{"product_id":"genuine-mack-2mr2149-relay-switch-5-pin-nos","title":"Genuine Mack 2MR2149 Relay Switch | 12V 35\/20 AMP 5-Pin | Fits Horn \u0026 Engine Brake","description":"\u003cp data-path-to-node=\"5\"\u003e\u003cb data-path-to-node=\"5\" data-index-in-node=\"0\"\u003eRestore electrical reliability with this Genuine OEM Mack Relay Switch.\u003c\/b\u003e\u003c\/p\u003e\n\u003cp data-path-to-node=\"6\" id=\"p-rc_8a592415ea312710-129\"\u003eThe \u003cb data-path-to-node=\"6\" data-index-in-node=\"4\"\u003eMack 2MR2149\u003c\/b\u003e (often referenced as 2MR2149M) is a versatile 12V multi-purpose relay used across various Mack truck platforms. \u003cspan class=\"citation-131 citation-end-131\"\u003eFeaturing a standard 5-pin configuration and rated for 35\/20 Amps, this relay is a critical component for high-draw systems such as horns, ignition feeds, and engine brake disable circuits.\u003csup class=\"superscript embedded\" data-turn-source-index=\"1\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c\/p\u003e\n\u003cp data-path-to-node=\"7\"\u003eUsing a genuine Mack Bulldog part ensures proper resistance and switching speeds that aftermarket \"universal\" relays often fail to match, preventing electrical gremlins and protecting your truck's wiring harness.\u003c\/p\u003e\n\u003cp data-path-to-node=\"8\"\u003e\u003cb data-path-to-node=\"8\" data-index-in-node=\"0\"\u003eKey Features:\u003c\/b\u003e\u003c\/p\u003e\n\u003cul data-path-to-node=\"9\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,0,0\"\u003e\u003cb data-path-to-node=\"9,0,0\" data-index-in-node=\"0\"\u003eGenuine Mack OEM:\u003c\/b\u003e Direct replacement for part number \u003cb data-path-to-node=\"9,0,0\" data-index-in-node=\"53\"\u003e2MR2149\u003c\/b\u003e and \u003cb data-path-to-node=\"9,0,0\" data-index-in-node=\"65\"\u003e2MR2149M\u003c\/b\u003e.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,1,0\" id=\"p-rc_8a592415ea312710-130\"\u003e\u003cspan class=\"citation-130\"\u003e\u003c\/span\u003e\u003cb data-path-to-node=\"9,1,0\" data-index-in-node=\"0\"\u003e\u003cspan class=\"citation-130\"\u003eHigh-Performance Specs:\u003c\/span\u003e\u003c\/b\u003e\u003cspan class=\"citation-130 citation-end-130\"\u003e 12 Volt, 5-Terminal, 35\/20 Amp rating.\u003csup class=\"superscript embedded\" data-turn-source-index=\"2\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,2,0\"\u003e\u003cb data-path-to-node=\"9,2,0\" data-index-in-node=\"0\"\u003eVersatile Application:\u003c\/b\u003e Commonly used for Horns, Engine Brakes, Ignition Feed, and accessory circuits.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,3,0\" id=\"p-rc_8a592415ea312710-131\"\u003e\u003cspan class=\"citation-129\"\u003e\u003c\/span\u003e\u003cb data-path-to-node=\"9,3,0\" data-index-in-node=\"0\"\u003e\u003cspan class=\"citation-129\"\u003eCondition:\u003c\/span\u003e\u003c\/b\u003e\u003cspan class=\"citation-129\"\u003e \u003c\/span\u003e\u003cb data-path-to-node=\"9,3,0\" data-index-in-node=\"11\"\u003e\u003cspan class=\"citation-129\"\u003eNew Old Stock (NOS)\u003c\/span\u003e\u003c\/b\u003e\u003cspan class=\"citation-129 citation-end-129\"\u003e — Unused, original OEM quality.\u003csup class=\"superscript embedded\" data-turn-source-index=\"3\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-path-to-node=\"10\"\u003e\u003cb data-path-to-node=\"10\" data-index-in-node=\"0\"\u003eInterchange \u0026amp; Cross-Reference:\u003c\/b\u003e\u003c\/p\u003e\n\u003cul data-path-to-node=\"11\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"11,0,0\"\u003e\u003cb data-path-to-node=\"11,0,0\" data-index-in-node=\"0\"\u003eMack \/ Volvo:\u003c\/b\u003e 2MR2149M, 2MR2154M, 3968336, 25195197, 25082390.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"11,1,0\"\u003e\u003cb data-path-to-node=\"11,1,0\" data-index-in-node=\"0\"\u003eFreightliner:\u003c\/b\u003e 23-13265-001.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"11,2,0\"\u003e\u003cb data-path-to-node=\"11,2,0\" data-index-in-node=\"0\"\u003eNavistar \/ International:\u003c\/b\u003e 3516015, 3516015C1, 2602142, 2602142C1.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-path-to-node=\"11,3,0\" id=\"p-rc_8a592415ea312710-132\"\u003e\u003cb data-path-to-node=\"11,3,0\" data-index-in-node=\"0\"\u003eOther:\u003c\/b\u003e\u003cspan class=\"citation-128 citation-end-128\"\u003e Song Chuan 301-1C-D-R1, PAI MSW-1237, TruckAC T5299\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-path-to-node=\"6,0\"\u003e \u003c\/p\u003e\n\u003cp data-path-to-node=\"6,0\"\u003e\u003cb data-path-to-node=\"6,0\" data-index-in-node=\"0\"\u003eCommon Slot Locations:\u003c\/b\u003e\u003c\/p\u003e\n\u003cul data-path-to-node=\"6,1\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,1,0,0\"\u003e\u003cb data-path-to-node=\"6,1,0,0\" data-index-in-node=\"0\"\u003eMack Granite (GU):\u003c\/b\u003e Typically found in slots \u003cb data-path-to-node=\"6,1,0,0\" data-index-in-node=\"44\"\u003eR1 (Horn)\u003c\/b\u003e and \u003cb data-path-to-node=\"6,1,0,0\" data-index-in-node=\"58\"\u003eR4 (Engine Brake)\u003c\/b\u003e.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,1,1,0\"\u003e\u003cb data-path-to-node=\"6,1,1,0\" data-index-in-node=\"0\"\u003eMack Vision (CXU):\u003c\/b\u003e Frequently used for \u003cb data-path-to-node=\"6,1,1,0\" data-index-in-node=\"39\"\u003eMarker Lamps\u003c\/b\u003e and \u003cb data-path-to-node=\"6,1,1,0\" data-index-in-node=\"56\"\u003eIgnition Switched Power\u003c\/b\u003e.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,1,2,0\"\u003e\u003cb data-path-to-node=\"6,1,2,0\" data-index-in-node=\"0\"\u003eIntermittent Electrical Tip:\u003c\/b\u003e If your horn or engine brake works only \"sometimes,\" the internal contacts of this relay are likely pitted or burnt. Replacing with a \u003cb data-path-to-node=\"6,1,2,0\" data-index-in-node=\"163\"\u003eGenuine Mack 2MR2149\u003c\/b\u003e ensures proper amperage draw and protects your ECM from voltage spikes.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Mack","offers":[{"title":"Default Title","offer_id":46035863339242,"sku":"GC4C5-3-051026","price":9.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0708\/2206\/8458\/files\/Genuine_Mack_2MR2149_5-pin_12V_relay_switch_for_commercial_trucks..png?v=1778416577","url":"https:\/\/bboverstockparts.com\/products\/genuine-mack-2mr2149-relay-switch-5-pin-nos","provider":"BB Overstock Parts","version":"1.0","type":"link"}