M1009 Resistor Bank

[tgtaylor64]

I have removed the resistor bank from the vehicle. What is the resistance suppose to be? What will it be if the resistors are bad? Truck had the bank by-passed. When I connected it and measured the voltage going to the glow plugs it started at ~10 VDC and then started climbing! I shut it off before I damaged the GPs and removed the bank. I would like to get a good one and go back to the OEM configuration.

 

[deuceaid]

is this the resistor for the glow plugs,,,, if it is removed then only send 12 volt power to the glow plugs.

 

[DriverSideImpact1008]

Honestly, I would keep it bypassed to the 12v system. Much less chance for problems.

If one glow plug burns out, the stock setup will increase the voltage to the rest of the glow plugs. Then steps it up again when the next plug burns out and so on and so on.

For example-- All 8 plugs get 10-12 volts normally. Then one plug dies and 7 GP's get 14 volts. Another 2 burn out...the remaining 5 GP's get 18 volts. More burn out, the remaining 2 get 23 volts. And all of the plugs swell and then you spend several hours pulling all the swollen plugs out of the engine, and god forbid a tip breaks off in the P.C. chamber...

All 8 of the GP's in my 1009 were swollen when I got it. 7 of the 8 had swollen too much and were stuck.

 

[mikelee]

 

[mistaken1]

I believe the testing procedure is in the TM. Should be roughly equal to the parallel resistance of all eight glow plugs.

TM 9-2320-289-20

Table 2-4. Electrical Troubleshooting (Con’t)

Disconnect batteries, pull out bracket and resistor assembly (see paragraph 4-44, REMOVAL, step 4), disconnect output (red wire) from relay, disconnect input (blue wire) from input to resistors. Connect positive lead of multimeter to blue wire; connect negative lead to red wire. Check resistance between resistors and ground.

Resistance should be 0.28 ohms.

Glow plugs should be 1-3 ohms (TM says check glow plug continuity semi-annually). Assuming 2 ohms per glow plug equals 0.25 ohms total resistance which is pretty close the 0.28 ohms of the firewall resistor.