mcratchet1 Posted November 30, 2018 Share Posted November 30, 2018 I have 2006 Mack mr688s (032711) with blink code 4-2, im assuming it has something to do with fan clutch because its staying engaged. I just put a new clutch on about a month ago, anybody have a schematic or advise? Thanks!! Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/ Share on other sites More sharing options...
steeler Posted December 2, 2018 Share Posted December 2, 2018 You should have a constant 12v at one wire of the fan solenoid, the other wire is a ground signal from the ecu to disengage the fan. It could be as simple as a blown fuse (don't quote me but #41 I think?) Or could be a break in either the hot wire or ground. I've seen many that were broken wires, rather than chase the mess around and on top of the transmission, I just rewired, bypassing part of the harness. I don't have a schematic with me right now, but can give you pin numbers Monday if you still need them. Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410503 Share on other sites More sharing options...
mcratchet1 Posted December 3, 2018 Author Share Posted December 3, 2018 ok thanks did you run a new wire straight from ecu if so i could use the pin# for the ground if you have it Thanks Again!! Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410576 Share on other sites More sharing options...
steeler Posted December 4, 2018 Share Posted December 4, 2018 Yes, if you aren't getting the ground from ecu, I ran a new wire from eco to fan solenoid. My daughter was sick this morning so I stayed home today, but I'll get the info in the morning. Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410621 Share on other sites More sharing options...
steeler Posted December 4, 2018 Share Posted December 4, 2018 Pin number 9 at ecu connector j1(the top one) is your ground signal to turn fan off. Before you start splicing, check that wire for continuity to the fan solenoid. Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410660 Share on other sites More sharing options...
mcratchet1 Posted December 5, 2018 Author Share Posted December 5, 2018 ok Thanks i will give it a try Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410704 Share on other sites More sharing options...
mcratchet1 Posted December 5, 2018 Author Share Posted December 5, 2018 I forgot to ask is this the one on the engine or inside truck? Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410705 Share on other sites More sharing options...
steeler Posted December 5, 2018 Share Posted December 5, 2018 On the engine Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410708 Share on other sites More sharing options...
mcratchet1 Posted December 6, 2018 Author Share Posted December 6, 2018 Thanks, Steeler that did that job!!!!😅 Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410780 Share on other sites More sharing options...
steeler Posted December 6, 2018 Share Posted December 6, 2018 No problem. Glad you fixed it! Quote Link to comment https://www.bigmacktrucks.com/topic/54924-need-help-with-4-2-blink-code-please/#findComment-410784 Share on other sites More sharing options...
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