FMTV Anti Theft starter relocation

[BRob18E]

I wanted to contribute to the community and share a few pictures. I posted a threat about some relays I had getting hot, and then after troubleshooting and replacing a few relays. (thanks everyone that helped on that post). After everything was said and done, I didn't want to dig into the starter relay not working since everything else on the truck works perfect, so I bypassed it. My son always worries about our vehicles getting stolen so I used this problem and made a fix for the theft device. (yes anyone that knows these trucks that spends a little time looking around may find the bypass, but I thought I would share just in case someone liked the idea.

 

[19Detail]

Nicely done. You could go one step further and label the switch something stupid/unrelated (like "Work Light" or "Winch Power") so it doesn't even cross their mind. Also, do you have a source for the covered toggle you used? I am looking for that exact switch.

 

[BRob18E]

I do not. it was inside my truck when I purchased it. Not this one buy my other M1083. I am assuming those toggles are probably easy to locate due to being used on other applications, even in the civilian world. I can try to find a link to post.

 

[BRob18E]

http://www.partdeal.com/wiring-elec...54HObidrk-qAnDwTFnwKiic1vNSL9RRhoCQL0QAvD_BwE

 

[19Detail]

Thanks, I have found them on-line but yours looked like it was already in a snap in blank that was the size of the dash cut out.

 

[coachgeo]

how did this bypass your previous issue(s) as well? AKA.... a relay is like a fuse...... if you just bypassed the fuse thru a switch are you not opening the door to allowing an electrical problem continue with no safety net between (the relay)

 

[wheelspinner]

how did this bypass your previous issue(s) as well? AKA.... a relay is like a fuse...... if you just bypassed the fuse thru a switch are you not opening the door to allowing an electrical problem continue with no safety net between (the relay)

A relay is nothing like a fuse. It is a way for a low-power signal to.transfer higher current. My concern would be the sustained higher current through a switch it it's not designed for the current load. If the switch is designed for the current then it's fine. The circuit is fused before the power is supplied to the relay socket.

 

[BRob18E]

As for the switch, I just pulled one of the blanks out that was on the box already and drilled a hole in it to match the switch. If you look at the pictures you can see a few more blanks off to the right.

As for the question about the current. How I am understanding this is. On one of my other threads (https://www.steelsoldiers.com/showt...ker-Lamp-Relay-Gets-Hot-when-I-turn-on-lights) when I asked for help troubleshooting a relay what was getting hot, and asked for advice about my starter button not working, but when I opened up the relay and push the relay over to make contact, the starter works. The user NTD told me it was more than likely a relay or fuse in my VIM. I actually opened up the VIM and did continuity test on the fuses but at the point I was going to pull the relays, the idea popped into my head to install the switch.

So, "I THINK" there is a signal that comes from the start button when pushed. That sends a signal to the VIM and the VIM verifies or makes sure that it is OK to start the motor. At which time the VIM allows the signal to go to the starter relay. Once the relay receives the signal, the relay makes contact on the two contacts in which I have put my switch on. Once those two contacts (my switch) (Low amperage at this point still) makes contact it sends a signal to the starter solenoid which in turn makes contact of the high amperage wires that sends power to the starter. AT LEAST I HOPE ANYWAY...LOL..LOL... Sounds good in theory right...lol...If the fukker burns down, I'll sell the crane and tires and update the thread..

So far it's working as it should. I am still waiting for a big lot of fuses. My equipment trailer I just got in, the lights weren't working. So I got back in the panel and pulled a few breakers and moved them around and got it working. My crane didn't work, but trailer lights did. So once I replace all the fuses and relays, I think it will be a good refresher for preventative maintenance on the electronics and all will be fine. I think someone at the yard or a worker at the motor pool took the rear lights off my trailer. Everything on the trailer is LED lights except the rear lights and they were not hooked up. So a quick $200 for someone. But the lights they replaced them with just needed new bulbs and hooked back up properly and they work great now. just not LED.

 

[Ronmar]

Power for the start circuit comes thru the vim neutral start relay to the coil of K1(K1-86). You should have 24V at pin 86 with the sw on. If not the problem is in the VIM or wiring or neutral start authorization from the trans controller that controls the VIM relay.

The other side of K1’s coil(85) goes to K24-30(crank lockout) pin 30 to 87 are normally open. From K24-87 it goes to the starter button and on to ground to complete the circuit that energizes K1

K24 is controlled by the oil pressure sw. When you turn on the main sw K24, K11 and the oil and stop lights in the panel should be energize by the oil pressure sw below 15 PSI. K24 being energized allows a circuit to the start button so K1 should energize and the engine should crank when you push the button. When 15 PSI is reached K24 and K11 de-energize which keeps you from engaging the starter when the engine is running(K24) and brings the alternator online after the engine is running(K11). There is a little latching circuit that keeps K24 energized as long as the starter button is depressed to keep the starter from dropping out during those long winter cranks when you might get enough oil pressure to open the oil pressure switch while still cranking.

Brob18e your start issue may be a problem with K24 not energizing when you close the main switch... Measuring for 24V at K1-86 will tell you which direction to look though...

 

[BRob18E]

Thank you. I have all new relays coming. For anyone else's knowledge. There is 10 of the 12v 4 pin. (#1 on the panel cover). There are 5 24v 4 pin. (#2). There are 5 12v 5 pin. (#3). And there are 6 24v 5 pin. (#4 on the panel cover). I'm going to replace all of them and keep the old ones for spares. I have been playing musical relays to make sure everything works, so I'll put a new relay in K24 and then replace the starter relay to see if it fixes the issue. Do you see any issues with going back to the way it is even if everything works correctly with the new relays?

 

[Ronmar]

Thank you. I have all new relays coming. For anyone else's knowledge. There is 10 of the 12v 4 pin. (#1 on the panel cover). There are 5 24v 4 pin. (#2). There are 5 12v 5 pin. (#3). And there are 6 24v 5 pin. (#4 on the panel cover). I'm going to replace all of them and keep the old ones for spares. I have been playing musical relays to make sure everything works, so I'll put a new relay in K24 and then replace the starter relay to see if it fixes the issue. Do you see any issues with going back to the way it is even if everything works correctly with the new relays?

As long as the switch contacts are rated to the same level as the relay contacts of K1, no I see no issue with it...

You could have simplified things a little. You only needed to get 5pin relays as they will work in both the 4 and 5 pin locations...