Overheated, Fan issue, Radiator

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ylbill

Overheated, Fan issue, Radiator

Postby ylbill » Fri Aug 11, 2017 1:58 pm

Car overheated sitting in driveway and now have two issues. Fan didn't come on, checked lower house and it was cold, so I purged system and got that corrected. but fan still doesn't come on automatically when up to temp. Tested fan and it works, just doesn't turn on when temp is up around 190.

Also, since overheated, steam from lower part of radiator, so it seems it did some damage to radiator and probably needs replacing.

Suggestions on why the fan won't come on and resolve of steam from lower radiator.

New radiator and switch??

Thanks

Sscottdvm
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Joined: Wed Jun 14, 2017 3:46 pm
Your car is a: Fiat 124 1971

Re: Overheated, Fan issue, Radiator

Postby Sscottdvm » Fri Aug 11, 2017 10:52 pm

Just had the same problem with the fan not coming on. Turns out the wires going to the switch were corroded. It's either the switch or the ground wires. If you short the wires going to the switch and fan works then the switch is bad. If not probably just check the wires.
1978 Fiat Spider 124
BMW M3 2008
Subaru Forester 2008
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nelsonj
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Your car is a: 1972 Spider 124

Re: Overheated, Fan issue, Radiator

Postby nelsonj » Sat Aug 12, 2017 12:24 am

Horn and fan share the same fuse. Does your horn work?
If no, check the fuse first.
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Simi Valley, California
Spider 1800
Romans 10:9

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 12, 2017 4:39 am

Sscottdvm wrote:Just had the same problem with the fan not coming on. Turns out the wires going to the switch were corroded. It's either the switch or the ground wires. If you short the wires going to the switch and fan works then the switch is bad. If not probably just check the wires.

Yes, I shorted the wires and the fan came on, so guess I need a new switch. Thanks

That's the cheap small job. I guess I'm more concerned with radiator. Steam from lower area of radiator, seems like the overheating did some damage. I'm going check again, because there was coolant over due to purging. I want to be sure the steam wasn't from the coolant overflow. I don't think it was because the steam looked like it was pushing out. More time and $$.
Last edited by ylbill on Sat Aug 12, 2017 6:08 am, edited 1 time in total.

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 12, 2017 4:45 am

nelsonj wrote:Horn and fan share the same fuse. Does your horn work?
If no, check the fuse first.

I was able to short the wires and the fan does come on, so I did confirm that the fan works. Looks like a new temp switch.

Should I start with just the switch or does it sound like the radiator is bad too? There was some coolant overflow, so I was hoping it was coolant evaporating, but it doesn't seem to be going away.
Like the verse!

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DUCeditor
Posts: 490
Joined: Sun May 23, 2010 7:36 am
Your car is a: 1977 FIAT 124 Sport Spider
Location: Monadnock Area, New Hampshire USA
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Re: Overheated, Fan issue, Radiator

Postby DUCeditor » Sat Aug 12, 2017 9:39 am

In all the (almost 30) years I've owned my Spider I never was aware of the fan coming on. Nor has it ever over-heated.

I aways assumed that was because I never drive it in traffic -- just on open, free, two-lane roads.

But still, when I was replacing my water pump, and thus renewing my coolant (after a flush), I replaced the switch at the bottom of the radiator.

The fan still doesn't come on that I am aware of. Or the car overheat.

????

-don
Italian motorcycles. An Italian car. An Italian wife. What more could a man desire?

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 12, 2017 10:14 am

DUCeditor wrote:In all the (almost 30) years I've owned my Spider I never was aware of the fan coming on. Nor has it ever over-heated.

I aways assumed that was because I never drive it in traffic -- just on open, free, two-lane roads.

But still, when I was replacing my water pump, and thus renewing my coolant (after a flush), I replaced the switch at the bottom of the radiator.

The fan still doesn't come on that I am aware of. Or the car over-heat.

-don


Thanks for your input Don.

I guess if you haven't had a problem, why mess with it.
I know for sure if my fan doesn't come on my car will over-heat.

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 13, 2017 12:35 pm

nelsonj wrote:Horn and fan share the same fuse. Does your horn work?
If no, check the fuse first.
Checked the horn and it worked.

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 13, 2017 1:10 pm

Horn worked, fan works when shorted.
Last edited by ylbill on Sun Aug 13, 2017 1:15 pm, edited 1 time in total.

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 13, 2017 1:11 pm

ylbill wrote:
Sscottdvm wrote:Just had the same problem with the fan not coming on. Turns out the wires going to the switch were corroded. It's either the switch or the ground wires. If you short the wires going to the switch and fan works then the switch is bad. If not probably just check the wires.

Yes horn works. I shorted the wires and the fan came on, so guess I need a new switch. Thanks

That's the cheap small job. I guess I'm more concerned with radiator. Steam from lower area of radiator, seems like the overheating did some damage. I'm going check again, because there was coolant over due to purging. I want to be sure the steam wasn't from the coolant overflow. I don't think it was because the steam looked like it was pushing out. More time and $$.

brackie1
Posts: 523
Joined: Sat Dec 14, 2013 1:24 pm
Your car is a: 1978 124 spider
Location: Winston-Salem, NC

Re: Overheated, Fan issue, Radiator

Postby brackie1 » Sun Aug 13, 2017 1:51 pm

if lower hose is still cold, it indicates you may have a thermostat problem. They aren't expensive so I would replace it first before assuming you have a bad radiator.
Gene
North Carolina

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 13, 2017 1:57 pm

brackie1 wrote:if lower hose is still cold, it indicates you may have a thermostat problem. They aren't expensive so I would replace it first before assuming you have a bad radiator.
Thanks Gene, I did check the lower hose and it does get hot. Last time I ran it everything ran fine. Something within the cooling system chain didn't appreciate it getting too hot and overheated. Would the lower radiator switch stop working because it overheated?

brackie1
Posts: 523
Joined: Sat Dec 14, 2013 1:24 pm
Your car is a: 1978 124 spider
Location: Winston-Salem, NC

Re: Overheated, Fan issue, Radiator

Postby brackie1 » Sun Aug 13, 2017 7:14 pm

Don't think so. Sounds like a bad fan switch. I know I've put two in my '77 in the last 4 yrs. You might also check the ground notorious for going bad.
Gene
North Carolina

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Fri Aug 18, 2017 3:05 pm

Okay, Still having issue with fan not coming on. Just flushed coolant and installed new fan switch. Still no fan when at temp it used to come at prior to the overheat. Fan works, bottom hose hot, new fan switch. What else should I be checking, test replacing? Thanks

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RRoller123
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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Fri Aug 18, 2017 3:51 pm

Check the ground coming off of the fan switch. Its connection is over in the cluster on the driver's side fender well. The switch input side from the fan is always hot, the switch gives it a path to ground. Thus it can run when the ignition is off.

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