Sure wish there were instructions

[2ndwind]

I bought one of Mark's adjustable cooling thermostats. It comes with no installation instructions so I requested instructions by email and was only told to be sure to put it all the way through the radiator. I put the temperature probe just under the top tank because anywhere else would have bent a ton of fins. It only went in about 15% and it worked adequately but was sticking out 85% so I pushed with some force and it went in until it touched the body rail in front of the radiator. Great!

Not great. Now my 1 yr. old radiator has a serious leak where the probe is. Sure wish I'd had some instructions. I searched this forum several times for someone who installed it without problems. I looked under adjustable cooling switch, cooling switch, adjustable switch, adjustable installation.

I only did this because the last two stock coolant thermostat switches during idle allowed the temperature to rise too much (220 degrees) before coming on and couldn't pull the temperature down unless I could get the car moving. I figured if the fan would come on sooner, it would work out. Now I know why so many people have extra fan override switches inside the cockpit. I know the stock setup is SUPPOSED TO WORK but alas mine does not.

When driving around the temperature almost never goes above about 195. The head has about 800 miles after rebuild. Newer radiator as mentioned above. I am far from a newbie around old cars but this has me about to throw in the towel on fiats and go buy an old American car or unrusted 280Z.

[So Cal Mark]

I don't know what additional instructions you need. It's so straightforward in it's simplicity. Your old switch has two wires. The new switch has 2 wires. You connect the 2 wires. The sensing bulb has to be inserted fully into the heat source. If the bulb isn't inserted fully, then you've left it exposed to cooler air and it won't work accurately.

You mentioned how previously the fan wouldn't bring the temperature down. That indicates a lack of circulation, usually a restricted radiator.

[v6spider]

Sounds like you need a new radiator.. Restricted flow would definitely cause the higher temps. Fan should only come when idling for long periods of time..

Cheers!
Rob

[2ndwind]

Wiring was no problem. It operated fine but most of the tube was still sticking out. So i shoved it in farther. Today I removed the radiator and looked at the insertion point. As I said, I put it in just below the top tank. Because it did not go in very far I shoved it in farther till it came through the radiator touching the cross rail of the body (don't know the correct name). Because the radiator tubes are purposely offset, it appears that action tore one of the vertical tube's solder point at the top tank causing the leak.

What is the actual location you guys insert the bulb? Do you insert it several inches below the tank, bending a bunch of cooling fins, or just not as far through the radiator (like I did), just under the top tank?

[RRoller123]

Typically the temp is measured near the bottom of the radiator.

Pete

[KevAndAndi]

FYI, at least one of our vendors sells a non-adjustable thermo switch that activates the fan at a lower temperature. Sounds like you should address the disease rather than just the symptom, though.

[v6spider]

Just below the upper tank is the correct insertion point.. However, you do have to be careful inserting it so as not to damage the cooling tubes. Flex a lite has the same setup and I have used them before.. Very accurate control too.. But from what you are describing it definitely sounds like a clogged radiator. It could also be that the tube you damaged inserting the bulb was starting to rot causing it be easily damaged but without seeing the radiator it's hard to determine at this point..

Rob

[2ndwind]

Ok I have cooled off. I apologize that I was steamed about this issue. Puns Intended. The reason I didn't suspect the radiator was that I thought it was a new radiator core from about three years ago. I took it to the radiator shop for repair, he fixed the hole I put in the tube but testing under pressure revealed a leak at the bottom tank, fixed that and another leak developed at which point he offered to re-core it for $500.

He went back to his records which showed 6 YEARS AGO I had the radiator rodded and repaired in their shop, no core replaced (Just found the receipt-yep they are right). Tail between legs.

So I have a deteriorated, at-least-once repaired, leaky 34 year old radiator. Probably time for a new one.

Thanks for your patience and reminding me these cars are pretty cool.
Hothead soon to be cooler than ever.
Steve