Red light in MKII Carrier

[Robert Bergeron]

Here are pictures of my new cutoff and surrounding wires.Is the cutoff relay the blue «*thingy « to the left of the top picture ? What is the relay’s purpose and what is the description so i can order a new one please ? Many , many thanks .

[rob love]

That blue thingy might be a diode someone put in. It could be faulty. Testing it is easy enough...it is a one way valve for electricity. Disconnect the wire to the screw at the cutoff in order to isolate the diode. Put the leads of a multimeter set to ohms onto each end of the diode. You may or may not get continuity. Then switch the leads around. You may or may not get continuity. One way should give you continuity and the other will not. If you don't get continuity either way, then the diode is your problem. Don't be touching the bare ends of the leads when doing this test...you also have a certain measure of continuity.



You can also do this with a self powered testlight. The DC power should only go through one way.



If the diode is bad, you can toss it and run the wire straight across. I understand why someone put in the diode, although quite frankly, that is what the cutoff is for. Some of the replacement cutoffs are just that....a diode hidden under the cover. That blob on the diode may indicate it is bad, or it may just be bird poop or debris.


Edited to add: It may also be a capacitor, to replace the original filter unit. Either way, toss it and run the wire straight to ground. That blob on the side does not look kosher no matter which it is. You are out in the country....I doubt the lack of a filter will disturb anyones televisions or radios. You could run a short test lead with two alligator clips to see if that is your problem....just attach a lead to each side of the blue thing.


Edited one more time: Or is the blue thing just a blue butt connector? In that case it is likely just a red herring. It should have continuity through it. Pull on both wires going to it and make sure they are tight. If one comes out, you could replace it or you could use solder and heatshrink.

[Robert Bergeron]

No conductivity Rob . Off it goes . Will report back . Thanks !

[Robert Bergeron]

1 indicates 0 ohms according to the manual ( yes i had to read the manual .... ) . First time i use one of these . I have other skills but i am learning with the help of my friends from MLU !

[Robert Bergeron]

I think it is just a sleeve ( Blue plastic ) over a bad joint or connection sleeve . The wires must of come seperated with time . I started the engine , the red light is very bright . When i accelerate the rpm’s the red light fades considerably but it remains on but very faintly . Normal ?

[rob love]

Yep, it is just a plain old butt connector. Join the two wires together and see what happens.

Ohms is a measurement of resistance. One way to do a quick check is to touch the two terminals of the ohmeter together and look at your reading. That is a perfect circuit with little to no resistance. Now check them again on the item being tested. If you are testing a connection, it should be similar to what you got when you touched the two wires together. If you are testing something like an incandescant lightbulb, there will be a resistance....that's what causes it to glow. If there is no movement of the meter, then you have an open circuit or in the above two cases, a bad connection or a burnt out lightbulb.



You do not have to apologize or make excuses for not knowing this Bob. That is why electricians, furnace repair guys, and mechanics can charge $100 plus an hour for their services.

[Jordan Baker]

Originally Posted by Robert Bergeron

I started the engine , the red light is very bright . When i accelerate the rpm’s the red light fades considerably but it remains on but very faintly . Normal ?

This should mean the generator is putting out a charge. I believe in the manual there is a section in adjusting the 3rd brush to change the output of the generator.

Perhaps this is all it needed.

[rob love]

I was going to suggest that Jordan, and didn't catch that the light did dim somewhat. Good call.


That can be done on the vehicle, but if results are not there, then off to the rebuilders to get the brushes checked and cleaned.



I had an old tamper generator that I used to run a 125v crafstman impact gun off of. I used it to disassemble the 30 M151A2s I bought out in a field back in 87. Everytime I started it I would have to stick my screwdriver onto the segments to get it clean enough to excite the windings. In hindsight I should have took the time to open it and clean things up, but it really only took a few seconds my way.