TK RD-II SR intermittent operation

[trammd]

Darn I cant uploada photo, limit of 100kb!

[seanf]

Upload it to somewhere like Flickr.com and then post a link.

[trammd]

low res 2R (1).jpg

low res1 (1).jpg

See the above photos. The fusible link only had the one large guage battery feed (8 Gauge?) mounted to the left stud side of it. (It is removed in the photo as per my testing- you can see the white wire taped out of the way in the second photo.)
There is an access cover under the RD-II... maybe the feed wires (alt., etc are located on the back of the FLW stud right side. (not visible from the access door side)?

[seanf]

Yer looks like its hidden behind.

A link to a better manual, easier to read wiring diagrams and schematics at the end of it. Zoomable and rotatable.
https://www.ctrserv.com:8443/phprunn...ing/rdiisr.pdf

[trammd]

back of FLW.jpg
lower panel.jpg

Okay see photos,
There are 3 wires attached to the opposite side of the FLW. Looks like the two #2 wire and a smaller one. (not sure what the smaller one does)
They look to be mounted well and intact. But I will need to remove the Bottom panel of the reefer to get better access for full inspection. (I can currently only view them with an inspection mirror.)

The Unit runs for now with all three of those wires out of the picture. (jumper P5 from battery)

Here's a thought, What if I move my battery jumper to the left post of the FLW and re-connect my two #2 wires to the P5 terminal on the board for a test?
Would this rule out the wires that run from the FLW to the Relay board/Alternator if the unit runs normaly?
and at the same time condemn the main power feed to the FLW ?
thoughts?

It would be nice to rule out those wires/connections as removing that lower panel does not look fun!

[seanf]

back of FLW.jpg
lower panel.jpg

Okay see photos,
There are 3 wires attached to the opposite side of the FLW. Looks like the two #2 wire and a smaller one. (not sure what the smaller one does)
They look to be mounted well and intact. But I will need to remove the Bottom panel of the reefer to get better access for full inspection. (I can currently only view them with an inspection mirror.)

The Unit runs for now with all three of those wires out of the picture. (jumper P5 from battery)

Here's a thought, What if I move my battery jumper to the left post of the FLW and re-connect my two #2 wires to the P5 terminal on the board for a test?
I think if you had been getting battery voltage at both side of FLW on the previous tests, then doing this youd probably see the voltage drop problem again. But it could restore your stability on the alternator voltage.

Would this rule out the wires that run from the FLW to the Relay board/Alternator if the unit runs normaly?
and at the same time condemn the main power feed to the FLW ?
Yes it would condemn the battery to FLW wire.

thoughts?
From your previous test results, I would guess the problem is with the two #2 wires from the back of the FLW to the P5 on the board.

It would be nice to rule out those wires/connections as removing that lower panel does not look fun!

See the other blue text first.

You could do continuity checks on the wires to see what is going where. I'm guessing the small wire is the alternator sense wire.

I would say, do the tests you think you need to do. Theres probably something to gain from it, even if its only knowledge.

I'm gona guess, your probably going to get to the point where you end up running new #2 wires from the back of the FLW to P5 on the board, or find damage or something loose.

[trammd]

Thanks, Do you happen to know the removal procedure for that bottom panel? I can't find the information anywhere online. I am not sure if the front grille needs removal?

[seanf]

Thanks, Do you happen to know the removal procedure for that bottom panel? I can't find the information anywhere online. I am not sure if the front grille needs removal?

Dont know, sorry.

[trammd]

Okay thanks, I think I am gonna jumper direct from battery to feed side of the FLW just to confirm the faulty #2 wires. If the odd chance that the unit functions then at least I am only dealing with the battery wire. Easy check to do before I tear into this thing further. Thanks again for all of your help with this!

[trammd]

Here's a thought, What if I move my battery jumper to the left post of the FLW and re-connect my two #2 wires to the P5 terminal on the board for a test?

Well, this test was sucessful, so far. Unit starts and runs good with main battery feed wire jumpered.

I think if you had been getting battery voltage at both side of FLW on the previous tests, then doing this youd probably see the voltage drop problem again. But it could restore your stability on the alternator voltage.

Alternator voltage now good, regulated at 14.0 Volts while running.

Would this rule out the wires that run from the FLW to the Relay board/Alternator if the unit runs normaly?
and at the same time condemn the main power feed to the FLW ?
Yes it would condemn the battery to FLW wire.

Its looking like the main power feed from battery is the suspect wire as of right now,

I guess the next check is to hook up the factory battery feed wire again and confirm the voltage drop issue....

[seanf]

If the factory battery feed wire also works, then try giving the wiring harness the #2 wires run through a shake/wiggle.

[trammd]

SO, Im Back!

the craziness continues....
As I was trying to rule out which parts of my harness needed replacing today the unit started shutting down when I jiggled the thermoguard switch harness. So i immediatly jumpered my P5 terminal again eliminating the two #2 wires and Sense wires from alternator through the FLW. (Board powered direct from battery)

Now every time I manipulate or wiggle/twist the switch harness plug the unit will shut down. (code 63) when I clear the code I can restart and repeat this quite easily. (Does this with both new switches)
When I push/pull the actual harness the plug the unit will shut down, (and I can see and hear feedback at the board with the the relays and led lights clicking and flashing as I wiggle the harness plug. the wires to the board from the switch harness look intact and wiggling or moving them does nothing. Only when i Moved the actual switch harness plug do I get the shut down.

Unit runs great as long as I am not messing with the switch!

At first I thought it was a bad CHP (ground) terminal at the switch that was causing this but it seems to also stop the unit when I pull the other wires independantly.
I JUST got it to shut down again by pulling gently on the switch wire labeled CHP (ground)
Do you think I should replace the harness plug with new individual crimped female spade terminals??
What do you think?
Thanks!

[seanf]

Id probably first de-pin the wires from the plug, check them for damage or corrosion. Then give the spade terminals a little squeeze so they fit tight to the male end on the switch.

After that probably replace the wire or try and find the damage/corrosion.

[trammd]

So definitely tied to the #2 wire at the back of the switch! moving the 2 wire around is causing the power to drop out and killing the unit. I assume this switch power feed (2) originaly comes from the FLW through the #2 wires to P5?
Currently powering P5 direct to battery. so does this mean the power drop out is in the board circuitry? (from P5 to the swicth harness receptacle at the board?)

Why would wiggling the #2 lead at the switch cause this?

[trammd]

should I first try to de-pin #2 at the switch end of the harness plug then use my 3A jumper wire to power #2 direct to battery?
Thoughts?

[trammd]

I just replaced the female spade terminal #2 at the switch side harness plug. same symptoms.

[seanf]

Take some voltage measurement, to try and narrow down where the problem is.

With one of your meters leads always connected to the battery negative post and the switch "on", check what voltage you get at:

- P5 terminal on the board.
- P7 terminal on the board.
- P1 terminal on the board.

On the switch harness plug, that plugs into the board. Back probe the terminals:
- CHP
- PL1
- 2A
- 2
- 2N

On the switch harness plug, that plugs onto the switch itself, test the terminals:
- CHP
- PL1
- 2A
- 2
- 2N

Wiggle the wires to create the fault and keep an eye on the readings.

[trammd]

So just the switch "ON" when taking the readings? Or should the reefer be running also?

[seanf]

I would try with just the switch "on" first and see what you find. If you get nothing, then run it aswell.

[trammd]

Okay, Thanks

[trammd]

Since the problem occurs when specifically manipulating the switch harness plug I decided to cut off the factory plug and replace it with individual female spades that are tight fitting and no corrosion at the switch. Also ohm'd out all the wires in the switch harness from the board plug to the switch. Cleaned the board terminal and harness plug with De Oxit and checked pins etc. all looked good.
Plugged everything in and fired up the unit. Runs good and I can't get the unit to die by wiggling the switch or spade connections were as yesterday it died everytime when messing with that switch plug.
IMG_20241010_110651517_HDR.jpgIMG_20241010_110046209_HDR.jpgIMG_20241010_105900503_HDR.jpg

[seanf]

good, hopefully no more problems come up.