RowdyRebel Posted August 2, 2008 Share Posted August 2, 2008 Where'd Mack hide the sensor on the T2180B trans? I'm thinking that's why the backup light/alarm as well as the "R" idiot light quit working on me last week...but I can't see where any wires are coming out of the transmission other than for the speed sensor at the rear. Would it be on the top (out of sight)? If so, what's the best way to get to it? I'm thinking if it IS on the top, it would be easier to remove the rubber shift boot to go through the floor rather than work blind reaching up from underneath.......need to get it fixed before the mines decide to check and then refuse to let me go in to load...or before MSHA tries writing me a ticket for not having an operational backup alarm in the mine Worst case scenario (if I can't find the dang thing), I suppose I can rig something up that'll work by running a hot wire to the alarm from a switch inside the truck to manually turn on the buzzer whenever I need to back up, but I'd prefer to fix it right. Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/ Share on other sites More sharing options...
Noid93 Posted August 3, 2008 Share Posted August 3, 2008 yes, it is located up on the top of the trans. Easily acessable from the floor of the cab( especially on the ch/cl). Quote There Is No Replacement, For Displacement!!!!! Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21058 Share on other sites More sharing options...
RowdyRebel Posted August 4, 2008 Author Share Posted August 4, 2008 yes, it is located up on the top of the trans. Easily acessable from the floor of the cab( especially on the ch/cl).thanks Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21066 Share on other sites More sharing options...
RowdyRebel Posted August 12, 2008 Author Share Posted August 12, 2008 ...OK, so the new reverse sensor is in and it STILL isn't working ...no backup light, no backup alarm, and no "R" idiot light on the dash. Is there a fuse in that circuit anywhere that I should be looking for? Or should I be looking for a loose connection or short? Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21239 Share on other sites More sharing options...
Mackpro Posted August 12, 2008 Share Posted August 12, 2008 Fuse 18 does the back up lights on ch/cl up to 1998 or non Etech engines. On 1999 and up Etech engined models its fuse 42 out under the hood. Quote Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21241 Share on other sites More sharing options...
RowdyRebel Posted August 13, 2008 Author Share Posted August 13, 2008 Fuse 18 does the back up lights on ch/cl up to 1998 or non Etech engines. On 1999 and up Etech engined models its fuse 42 out under the hood.Thanks...found the burnt out fuse....now just gotta buy a tiny little 20 amp replacement. Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21255 Share on other sites More sharing options...
Rob Posted August 13, 2008 Share Posted August 13, 2008 Thanks...found the burnt out fuse....now just gotta buy a tiny little 20 amp replacement. A blown fuse is an indication, or result of a high current draw in the circuit it is protecting. There must be a problem in the circuitry that caused this result that needs addressed.Buy more than a single replacement until your troubleshooting reveals the reason for the blown fuse in the first place.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21259 Share on other sites More sharing options...
RowdyRebel Posted August 13, 2008 Author Share Posted August 13, 2008 A blown fuse is an indication, or result of a high current draw in the circuit it is protecting. There must be a problem in the circuitry that caused this result that needs addressed.Buy more than a single replacement until your troubleshooting reveals the reason for the blown fuse in the first place.RobAfter I bought the truck, I ran a wire from the hot wire going to the back-up alarm up to a switch on the dash and back down to the alarm so that I could shut it off when I'm backing into the driveway at 2 AM or anytime I'm in a truckstop....I was planning on retracing those wires to make sure they weren't rubbing on anything they...maybe it was just close enough to the 20 amps that the extra wire length along with the lighted switch was enough to blow it...not sure what the draw is on the back-up light/back-up alarm/idiot light is supposed to be...Truck's going to Mack over Labor Day weekend to get the overhead run and I'm going to have them quote me a price on getting that leak on the rear axle taken care of too...if I blow another fuse and can't find the reason by then, I'll have them trace the problem too....either that or I'll up the fuse to a 25 amp and see if that blows. I hate electrical problems Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21275 Share on other sites More sharing options...
Rob Posted August 13, 2008 Share Posted August 13, 2008 After I bought the truck, I ran a wire from the hot wire going to the back-up alarm up to a switch on the dash and back down to the alarm so that I could shut it off when I'm backing into the driveway at 2 AM or anytime I'm in a truckstop....I was planning on retracing those wires to make sure they weren't rubbing on anything they...maybe it was just close enough to the 20 amps that the extra wire length along with the lighted switch was enough to blow it...not sure what the draw is on the back-up light/back-up alarm/idiot light is supposed to be...Truck's going to Mack over Labor Day weekend to get the overhead run and I'm going to have them quote me a price on getting that leak on the rear axle taken care of too...if I blow another fuse and can't find the reason by then, I'll have them trace the problem too....either that or I'll up the fuse to a 25 amp and see if that blows. I hate electrical problems Determine the electrical load of the circuit before you up the protection via a larger fuse rating. I don't like electrical problems either but they have put food on the table for a good many years.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21276 Share on other sites More sharing options...
RowdyRebel Posted August 13, 2008 Author Share Posted August 13, 2008 Determine the electrical load of the circuit before you up the protection via a larger fuse rating. I don't like electrical problems either but they have put food on the table for a good many years.Robso far the 20 amp fuse is working...not like I have the switch turned on all the time...just when I'm at the mines or at a construction site which requires it...anyway, thanks for all the help. I never even thought to look for a second fuse box under the hood...looked at the one in the dash and didn't see a fuse burned out, so assumed it was the switch......how many more fuse boxes does this thing have? Just the 2? or is there another one hiding somewhere that I should be aware of in case there are more electrical fuses blown in the future? Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21278 Share on other sites More sharing options...
Rob Posted August 14, 2008 Share Posted August 14, 2008 so far the 20 amp fuse is working...not like I have the switch turned on all the time...just when I'm at the mines or at a construction site which requires it...anyway, thanks for all the help. I never even thought to look for a second fuse box under the hood...looked at the one in the dash and didn't see a fuse burned out, so assumed it was the switch......how many more fuse boxes does this thing have? Just the 2? or is there another one hiding somewhere that I should be aware of in case there are more electrical fuses blown in the future? There is usually just a pair of circuit protection "fuseblocks" in most motor vehicles. The underhood blocks are usually for the high current draw items like electric fans, window motors and such. That is why there are "Maxi" style fuses. They tend to be a "slo-blow" type of arrangement.It may be in your best interest to invest in an inexpensive inductive ammeter obtainable at most any parts store. These are not meant to be a permanent install. You just lay the trough on the backside onto the wire of the circuit you want to check with the circuit operating. The meter will give you a general idea of current draw in amperes. These are great because you don't have to break into the circuit.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21285 Share on other sites More sharing options...
Freightrain Posted August 14, 2008 Share Posted August 14, 2008 Was the old sensor dead shorted internally? That would have blown the fuse also, then after replacing the sensor it would take a new fuse to get it working again.Something to consider. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-21293 Share on other sites More sharing options...
Billy Vance Posted March 1, 2022 Share Posted March 1, 2022 Where is the back up light switch on a 2020 mack granite with the M drive transmission Quote Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-490676 Share on other sites More sharing options...
mikehumes2002 Posted September 17, 2022 Share Posted September 17, 2022 I am having the same issue on 2015 ch can't locate switch or fuse Quote Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-509667 Share on other sites More sharing options...
Joey Mack Posted September 17, 2022 Share Posted September 17, 2022 does it get its signal through the connectors on the side of the tranny, what is the issue? Quote Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-509673 Share on other sites More sharing options...
Joey Mack Posted September 17, 2022 Share Posted September 17, 2022 check fuse #34 in the EPDM.. the panel at the bottom left corner, behind where the clutch pedal would be.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-509676 Share on other sites More sharing options...
j.luis Posted April 28, 2023 Share Posted April 28, 2023 My back up light a mean the R reverse its not working and where can I find the sensor or the fuse in a mack vision cxn612 2007 Quote Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-530267 Share on other sites More sharing options...
Joey Mack Posted April 29, 2023 Share Posted April 29, 2023 fuse 41 in the fuse box under the hood by the steering column.. Do the reverse lights work, and it s just the indicator light? Manual tranny has a switch in the top for reverse. 2 wires going to it.. Quote Link to comment https://www.bigmacktrucks.com/topic/4070-reverse/#findComment-530344 Share on other sites More sharing options...
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