lead Acid Battery Charger (6V/12V Switchable Single- Stage With Alligator Clips) https://www.amazon.com/gp/product/B001G8AIMU/ref=ox_sc_act_title_1? smid=A10QFO4IXVZNRN&psc=1 work ? Other frugal ideas ? |
| Tom Biasi <tombiasi@optonline.net>: Feb 09 08:06PM -0500 On 2/9/2020 7:31 PM, Adam wrote: > https://www.amazon.com/gp/product/B001G8AIMU/ref=ox_sc_act_title_1? > smid=A10QFO4IXVZNRN&psc=1 > work ? Other frugal ideas ? An automotive cube uses 12 volts. Any 12 volt DC source will see if the coil pulls in the contacts. There is much more to checking a relay properly. Pull in current, dropout current, contact resistance, and more. But if just want to see if you can hear the armature pull in that it will do that. |
| Adam <adam@no_thanks.com>: Feb 10 01:38AM On Sun, 09 Feb 2020 20:06:16 -0500, Tom Biasi wrote: > Pull in current, dropout current, contact resistance, and more. > But if just want to see if you can hear the armature pull in that it > will do that. According to the video, I think I also need to check resistance. Will that battery charger on Amazon work ? |
| Tom Biasi <tombiasi@optonline.net>: Feb 09 09:34PM -0500 On 2/9/2020 8:38 PM, Adam wrote: >> will do that. > According to the video, I think I also need to check resistance. > Will that battery charger on Amazon work ? Any 12 vdc source will work. to check coil resistance you need an ohm meter. The relay in the video has a diode. So ohm meter polarity is important. In a proper test the diode characteristics would also be checked. |
| whit3rd <whit3rd@gmail.com>: Feb 09 07:32PM -0800 On Sunday, February 9, 2020 at 4:31:52 PM UTC-8, Adam wrote: > My car's blower motor relay may be bad (or the cause of noisy fan). > However, I don't have a cordless drill battery (used in the video). You have a car, with a battery that makes perfectly acceptable 12V. > UPG D1724 Sealed Lead Acid Battery Charger (6V/12V Switchable Single- > Stage With Alligator Clips) > work ? Maybe. It's possible to make chargers that don't generate +12V unless attached to a battery, or that turn off if/when peak voltage exceeds a full battery charge. |
| Adam <adam@no_thanks.com>: Feb 10 03:39AM On Sun, 09 Feb 2020 19:32:13 -0800, whit3rd wrote: >> My car's blower motor relay may be bad (or the cause of noisy fan). >> However, I don't have a cordless drill battery (used in the video). > You have a car, with a battery that makes perfectly acceptable 12V. Maybe best to just use the car battery then. Just connect with alligator clips. |
| John Robertson <spam@flippers.com>: Feb 09 10:40PM -0800 On 2020/02/09 4:31 p.m., Adam wrote: > https://www.amazon.com/gp/product/B001G8AIMU/ref=ox_sc_act_title_1? > smid=A10QFO4IXVZNRN&psc=1 > work ? Other frugal ideas ? OK, the video is fine as far as it goes, but it really is not the last word in properly testing a relay as the real test is do the contacts work under load. So, what I would do if I was suspicious of this relay, and I didn't want to remove the cover to visually inspect the contacts, is I would first hook the relay to 12VDC with the +12VDC source connected to terminal 86, and the negative side of the 12VDC supply to terminal 87. The diode shown in the wiring diagram on the relay shows that the relay will not operated if these are wired backwards as the diode would block the current flow. Next I would find a load of a couple of amps - perhaps a car light bulb. You want something that is 24Watts - which is roughly 2 amps at 12VDC. You then wire up the lamp so that the switch inside the relay - contacts 30 & 87 - are in series with the light and the 12VDC source. And you also hook up a voltmeter across terminals 30 & 87 - to measure voltage across the contacts. Now power/energize the relay - the 12V lamp should light and the voltage across the terminals 30 & 87 should drop to as close to zero VDC as possible. Anything under 0.100VDC would probably be OK, with actually 0.00VDC being the ideal. If you see around 0.50 or more VDC across those two terminals then the relay contacts are corroded and the relay is unlikely to operate anything drawing heavier current well at all. It should be replaced. Without testing relay contacts under a reasonable load you really don't know if the contacts will operate well enough to do the job that is required. These relays are usually rated at around 25A, so a 2A load is roughly ten percent and will give you some idea of the contact condition if you measure the voltage drop across them. John :-#)# |
| John Robertson <spam@flippers.com>: Feb 09 10:41PM -0800 On 2020/02/09 4:31 p.m., Adam wrote: > https://www.amazon.com/gp/product/B001G8AIMU/ref=ox_sc_act_title_1? > smid=A10QFO4IXVZNRN&psc=1 > work ? Other frugal ideas ? Oh, and it is really unlikely that a relay will cause a fan to be noisy - that is more likely bearing failure, or foreign matter in the motor assembly somewhere... John :-#)# |
| tabbypurr@gmail.com: Feb 10 03:09AM -0800 On Monday, 10 February 2020 00:31:52 UTC, Adam wrote: > https://www.amazon.com/gp/product/B001G8AIMU/ref=ox_sc_act_title_1? > smid=A10QFO4IXVZNRN&psc=1 > work ? Other frugal ideas ? Nearly all relay failures are switching points gone high resistance. So test that. To power the coil... you have a car battery right? |
| Adam <adam@no_thanks.com>: Feb 10 12:27PM On Sun, 09 Feb 2020 22:41:33 -0800, John Robertson wrote: > - that is more likely bearing failure, or foreign matter in the motor > assembly somewhere... > John :-#)# Blower Motor https://us.lexusownersclub.com/forums/topic/61767-blower-motor/ Relays are cheap compared to other parts so I don't mind starting with the relay. |
| Adam <adam@no_thanks.com>: Feb 10 12:30PM On Mon, 10 Feb 2020 03:09:49 -0800, tabbypurr wrote: >> work ? Other frugal ideas ? > Nearly all relay failures are switching points gone high resistance. So > test that. To power the coil... you have a car battery right? Yes, I'll probably use the car battery. Hopefully, no shock. |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Feb 10 07:38AM -0800 Late in on this: a) The only way a relay could affect fan noise would be if it is chattering - thereby causing the fan to chatter. Brush-type DC motors are generally not fond of low-frequency intermittent voltage. b) And, if an automotive relay is in any way questionable - replace it outright. The alternative might be a 3:00 am breakdown during a blinding snowstorm. To this end, I know a number of individuals (including me) that carry spare relays for critical functions when on road-trips or off the beaten path. And, I know where those of that nature live in both vehicles. There is frugal - spending money wisely. There is parsimonious - which is frugality taken to the extreme. There is being miserly - which has high potential for negative consequences. Be frugal, and/but try not to be stupid about it. My road-trip "Spares Kit" includes: Fuel Pump, Headlight, and Main Systems relays. High and Low beam, turn-signal and brake lamps, if applicable. Fuses. Black electricians tape. Good gloves. Very, very good Jumper cables. Flat-fix x 2. Canvas tarp. Come to kindly terms with your Ass, for it bears you - John Muir. Peter Wieck Melrose Park, PA |
| Jeff Liebermann <jeffl@cruzio.com>: Feb 09 02:02PM -0800 On Thu, 6 Feb 2020 15:20:51 -0800, OtterGuy >What is the best way to protect bare steel metal surface (IT RUSTS >EASILY) for use in woodworking ? It is on a band saw. What part of the band saw? Steel, stainless, cast iron, pot metal, saw blade, etc???? It helps to know what you're trying to protect. Also, some of the coating methods I suggested below are not appropriate for some flavors of steel. >Bee's Wax ? >Suggestions please. Cold bluing or passivation is probably the easiest, cheapest, and least protective method of protecting steel. The problem with wood working machinery is that it will abrade away the surface coating, expose the underlying steel, and proceed to rust. Hot bluing is more durable but requires multiple layers of bluing: <https://www.wikihow.com/Blue-Steel> If you want better protection, I suggest: 1. Nickel electroplating. 2. Black chrome plating over nickel. 3. Powder coated paint. If you need the surface to absorb oil for lubrication, I suggest Parkerizing: <https://en.wikipedia.org/wiki/Parkerizing> Nickel plating, you can probably it do yourself at home. <https://www.caswellplating.com/electroplating-anodizing/nickel-plating-kits/nickel-electroplating-kits.html> The others, I suggest you send the unspecified band saw part to a plating shop and have them plate it. For powder coating paint: <https://www.eastwood.com/hotcoat-powder-coating.html> or ask at your local automobile paint shop. If you don't mind re-coating the steel part, try one of the rust inhibiting sprays or coatings. For example: <https://www.wd40.com/products/corrosion-inhibitor/> Also see: <https://www.finishing.com> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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