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Discussion Starter #1
I plan on bypassing the sender on the Alfetta GT's radiator with a questionable rocker switch. Questionable in that it is very tiny (about an inch long) and is for a 120V lamp. There is writing all over the base, but doubt if it would pertain to running a 12V DC motor.

It's already installed in a convenient place to switch off (keeps running with engine off) and on. My concern is that it will be just fine until I get to a particular mile long black hole [that I'll be (hopefully) passing through this Sunday] and the switch goes kaplooy and red light for the temp gauge gets even redder. If I install a toggle switch it has to dangle down since I'm not going to install it permanently.

Will I be okay?

Should you be bored stiff, this is what I've been dealing with:

Not long ago the radiator fan quit working in my Alfetta GT because the sender in the radiator was (temporally) not working (later on it tested out perfectly).

I replaced the sender with a good used one and also changed the fan. What happened in the first place was that the original fan was hitting the edge of a radiator hose and it stopped working. However the fan checked out fine, though the four blades had a chip out at the end.

Now this sender is working sometimes, sometimes not. I'll be driving about 80 miles round trip this Sunday, almost all on the way freeways, which can quite easily jam up in one particular area only about a mile, but absolutely no place to turn off or even pull over. Meaning, that's when it heats up and there is nothing to do but keep creeping along.

Yes, I'll be buying a new sender.
 

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1966-2013
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You can take mucho load off the switch if you put a relay in the circut.

If there's alread a relay in the circut, tie your switch in parallel to the existing sender.
(ie: connect it's wires to the same points as the senders wires. this will cause the circut to be fooled into thinking the sender has activated when the switch is thrown)

If there's not a relay in the circut there are two different ways you can go (other ways to do it of course, but these are the two most common/standard methods) :

1) stout wire from 12V source to fuse to relay terminal #30, switch wire 1 to relay terminal #86, switch wire 2 to convienent power source (fusebox, keyed circut, whatever), relay terminal #87 to fan +, fan - to chassis, relay terminal #57 to ground.

This will activate the circut via the switch activating the relay and thus powering the fan.

2) stout wire from 12V source to fuse to relay terminal #30, switch wire 1 to relay terminal #57, switch wire 2 to chassis, relay terminal #87 to fan +, fan - to chassis, convienent power source (fusebox, keyed circut, whatever) to relay terminal #86.

This will activate the circut by grounding the relay via the switch.

Going with a key controlled relay terminal #86 source will cause the fan to turn off with the key is the switch is still activated.
Going with a constant power source on relay terminal #86 will cause the fan to not shut off with the key if the switch is still activated.
 

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Discussion Starter #3
Darren, I'm hoping the 'bypass' is only needed for a few days. The radiator fan has a relay - Fan Relay - so my thinking was all my fairly short wires (41" to be precise) to the switch would have little effect on the running of the fan - unless the switch is way too flimsy to handle it. However, after hooking it up, I ran the fan for a couple of minutes with my fingers on the back of the switch, and there was no apparent heating up.

I figured out how to get my radiator fan to stay on once the engine is turned off and feel the 15 to 45 seconds it runs is a good thing to dissipate heat soak - which is the reason it needs an on/off switch. Otherwise I'd just bridge the wires to the radiator's fan sender.

I have been wondering if for some weird reason that the sender's for my early Alfetta GT don't like the staying on part - though I can't think why it would have any effect since the fan cycles on and off in any event (unless a really hot day).
 

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1966-2013
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I guess I don't understand what you're trying to accomplish.

The fan cycles as you would expect, but doesn't stay on post shutdown so you want the switch to force it on, or, it doesn't cycle like it's supposed to regardless of key being on and you want the switch to force it on?

If the former, you might have something going on with the way things are wired in general as based on other models it 'should' be able to run post shutdown, if the latter, the sensor would indeed be suspect.
 

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Discussion Starter #5
Darren, apparently you skipped the later dialogue.

The rocker switch (on the dash) is a very temporary (a week) bypass for my on again off again radiator sender for a longish drive tomorrow Sunday. That's all.

I did modify my fuse 'box/unit' so that the radiator fan is 'supposed to go on' once the engine is shut off, providing it has reached the temperature that the sender switch 'closes'.
 

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1966-2013
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Nope, I got that part.

I just got a bit confused when it went from an 'emergency bypass' switch for the sender should the sender act foolish while on the road over to fidding things so that the fan ran post shutdown for a period of time to help with heat soak.

***

AFA the replacement sender that is going to be put in soon, are you going with a stock type replacement, or one of the aftermarket adjustable types that goes in the radiator bung, or hose, or fins?
 

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Discussion Starter #7
Darren, it will go in the radiator bung. I was unaware of an adjustable sender. My temp gauge needle stays pretty close to 175 year 'round, providing I don't get in stop and go traffic. Going on the basis that the gauge is accurate, I've always felt that's a bit low. However, I would imagine that a 185F sender would work fine - or do you feel that the sooner the fan goes on, the better it is?
 

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Discussion Starter #9
Darren, I'm going to switch this over (no pun intended) to a question (or several) regarding relays. Everything was fine today until I was heading back to my place (40 miles away) and returning home from the beach was very busy on the street when the temp gauge went way up. I pulled off to a side street, found some shade, and lo and behold the radiator fan wasn't working. I'll just add that I have a manual switch for the condenser's fan so that I can have it running - without the A/C on - with the engine off (or on) for additional cooling.

I figured the switch quit working so I directly jumpered the two wires from the radiator's sender. Fan still wouldn't go on. I got out a piece of metal to turn the fan blades, wouldn't move. As I stared at it the fan it went on (I still don't know why). Before I got on the freeway, I checked and the fan wasn't working again but I made it back fine since I didn't run into stop and go traffic.

I could have made this piece shorter, but I figured the fan's relay was the only element I hadn't figured in. Turns out the relay was really iffy as to just jiggling it, it would go on, then I'd push down on it and the fan would quit. Jiggling the two wires to the relay didn't affect the fan's running.

I'm not sure if you're familiar with the Alfetta's relays or not but they're SIPIA's and the number is 0440. I switched in a different 0440 relay and it seemed to work better in that with the fan running I could wiggle it around and it didn't affect the fan's running.

How can you tell if a relay is bad? I removed the metal housing and all looks good in side, however the outside of the case looks as if there was a lot of heat on one side + both wires from the relay also have indications of being very hot at some point.

Is there a good test for relays or is it a matter that they work or they don't work (though this one seems to be an intermittent)?

Quick background: Recently when I first noticed the radiator wasn't working, I realized it was because the fan had been hitting the edge of the lower radiator hose (blades had a groove in them) and apparently it burned out either or both the fan or the sender. So I switched in different ones - though both the original fan and sender checked out out fine.

My theory is that the relay was the weak link and a fresh (okay different) relay would solve it all. Buy it?

I am thinking of going with much heavier wire for this circuit.

One last thing, while I wouldn't know what type of relay to get, do you think it would be a good idea to replace the old relay's with new Bosch ones?

If this isn't your area of expertise, I'll quickly move it over to a separate thread - though you seem to have a very wide area of knowledge on our cars.
 

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For me, relays are either good or bad. There is no intermittant. (well, if there is, its because the relay is bad, thus needs replacement)

Sipea 0440 = Bosch 0 332 014 125
This relay is also commonly used for horn, power windows or heated rear window relay if you wanna juggle around with what you may have on hand. It's a 'dual 87' type relay, though for what you're using it for that's not really important.

Point of interest: Bosch was aquired by Tyco a few years back, so if you have difficulty finding them by the Bosch # the Tyco site would be the place to start hunting the new number (IIRC they have a part # converter tool there) then you could hit the parts counter with that in hand to obtain them locally.
 

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Discussion Starter #11
Darren, thank you very much. I'm very surprised that a company bought Bosch out. I thought they were a behemoth who were beyond being acquired.

Off hand do you know the Bosch number for the 0441 relay? I have one of those though forget which one it's for.
 

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Discussion Starter #12
Darren, after going to Google I realize that Tyco is just handling the relay parts from Bosch.

I haven't searched the earth, but the 0 332 014 125 relay is extremely hard to find on Google. I also plugged in the Sipea 0440 relay and on the first page of Google all that showed up were its use on Alfa's. Could this be an Alfa specific relay?

I guess I need to go to take a relay 101 course, to see what else will work. I would think this type of relay is extremely common - at least for older cars. I have no idea how electronic systems impact on relays.
 

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No need to do google~fu

Call it in or take the # to Auto Zone, Napa, Advance Auto or simular and they can cross reference it to what they may have in stock or order one if they don't.

You could also find an automotive electrical repair shop that has the 'Bosch certified' or 'Bosch Authorized' sticker/sign/whatever and they'll prolly have a pile of them.

Just make sure to visually check that the terminals are a match AFA thier designation #'s as it's not unheard of for a counter jockey to hand over one that has an 87 and 87a instead of a dual 87 simply because they don't know any better and are doing the 'grab the first one' because they don't realize that while they all may look alike, they most definitely aren't.

Or, if you really want to do the google thing, I came up with this but I don't actually know if they are all Bosch brand, just equivalent fitment. (FWIW, its fitted into several makes of car, up to and including some from the late 1990's)
 

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Discussion Starter #14
Darren, I'm of the old school that if it doesn't cost much (I'm talking about new items) it is most likely worth what you pay for. There are tons and tons of cheap relays out there - one thing I do know about relays. The Sipea's seem to be well made and as I said, the one I removed the case from looked brand new. Meaning, if I can get a known quality relay, then I'll replace mine.

All of the car parts places around here generally stock cheap items since that is what their clientele want - cheap. Also, they are helpless unless you give them your year, make, and model.

Awhile back there was a guy/shop who drove an Alfa and who stocked quality European parts and is where I got some Bosch relay's for the starter. Unfortunately the economy got to him.
 

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I agree.
Better is best.

That being said, you can usually find Bosch stuff through the local counters even if they don't happen to have any out in the isles with the poop ones they regularly push.

Sipea on the other hand is prolly gonna be difficult to locate (do they even still exist?)
Perhaps one of our European members would have a better line on them.
 

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If your fan would not turn once, something is wrong with the fan or fan motor. Was the problem you mentioned earlier of the fan hitting the rad hose, and now it spins easily all the time?

It's possible the fan brushes are worn and could jamb the fan motor. If the fan was hitting something, you have a serious mechanical mess - something is bent or pushed out of place. Sounds like you have work to do!

None of this has anything to do with having a relay or a switch. Fix the real problems.

Robert
 

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Discussion Starter #17
Thank you all, as of now the fan seems to be working fine. Even in our coolish (low 70's) weather, when I drive for a bit on the freeway and streets, the fan always comes on once I shut off the engine (as I modified the fan relay connection to do).

Apparently a combination of a 'new' sender, 'new' relay, and tightening up the fuse contacts did the trick.

While I hate to replace everything when there is a problem, sometimes that is what is needed.
 
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