[rEvo] Petrel 2 controller intermittently shows 0.0/low PPO2 for all sensors

[mr_v]

the primary risk of using silicone lubes in the low pressure areas is cross-handling--lube up a large canister o-ring, then handle the high pressure DIN fitting without a thorough hand washing.

Yes, that's the reasoning I use.

 

[LFMarm]

Pins:
https://www.newark.com/molex/08-56-0110/contact-socket-22awg-crimp/dp/88H3600
Molex connectors: (I *think* these are the correct ones, but I haven't received mine yet to confirm)
https://www.newark.com/molex/22-01-3037/connector-rcpt-3pos-1row-2-54mm/dp/38C9145

I am about to build a few spare Molex connectors. To increase durability, I plan to use tinned stranded copper wire (22 AWG Stranded Wire Silicone Tinned Copper Wire).

Is it best to use tinned (Molex 0008500113) or gold plated (Molex 0008550131) connectors to be crimped to a tinned wire?

What about male-to-female connectors? Should it be gold male + gold female connector (Molex 1718561003 + Molex 0008550131), or tinned male + gold female (Molex 0022232031 + Molex 0008550131), or tinned male + tinned female (Molex 0022232031 + Molex 0008500113)?

I researched a bit on boating forums and it seems that once you start with tinned wires everything should be tinned to avoid gold-tin contact but wanted to check with this group before purchasing any parts.

Many thanks!

 

[mr_v]

@LFMarm ,

I have exactly the same wire in my Amazon shopping cart. Will use it with Gold plated connectors. I don't see a problem with tinned wires and gold connectors.

I am also thinking of sealing the connector tops with epoxy.

 

[stuartv]

@LFMarm What do you mean by "build a few spare Molex connectors"?

The molex connectors are plastic connectors and have pins inserted. The pins are attached to the ends of the wires coming out of either the O2 board or the monitor cable. Those pins are crimped and/or soldered onto the wires coming from the O2 board or cable, and then simply inserted into the molex connector.

So, what does it mean to build a spare molex connector?

I'm probably being super dense right, so apologies in advance if I'm missing something obvious.

Wait, do you mean you're going to build the connector with pins installed and wires coming out, so that you can cut off an existing connector and splice your wires from your "spare" onto the ends of the existing wires?

 

[LFMarm]

@LFMarm What do you mean by "build a few spare Molex connectors"?

The molex connectors are plastic connectors and have pins inserted. The pins are attached to the ends of the wires coming out of either the O2 board or the monitor cable. Those pins are crimped and/or soldered onto the wires coming from the O2 board or cable, and then simply inserted into the molex connector.

So, what does it mean to build a spare molex connector?

I'm probably being super dense right, so apologies in advance if I'm missing something obvious.

Wait, do you mean you're going to build the connector with pins installed and wires coming out, so that you can cut off an existing connector and splice your wires from your "spare" onto the ends of the existing wires?

I am building (1) molex harness connecting sensors to ChOptima head, (2) solenoid assembly, (3) pressure vessel for linearity test. I need to make molex wire-connectors connections for all 3. All parts have been selected but need to decide on coatings (tin vs gold).

 

[mr_v]

I am building (1) molex harness connecting sensors to ChOptima head, (2) solenoid assembly, (3) pressure vessel for linearity test. I need to make molex wire-connectors connections for all 3. All parts have been selected but need to decide on coatings (tin vs gold).

So, ideally, it is tin-to-tin, gold-to-gold.

Here is some useful info from Molex:

"Gold-to-tin is not recommended as it is well know that the reliability risk is greatly increased when these dissimilar metals are mated."

https://www.molex.com/en-us/blog/gold-or-tin-vs-gold-and-tin

However, I consider Molex tails to be disposable items, so tin-to-gold side effects won't be a problem. My original rEvo Molex piggy tail uses tinned wires and gold Molex pins.

 

[LFMarm]

Did some more digging:

• The male connectors of Analytical Industries PSR-11-39-MD Oxygen Sensor are gold plated
• The female connectors of the Dive Rite harness that attach to the O2 sensor are tin plated; the harness however has gold plated banana plugs going into the electronics head

Based on this:

• It looks like mixing tinned wire and gold plated connectors is done for this application (banana plugs on tinned wire)
• Gold female Molex connectors are a better connection to the sensors (according to the article above from Molex)

So I will go for gold plated connectors on both ends of my harness with a tinned wire in between.

 

[makar0n]

I am building (1) molex harness connecting sensors to ChOptima head, (2) solenoid assembly, (3) pressure vessel for linearity test. I need to make molex wire-connectors connections for all 3. All parts have been selected but need to decide on coatings (tin vs gold).

Do post pictures, I am very curious!

 

[LFMarm]

Do post pictures, I am very curious!

Actual build starts in a month. Here is the plan:

 

[makar0n]

Actual build starts in a month. Here is the plan:

View attachment 850290​

Thanks! I will keep an eye out for regular build updates