I have a Fiat Hitachi FH150LC, early model. Today when I tried to start it i noticed a smell (that electronic box melting smell) and then some smoke coming from the right hand side of the seat, under the ignition switch. It turns out to be a relay. There is a cluster of 3 together, 2 metallic ones and a plastic one, down near the floor. I am going to have to source the relay from McSharry's here in Ireland but my immediate problem is 2 of the wires going into this relay have melted. Some genius in Italy decided it would be a good idea to have all the wires in the wiring loom the same colour, with a little number tagged to each end at the block connecter ( a little puzzle game for mechanics I guess). I don't know if they used this system on many machines. I am hoping somebody might be able to tell me where these 2 wires go to, as they go out of the bottom of the cab to Gawd knows where. There does seem to be some kind of system as 000 seems to be earth (ground). The wires I need to trace are 903 and 845. Thanks.
I traced the wires, one went back to the cut out switch on the diesel injector pump, the other went to the main solenoid switch ( small + terminal ) back at the batteries. I opened the relay box, there was a diode burned out in it. I managed to get the exact same diode on ebay so I was able to solder that in and repair this box. The fuel cut out switch is damaged too, it is shorting out, going straight to earth. I replaced the 2 wires and got a new cut out switch for the injector pump. I put an inline fuse at the main solenoid switch on the new wire, just in case something happened again. It is a good job I did as when I turned on the ignition switch, the fuse popped immediately. The main solenoid switch was damaged too. This is the switch that allows the battery earth lead to connect to ground. When I test the 2 small wires , check to see if they are going to ground, they are. I am going to replace the solenoid switch for a lever dead man switch. I want to be sure that the machine cannot go on fire when I am away from it. I obviously have another short circuit somewhere. I am pretty happy the wiring loom is not damaged. I had to take it all apart to trace the old damaged wires and put in new ones. At first I was blaming the diesel cut out switch for earthing out and frying the wires but now I am not so sure, possibly this was damaged by a surge of electricity?? I still have a wiring fault. I have ordered an FH200 workshop manual and a FH150 parts manual from Riland (member here), I have to wait for them to come from Ukraine though. I am hoping some of the electrical parts will be the same, ignition switch etc. When I have more information I can proceed further and hopefully sort this out. I am wondering if any of you have had any similar experiences, this seems like it might be a common enough electrical fault. Thanks.
I ordered the FH200 workshop manual because it seems the FH150 workshop manual cannot be got for love nor money....