Cooling Fan Issue - Anyone have a wiring map?

[Mad Bull]

Just an update, guys, the fan is now working. The problem lie in the ignition switch, which was loose and not sending any juice to the wires going to the fan relay. We tightened it up, and the fan works great now.

Now it's time to get it on the road and see what ELSE is wrong, lol. By the way, is there a diagram for hoses out for the SVO? I think I've got a ton of vacuum leaks and some lines that I don't know where they go.

Whatever POs this car had were not nice to it and did things without any consideration to future owners of the car. The ignition switch, for example, looks like it was riveted to the steering column. When the time comes, I may have to replace the whole column just to replace the switch...

I've found a couple of other items I had questions about. Should I ask about them in this thread or start a new one?


Thanks for everyone's help!

[NavySVO]

[QUOTE=Mad Bull;156465]We tightened it up, and the fan works great now. [QUOTE]
Good deal

By the way, is there a diagram for hoses out for the SVO? I think I've got a ton of vacuum leaks and some lines that I don't know where they go.

See here, and here is a scanned copy from the 1985 MY EVTM

http://svoca.com/forum/showthread.php?p=156459#post156459

The ignition switch, for example, looks like it was riveted to the steering column.

that's the way it came

I've found a couple of other items I had questions about. Should I ask about them in this thread or start a new one?

If it is a new subject, start a new thread. People do sometimetimes use the SEARCH mode, and may not find their answer...

[Mad Bull]

Thanks a lot, NS. I will do that.

[DantePasqual]

So, If I removed the factory AC, do I need to jumper the AC dryer plug to get the fan to come on when I move the selector lever to AC? Right now, my fan isn't coming on at all except when I directly wire it. I think the wire is off the sending unit and will check when I have some time.

[Chuck]

Coolant Temperature Switch

I'm in the process of getting my coolant temperature switch working again. After several days of looking I finally found the little sucker. I managed to get a socket on it (1" deep well socket) and the darned thing sheared off. So I've still got the guts of the thing in the lower intake where I'm hoping I still have a coolant seal. I guess I can drive it but I'm heading over to Checker Auto to see if they've got a replacement. Ford wants $82.50 for the switch (1986, 2-wire) plus shipping from Cincinnati. The Ford part number E6SF-8B607-AA. It looks like O'Reilly has one numbered TFS27 for $23.99

[Chuck]

Fan Switch

Just checked OReilly's again and the TFS27 is now $36.99! AMazing what a page refresh can do. I also learned that OReilly's just bought Checker so I went there and they have one in stock but it is several miles away over in Glendale, AZ. I'll wait until tomorrow.

[SvoTy]

Just an update, guys, the fan is now working. The problem lie in the ignition switch, which was loose and not sending any juice to the wires going to the fan relay. We tightened it up, and the fan works great now.

Now it's time to get it on the road and see what ELSE is wrong, lol. By the way, is there a diagram for hoses out for the SVO? I think I've got a ton of vacuum leaks and some lines that I don't know where they go.

Whatever POs this car had were not nice to it and did things without any consideration to future owners of the car. The ignition switch, for example, looks like it was riveted to the steering column. When the time comes, I may have to replace the whole column just to replace the switch...

I've found a couple of other items I had questions about. Should I ask about them in this thread or start a new one?


Thanks for everyone's help!

You really need to think about changing out that ignition switch. There have been several fires over the years because of them.
It is not a hard job at all and you will probably be amazed how some stuff works better getting full current.

Ty

[runningpony98]

dont know if any of yall care but autozone sells the fan control module new. i believe its around $55

[RTStabler51]

Mike would your plan B also test to see if the motor is good?

[GAboySVO]

The ignition switch, for example, looks like it was riveted to the steering column. When the time comes, I may have to replace the whole column just to replace the switch...

That sounds like the original switch and screws. Use vise-grips to remove those screws and then replace with new serviceable type. As Ty says, you need to replace the ignition switch ASAP.

[BlueCASVO]

Don't forget about the fan motor!

Been reading this and the other post about cooling fan issues. One thing that seems to be overlooked is the cooling fan motor current draw. Though very likely not a cause of failure of the coolant temp sensor for the fan, if your fan conroller/TRW box is bad, it probably went bad because basically the fan motor is drawing too many amps to run. Over time, the electric motor that drives the fan will require more and more amps to start and run at the same speed. I ordered a new fan motor from Forced4 last summer for my 86, and it drew about 13 amps to run, in the shroud, with the fan blades on. The old fan motor (93k miles) drew close to 20 amps.

I do not know what the fan controller box is rated to, but if the stock fan is supposed to be around 13 amps the controller box is probably rated to 13.1 amps by design (built to be as inexpensive as possible). If your fan is drawing 20 amps, it's only a matter of time before the fan barbeques the controller box. If you put a new fan controller box in, it will work for awhile, but it also is probably not designed to handle the current draw of the aged fan, and its life expectancy will be significantly shortened.

Two other things I learned from rewiring my 85 was that the wire that carries the power to the fan is also probably rated to 13.1 amps, and the ignition switch can cause all kinds of electrical problems. The latter seems to have been covered, but IIRC the fan wire is a 12 gauge wire. The PO of my 85 had installed a dual fan unit from a tbird TC, and had both fans running on the same wire. Together they were drawing more than 20 amps, and the wire showed clear signs of excessive heat - crumbling insulation, and a much higher resistance level than what I expected. If the wire resistance is high, then it will also cause fan problems for both the fan and the controller box.

Hope this makes sense...

[Chuck]

The controller box actually contains two relays that do all of the current-heavy work. About the only thing that current can do a relay is pit the contacts. If the current is high enough to melt the contacts then you'll see smoke somewhere else. And, as we all know, if you let the smoke get out of something it usually stops working. The world runs on smoke.

[SvoTy]

Been reading this and the other post about cooling fan issues. One thing that seems to be overlooked is the cooling fan motor current draw. Though very likely not a cause of failure of the coolant temp sensor for the fan, if your fan conroller/TRW box is bad, it probably went bad because basically the fan motor is drawing too many amps to run. Over time, the electric motor that drives the fan will require more and more amps to start and run at the same speed. I ordered a new fan motor from Forced4 last summer for my 86, and it drew about 13 amps to run, in the shroud, with the fan blades on. The old fan motor (93k miles) drew close to 20 amps.

I do not know what the fan controller box is rated to, but if the stock fan is supposed to be around 13 amps the controller box is probably rated to 13.1 amps by design (built to be as inexpensive as possible). If your fan is drawing 20 amps, it's only a matter of time before the fan barbeques the controller box. If you put a new fan controller box in, it will work for awhile, but it also is probably not designed to handle the current draw of the aged fan, and its life expectancy will be significantly shortened.

Two other things I learned from rewiring my 85 was that the wire that carries the power to the fan is also probably rated to 13.1 amps, and the ignition switch can cause all kinds of electrical problems. The latter seems to have been covered, but IIRC the fan wire is a 12 gauge wire. The PO of my 85 had installed a dual fan unit from a tbird TC, and had both fans running on the same wire. Together they were drawing more than 20 amps, and the wire showed clear signs of excessive heat - crumbling insulation, and a much higher resistance level than what I expected. If the wire resistance is high, then it will also cause fan problems for both the fan and the controller box.

Hope this makes sense...

We found out that it was not the fan motors but actually the wire itself becoming high resistance over a period of time.
If you look at the wire from the connector back on both ends and it is a dark or coffee color you will want to cut it out and replace it.
Mine was actually getting so hot on the controller side that it would melt the circuit track off of the board.

Ty

[Meotchh]

The two relays should be capable of 30A each. Problems with the cooling fan relay module can also be traced back to poor wiring as Ty already pointed out.

[thomp22]

No cooling problems here!