Radiator fan....

[muleskinner]

Worked on Blue all day today. Switched out the thermostat with a new one and started it up. Runs for about 20 minutes and the engine starts heating up. It got to the point where we shut it off because the rad fan was still not coming on. We tried testing the relay, still good. So the only conclusion is a dead ground or shorted out wire somewhere. We cleaned the contacts and still nothing. The fan does work by the way.
Anyone else have any ideas as to why this fan will not come on before we start cutting wires to bypass the harness??

[SiliconSoul]

Guessing no codes - fuses all good?

[gergorian]

Are you sure that the sensor for the fan that is located in the thermostat housing is any good?

[bravekozak]

The temperature switch in the thermostat housing must ground. No teflon tape. It is straight thread and sels with an O-ring. Do a search. There are a lot of detailed explanations for this problem.

[muleskinner]

Tested all the grounds and hot wires, all seem ok. It did have a blown 20 amp fan fuse ..... Not sure if we did that or it was like that.

I have searched .... I guess I'm not typing in the right words. lol!

I will test drive it another day.

[muleskinner]

Ok, My search found if I have the key on & unplug the senser at the thermostat the fan will come on. Well I tried that on Blue & Squig and niether fan came on. So that means I have a broken wire somewhere or a corroded fan plug. Is that right??

I tried that on Shadow and it worked.

[crazyrog17]

Bad fuse, relay, wiring or fan motor

[crazyrog17]

Well the relay is set up fail-safe. It is energized when the key is in run but holds the contacts open. When the relay circuit is broken by the temp switch (breaks ground) it closes the fan circuit.

[muleskinner]

Bad fuse, relay, wiring or fan motor

Fuse is good, relay is good (tested), fan motor good (tested), & wiring is questionable. On further search it is probably a corroded fan plug.

[bravekozak]

Mule, just dip the entire plug into a glass of mild acid solution, then mild baking powder, then rinse, then dry. Like new again. No corrosion. Only use this procedure on brass contacts.
They used non-waterproof connectors for corner lights, starter motor, fan, horn and many other components that you can certainly bring to the good ol' service department.

Everyone should clean all of their connector terminals at least once every twenty years.

Use glasses to dip the entire connector in. The plastic connector and insulation will not be affected. Only the brass and copper. This beats poking a small file into the terminal to try and get some bare metal.

[denguy]

Should be able to check sensor to head continuity with an ohm meter.

[muleskinner]

Mule, just dip the entire plug into a glass of mild acid solution, then mild baking powder, then rinse, then dry. Like new again. No corrosion. Only use this procedure on brass contacts.
They used non-waterproof connectors for corner lights, starter motor, fan, horn and many other components that you can certainly bring to the good ol' service department.
Everyone should clean all of their connector terminals at least once every twenty years.

Use glasses to dip the entire connector in. The plastic connector and insulation will not be affected. Only the brass and copper. This beats poking a small file into the terminal to try and get some bare metal.

Cool, thanks for that info Kozak!! I will do that ...... I was wondering how to clean those contacts.

[AlaskaFestivaGuy]

BK:

So where do I buy my year 2034 DayTimer (or equivalent) appointment book so I can make a note to acid-clean all my Festy wires again?

[getnpsi]

I feel like blindly hosing off my whole engine bay with pickle juice!

[bravekozak]

BK:

So where do I buy my year 2034 DayTimer (or equivalent) appointment book so I can make a note to acid-clean all my Festy wires again?

If you don't want to schedule it in Outlook, then buy a 2017 Daytimer (or find an unused 2006 one at a garage sale) and just change the year to 2034. The days and months will all be identical.

Unfortunately, I have bad news for Festivas. I am predicting 2034 to be the year of Armaggedon. There are four blood moons + an annular eclipse in those two years. The total eclipse will be almost right over Mecca.