Hope someone can shed some light on this one. I swapped out the ZF transmission with a rebuilt unit. The backhoe would start and run fine before hand and now with the rebuilt transmission i have a no crank situation. The F7 fuse blows when going to the start position with the key. I can manually jump the starter and it cranks fine, no power to the fuel shut off solenoid. The F7 fuse is stated as Fuel/Srt aid/Back up alarm, i have disconnected both the back up alarm and the fuel shut off solenoid and still blows the fuse. This particular unit doesn't appear to have the start aid option. If anyone can help with a wiring schematic or has encountered this problem i would really appreciate the input. Thanks!
Welcome to HEF Stevie ! Need the machine serial number please. Did a wire get pinched on the repair?
T0310SG905444 Cannot find anything pinched, clean install. The temp sender at the top of the trans wiring connector was broken before we removed the trans thats the only thing i have found
Correct, the only things on the F7 fuse are the backup alarm, fuel shutoff solenoid, and start aid, if equipped. Your serial number indicates it was built with the start aid. Look at the right front end by the radiator's expansion bottle. That is where the start aid solenoid would be mounted. If unplugging that does not stop the fuse blowing, then there is a wiring issue somewhere between that fuse and those components. Also, the backup alarm works through a relay (K4). Try unplugging that. It would be in the fuse box, relay all the way to the right, closest to you.
Must be solar flares acting up. I'm seeing a lot of start issues in the backhoe forum. Can you confirm the fuse blows when going to the ON position? That specific circuit will be energized before you get to START. If it's like the SE model, which it sounds similar there will be two power leads off the fuse. One going to the start aid switch and one to the backup relay. The relay and the switch are within a foot of each other in the panel so it's unlikely you're rubbing on anything in the panel itself. Remove the relay like mg suggested to eliminate this. The start aid switch has a power source going into and out of the switch which goes to the fuel injector pump shut-off. The shutoff wire goes under the machine through a harness connector around the back of the engine to the pump. I'm guessing you're rubbing somewhere on the backside of the engine, but the factory sheathing is pretty tough. I'm interested to see what you find. I'm chasing an intermittent loss of 12V to my pump shutoff. I'm not sure if this is how your SG is, but this is how my SE is wired. Hopefully it doesn't confuse the matter.
I appreciate the input. I found a 2 spade connector beside the radiator exp bottle that has been tied up not connecting to anything ( assuming it was removed at some point) pulled the B/U alarm relay (K4) and still blows the fuse. A big question for me is if the F7 fuse is blown will that cause the engine to not crank? i have a feeling i may be chasing 2 issues nut without a schematic i am in the dark on this one. Again i really appreciate the info!
It doesn't make a whole lot of sense.. just swapped the trans and now this no crank issue. Can only assume the F7 fuse has blown since i did the swap as i didn't have any issue prior (other than the guy i am doing this for sent it to me with no fuel in the tank, LOL) i responded back to MG2361 regarding the start aid and b/u alarm relay. If its a rubbed or broken wire that's fine but if the F7 fuse is blown does that create a No Crank scenario? i appreciate the help. Still trying to get my hands on a schematic, would help a bunch. Thanks again! Yes it does blow the fuse when the key is turned to the ON position.
I believe you have 2 issues. As far as F7, check where the harness goes over the top of the transmission. They have a history of rubbing through on top of the control valve on one of the control valves cover bolts. I PM'd you.