M1008 resistor wiring ?s

[warwick]

After reading my TMs and searching here I think i found my glow plug problem. But I wanted to check with you all to see if i have it right.

First some back ground, I bought my M1008 from GL and have not changed any wiring under the hood. When I first brought the cucv home it was warm weather the truck would start rough and try to shake itself apart then smooth out as it warmed up. We had a cold spell a few weeks ago and it wouldn't start, wouldn't even try to catch. I pulled the glow plug card and pulled all the glow plug connections, then gave it a whiff of stating fluid. The truck fired right up and I drove it around the block then pulled it into the garage to trouble shoot the glow plugs.

After following the wire diagram and tracing the circuits I found the battery side of the resistor was changed by someone. The diagrams show a blue wire from the positive bar on fire wall to a fusible link to red wire to the passenger side of resistor. My truck has a white wire from neg post of back battery spliced to a blue wire to a fusible link to a red wire to the passenger side of resistor.[see pictures]

Questions

Any idea why they wired the resistor this way?

will the 12v input [from neg post and white wire] into the resistor drop to almost 0v? I checked voltage at glow plug connection with relay grounded and got 0.5v

Would it matter what post I use on the positive bar on fire wall? I plan on cutting the white wire at the splice. Attaching a connection and bolting it back to the bar. This should give 24v to resistor and 12v to glow plugs, correct?

Thanks

 

[mangus580]

What I would suggest... is buy a new set of glow plugs. Put them in. Connect the wire back the way it should. Monitor the voltage on the output side of the resistor.

when the glow plugs are on, it shouldnt be above about 12-13 volts. If it is, I guess move it back, there is something wrong with your resistors.

NOTE: This can only be done with a known set of good glow plugs!!

 

[CUCVFAN]

In your current config, you are only getting about 6V to the glow plugs, which will cause the symptoms you describe.

You could also try removing the wire on the other end of the resistor and hooking it directly to the 12V junction block on the firewall. This will give 12V to the plugs and it should start normally. The problem is, it is harder on the front battery when you leave it this way.