Need some help with head electrical gremlin...
#1
Need some help with head electrical gremlin...
I am having an issue with the circuit on my macerator.
Things I know that are good:
Switch is good. (Checked with DVM and the water pump still works.)
Macerator motor is good. (Checked by hooking up to jump box.)
Spare/2nd macerator motor is good. (Checked by hooking up to jump box.)
Ground is good. (Ohmed out to ground behind dash just fine.)
+/Hot side of circuit is good. (Checked with DVM to circuit's ground as well as a different ground.)
When I remove the macerator from the circuit, and only use the DVM to check voltage across the circuit; the DVM reads 12.25VDC when the switch is pushed. (Exactly as it should.)
When I use the + side of the macerator circuit and go to a new/separate ground with the DVM only, the DVM reads 12.25VDC when the switch is pushed. (Exaclty as it should.)
When I hook the macerator into the circuit normally, AND also try to read VDC across the same circuit, the DVM reads .003VDC.
The macerator does not flinch. (Have checked with two macerators.)
When I hook the macerator normally, AND also try to read the
VDC from the + of the circuit, across to a ground lug behind the dash, the DVM reads .003VDC. The macerator does not flinch. (Have checked with two macerators.)
I don't get it. This pretty much defies all EP logic.
I know the switch is good. I know there is no inline cicruit breaker or fuse, and besides, the circuit reads 12.25VDC when no macerator is plugged in. BOTH macetors work fine when hot wired to a 12VDC jump box.
Help!?!?
What am I missing? I will try a new ground tomorrow, as I got too frustrated tonight. Anything else?
Thanks in advance. NO peanut gallery comments please. I am trying to get this fixed tomorrow to head to a Poker Run, and the boat will be at the lake through Memorial Day.
Things I know that are good:
Switch is good. (Checked with DVM and the water pump still works.)
Macerator motor is good. (Checked by hooking up to jump box.)
Spare/2nd macerator motor is good. (Checked by hooking up to jump box.)
Ground is good. (Ohmed out to ground behind dash just fine.)
+/Hot side of circuit is good. (Checked with DVM to circuit's ground as well as a different ground.)
When I remove the macerator from the circuit, and only use the DVM to check voltage across the circuit; the DVM reads 12.25VDC when the switch is pushed. (Exactly as it should.)
When I use the + side of the macerator circuit and go to a new/separate ground with the DVM only, the DVM reads 12.25VDC when the switch is pushed. (Exaclty as it should.)
When I hook the macerator into the circuit normally, AND also try to read VDC across the same circuit, the DVM reads .003VDC.
The macerator does not flinch. (Have checked with two macerators.)
When I hook the macerator normally, AND also try to read the
VDC from the + of the circuit, across to a ground lug behind the dash, the DVM reads .003VDC. The macerator does not flinch. (Have checked with two macerators.)
I don't get it. This pretty much defies all EP logic.
I know the switch is good. I know there is no inline cicruit breaker or fuse, and besides, the circuit reads 12.25VDC when no macerator is plugged in. BOTH macetors work fine when hot wired to a 12VDC jump box.
Help!?!?
What am I missing? I will try a new ground tomorrow, as I got too frustrated tonight. Anything else?
Thanks in advance. NO peanut gallery comments please. I am trying to get this fixed tomorrow to head to a Poker Run, and the boat will be at the lake through Memorial Day.
#2
Charter Member #232
Charter Member
You say you are testing voltage. You may be getting voltage but NOT amps. To make that motor work you need AMPS and volts.
For example: The glowplug relay in my truck was passing voltage but the truck would not start. It could not pass enough current to heat up the glow plugs. Replaced the relay and whamo it worked perfectly from that point on.
My guess is that you have a switch that is not passing current or a wire that is partially corroded/broken. Look down that road and find your culprit
Jon
For example: The glowplug relay in my truck was passing voltage but the truck would not start. It could not pass enough current to heat up the glow plugs. Replaced the relay and whamo it worked perfectly from that point on.
My guess is that you have a switch that is not passing current or a wire that is partially corroded/broken. Look down that road and find your culprit
Jon
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#3
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Hey brian give me a call it sounds like your circuit is not able to carry the load. It's hard to explain but you could have some corrosion or broken strans or copperin the wiring. Call me and I can tell you how to check it. Mist likely it's corrosion in the wiring under the protective sheild. We see it all the time in cars.
Terry
434 531 8169
Terry
434 531 8169
#4
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Hey brian give me a call it sounds like your circuit is not able to carry the load. It's hard to explain but you could have some corrosion or broken strans or copperin the wiring. Call me and I can tell you how to check it. Mist likely it's corrosion in the wiring under the protective sheild. We see it all the time in cars.
Terry
434 531 8169
Terry
434 531 8169
#5
Of all the things that got wet, the head was not one of them.
Thanks everyone. I am going to do some more digging. Its not too hard to replace the wiring from the switch to the macerator and then to ground to test. I think I will try this first.
#6
3 hours later. I found the problem. The power feeder wire had issues.
Some of the wiring was not factory. I don't know who could have done it, but I know I did not, and Todd did not. There was a butt connector that in the feeder wire from the dash to the switch. The connector was not able to be seen. I only found it by feeling my way down the entire wire with my arm buried up to my elbow. This connector sat in a tray that probably got wet once or twice. The butt connector was full of corrosion. There is/was about 18" of extra wire on that circuit too. Again, VERY strange.
Now I have to go put it all back together.
Thanks everyone.
Some of the wiring was not factory. I don't know who could have done it, but I know I did not, and Todd did not. There was a butt connector that in the feeder wire from the dash to the switch. The connector was not able to be seen. I only found it by feeling my way down the entire wire with my arm buried up to my elbow. This connector sat in a tray that probably got wet once or twice. The butt connector was full of corrosion. There is/was about 18" of extra wire on that circuit too. Again, VERY strange.
Now I have to go put it all back together.
Thanks everyone.