Inside the Otterstat

[DMC-Ron]

I just replaced my nearly new Otterstat. I installed it last fall and I'm not sure it ever worked but it certainly wasn't working on my recent outing (had to turn on the AC to get the fans on). I kicked myself for not testing it before installing. Luckily, I had purchased two and had a spare. This time I tested before I installed. My original Otterstat failed, likely because it had a crack in the sensor casing. Being a curious nerd, I decided to take the original one apart and see what was inside:

Here is the original with the crack:
66047

Here's what's inside:
66048

And here's a closeup of the sensing element:
66049

So before installing the new Otterstat:
66050

I set up a test to heat it up and verify it would work:
66051

I'm guessing others have done the same. Here are my results:
66052

Now to my question. There is a comment on the DGo website where it says: It is recommended to install this using 2 zip ties on the outer edges (rather than a clip thru the middle) to minimize the pressure on the internal workings
66046

My retaining clip is pretty tight. Could this have caused the failure of the first replacement? Is there any concern using the original retaining clip?

Ron

[dmc4087]

Highly recommend this product from DGO - fit and forget really
https://www.deloreango.com/uk/stainless-water-pipe-with-screw-in-otterstat.html

The original otterstat is a bit mickey mouse

[DMC-Ron]

Highly recommend this product from DGO - fit and forget really
https://www.deloreango.com/uk/stainless-water-pipe-with-screw-in-otterstat.html

The original otterstat is a bit mickey mouse

Granted. That does look like a great improvement. Plus, I like that it operates at slightly lower temperatures. But, it looks like you need to drain the system to install. Worth considering when I schedule a coolant changeout.

Ron

[Nate88]

I purchased the adjustable fan switch from DeLorean Parts Northwest: https://www.delorean-parts.com/product/wings-b-cool-adjustable-fan-switch/

While I haven't installed it yet due to having to drain and open the system up (and I haven't really had a reason to yet), it was highly recommended from others in the community. Could be another option.

[Josh]

The zip ties are a Band-Aid fix, but i will agree the original otterstat setup is far from ideal.
I really like the testing apparatus. The Dgo screw in otterstat is the way to go if you are concerned.

I would see some opportunity in making an electronic work around to the otterstat, I know you have the abilities... :D

[DMCMW Dave]

In my experience the biggest cause of failure (other than that case cracking) is dropping it. We learned in the shop that if the tech drops it, right into the bin and get another one. Even a 3 foot drop onto the floor. Handle them like glass.

[David T]

In my experience the biggest cause of failure (other than that case cracking) is dropping it. We learned in the shop that if the tech drops it, right into the bin and get another one. Even a 3 foot drop onto the floor. Handle them like glass.

And NEVER use silicone on that orange gasket seal. It will eventually cause the seal to split. Use anti-freeze to lubricate it before you install the "O" switch. I also always wondered why they put it where they did. It usually screws into the tank on the radiator on most cars. As for adjustment and setting, it is a critical range because it must work in relationship to the thermostat. The cooling fan circuit is not supposed to run continuously, it must stop and start. As for the metal clip, very often it is missing so you use a strap tie (I only use 1). Never had a problem with the metal clip. Just watch, the "O" switch terminals have a plastic insulator on each one so the clip doesn't short them out.

[FABombjoy]

I would see some opportunity in making an electronic work around to the otterstat, I know you have the abilities... :D
-Temp gauge sender
-Fan switch
-Lambda switch
-Thermo time switch
-Idle system switch
-Special guest star vacuum switch
It almost sounds like crazy nonsense when you type them all out.

[David T]

-Temp gauge sender
-Fan switch
-Lambda switch
-Thermo time switch
-Idle system switch
-Special guest star vacuum switch
It almost sounds like crazy nonsense when you type them all out.

With all of these things becoming "electronic" it might be time to integrate all of the functions into a controller.

[DMCMW Dave]

The cooling fan circuit is not supposed to run continuously, it must stop and start. .

You keep saying that, without an explanation or other proof, and I've never understood why. So I'll call BS on this theory.

I rewired mine decades ago (credit to Darryl Tinnerstadt) so that the fans would run 100% of the time with the A/C turned on. They do not cycle with the compressor. Never had an issue. The only drawback to running it all the time might be battery drawdown at idle due to the underpowered alternator, which most people have replaced by now anyway. The power surge of turning the fans off and on is a lot more trouble and wear and tear than just having them running. It won't overcool the engine (that is what the thermostat is for). It's no different than the air flow going through the radiator at 50 mph. Which doesn't seem to hurt anything.

[Josh]

You keep saying that, without an explanation or other proof, and I've never understood why. So I'll call BS on this theory.

I rewired mine decades ago (credit to Darryl Tinnerstadt) so that the fans would run 100% of the time with the A/C turned on. They do not cycle with the compressor. Never had an issue. The only drawback to running it all the time might be battery drawdown at idle due to the underpowered alternator, which most people have replaced by now anyway. The power surge of turning the fans off and on is a lot more trouble and wear and tear than just having them running. It won't overcool the engine (that is what the thermostat is for). It's no different than the air flow going through the radiator at 50 mph. Which doesn't seem to hurt anything.

Dave, please refer to the workshop manual. You will note from your reading that the fans must cycle. The reason for this is because that is the way they are. You are best to reverse your wiring to a stock configuration because that is the best. Stock is best, Lucas is best, service manual is best. While flipping through the workshop manual you may also notive your differential has been installed backwards for decades. Take it out and correct that too.

[DMCMW Dave]

Dave, please refer to the workshop manual. You will note from your reading that the fans must cycle. The reason for this is because that is the way they are. You are best to reverse your wiring to a stock configuration because that is the best. Stock is best, Lucas is best, service manual is best. While flipping through the workshop manual you may also notive your differential has been installed backwards for decades. Take it out and correct that too.

Says the smartass LS guy. . . . . . :)

[Ron]

Says the smartass LS guy. . . . . . :)
I think he may be like that because he doesn't want anyone around, eyeing the 14M fan switch on his LS....:deviltail: