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Discussion Starter #1 (Edited)
"Troubleshooting 164 Cooling Fan System Part one"

Troubleshooting 164 Cooling Fan System

Troubleshooting 164 Cooling Fan System
First check cooling fan motor and motor power circuit to see if fan motor P2 will run without worrying about whether control circuits controlled by ignition switch B2, fuse F14, fan relays, low speed resistor, A/C trinary switch or radiator switch are working.
1. First off verify fan motor P2 will turn by hand. If motor seized remove, replace bearings or replace motor.
2. Verify 12v power (HOT AT ALL TIMES) at both sides of 40A fuse bar G254 on false firewall. Replace cracked or burned fuse bar with new Alfa one or a 45A Honda fuse bar. Do not hot wire with no fuse bar.
See first picture, I used multimeter set to DC volts, test light showing amber and Radio Shack battery/alternator tester to show battery voltage at G254 fuse bar

3. Verify 12v power coming through fan motor P2 from 6 mm red wire from fuse bar G254 by checking 6 mm brown wire from fan motor that goes into low speed resistor O22 (O34 24v) 2.5mm smaller brown wire and to pin socket 87 of high speed relay I68 (I100 24v) for >11.5v. Disconnect this 2.5mm wire from fan resistor in radiator fan shroud and ground it to chassis fan should run. Resistor connector also has a blue 2.5mm wire
See second picture showing using test lamp and Radio Shack tester to show battery voltage is getting into and out of fan motor P2

4. If >11.5v at either 6 mm brown wire in step 3 ground 2.5mm brown wire disconnected from resistor or at 6mm brown high speed relay I68 (I100 24v) at relay socket pin 87 to engine or chassis to make fan run. If motor will run on high speed, not noisy or dragging down or not blowing 40A fuse bar now you can check out control circuit.
5. If no voltage getting through fan motor to 6 mm and 2.5mm brown wires, now disconnect red and brown wire connector from fan and check for 12v at red wire coming from Fuse bar G254. If red wire has power, with fan motor disconnected check fan motor itself for open circuit with ohm meter. No power trace red wire back to 40A fuse bar repair wire or fuse. If fan motor has open circuit replace or repair motor.

Once motor runs by either grounding 6 mm at relay socket 87 or 2.5mm brown wires going to resistor then it is time to move on to control circuit.

Troubleshooting 164 Cooling Fan System Part Two

Second, once you have cooling fan power circuit and fan P2 running by checking out that side of equation it is time to check out the control circuit starting with the ignition switch B2, the 7.5A (10A 24v) Fuse F14 in main fuse box G1 under dash to left of steering column.

1, Verify power to F14 fuse with ignition switch on, replace fuse if required and recheck if no power to fuse, locate ignition switch wire connector to right of steering column and check pink wire in connector harness for power with key on. If no power in pink wire with key on jump red wire to pink wire and check fuse F14 for power if now you have power there is problem with ignition switch contacts.
2. Verify low speed fan runs with key on by locating either A/C trinary switch Q20 behind false firewall on A/C receiver dryer and jump brown to black wire and see if low speed relay I1 (I99 24v) clicks and low speed fan runs or locate connectors to radiator thermal switch L6 (L33 (24v) and jump 1 mm brown wire (hooks to white wire at switch) to black ground wire in same connector or to chassis to see if low speed relay clicks and low speed fan runs.
3. If low speed fan runs by grounding 1 mm brown, then you need to verify low speed contacts of radiator thermal switch comes on at specified temperature setting for specific switch installed. Alfa switch set to come on at about 198F (92C).
4. If low speed relay clicks but fan motor does not come on you need to verify low speed resistor O22 (O34 24v) in back of radiator fan shroud is good or bad. Locate connector with 6 mm brown and blue wires that goes to resistor. Jump two wires together and ground low speed relay 1 mm brown wire as stated in step 2. With blue and brown 6 mm jumped together fan should now run on high with low speed resistor bypassed. If so resistor probably bad so run a continuity test with it disconnected and check resistance. An open reading means resistor is bad.
See third picture showing meter set to Ohms and leads hooked to resistor wire terminals verifying resistor good and has continuity by meter reading 5 ohms
5. Verify high speed fan runs with key on by locating 1 mm brown-white that hooks to red wire from radiator thermal switch L6 (L33 24v) high speed contacts and jumping it to black wire in low speed connector or to chassis to see if high speed relay clicks and fan runs on high speed.
6. If relay clicks and fan runs you need to verify High speed thermal contacts in radiator switch come on at 206F (97C) if Alfa switch is installed.
7. If neither relay will click you need to verify pin socket 86 on either relay pink-white wires are getting power from F14 fuse.
 

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Awesome!!! Steve I love you

When can I take you out to dinner? :)

Your write-ups are awesome.

Now to allow the cooling fan circuit to be active when the ignition is off (after-run fan), the two pink wires on the low speed relay need to be connected to the fusebar though a 10amp fuse?


P.S.

what is the part number for the low speed resistor? can i get it at iap/difatta?
is timing belt replacement guide next? ;)
 

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Discussion Starter #3 (Edited)
alfar0meo said:
Awesome!!! Steve I love you

When can I take you out to dinner? :)

Your write-ups are awesome.

Now to allow the cooling fan circuit to be active when the ignition is off (after-run fan), the two pink wires on the low speed relay need to be connected to the fusebar though a 10amp fuse?



P.S.

what is the part number for the low speed resistor? can i get it at iap/difatta?
)
Depends on which speed you want to be after-run fan. Only one of relays should be wired to new 7.5/10A fused hot wire. Wires are pink-white ones not just pink and you need to isolate pink-white one going to pin socket 86 of relay you want to after-run. I suggest low speed I1 (I99 24v) so fan runs slower and to a lower temperature.


The new improved low speed fan resistor for the 164 with two speed fan and two contact (3-wire) thermal radiator switch is now 60609114 (started with production of MY1994 chassis 6296308) and now the resistor of choice for all older 164 with old style resistors. See TSB 07.94.02 (kit 589-4444 appears to be no longer available as it was superceded by just 60609114 resistor in June 1997. You can crimp on new female connectors to your old Blue and brown 6 mm wires if ends fried. Canceled TSB said not to solder on terminal ends but use crimped style and cut back wires to good clean wire first.

Difatta carries 60609114 resistor as I am sure does IAP and many others.
There is another one originally called for in the now canceled TSB 07.94.01 numbered 60809136 that will work but newer one has new style wire connector on it.
 

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Discussion Starter #4
Added some pictures of testing to first post showing three pieces of test equipment -- multimeter, test light, and a Radio Shack voltage tester with go no go lights.

This post is a copy of a rough draft "work in progress" for an article I hope to submit soon to Alfa Owner.
 

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Where can I locate relays I1, I68 and resistor O22 and thermal switch L6? I just want to make sure before I blow off anything.

thanks,
-Pavan.
 

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Discussion Starter #8 (Edited)
Cooling fan relays under black plastic cover farthest from coil, resister inside upper corner of fan shroud under relays and thermal switch in side tank of radiator next to headlight. All components right together. Pull plastic cover between headlight and a/c condenser/radiator to see thermal switch and unbolt coil and relay bracket to get better access to resistor.
 

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Discussion Starter #10 (Edited)
I corrected my post above. I had a brain fart. Cooling fan relays under cover closer to air cleaner. Fuel pump and motronic computer relay with red stripe under cover closest to coil. SORRY!
 

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Ok, I followed your write-up and found nothing wrong with the electrical circuit. the fan runs at high speed and low speed at the places where you mentioned it should. Are there anyother things that I need to check why my engine rises to high temps as soon as I enter city traffic??

-Pavan
 

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Today again it went past 213F in city driving. I opened the hood and saw the fan running at high speed, does that mean that the electrical system is working fine and there is problem in the cooling system parts?? If so :eek: , what might be the problem, water pump, thermostat, hoses or anything else??

-Pavan.
 

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Sorry if I'm being redundant as I don’t know if this was stated in another thread. But have you or PO replaced the water pump on this vehicle? It sounds like the water pump is not pushing enough coolant through your system :confused: Or possible obstruction? :eek:
 

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No Idea about that, have to contact him. Anyway how can we identify any obstruction or whether the water pump is not pumping well, any devices to check this??

-Pavan.
 

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Discussion Starter #15 (Edited)
Verify your gauge reading accurate by using a laser heat gun (Sears sells reasonably priced ones) on thermostat, top radiator hose, radiator side tank near thermal switch.

Do you have good 50/50 mix of coolant?

What is outside temp (weather you are driving in now)?

Does coolant tank boil over? Temp of 212 not excess in city driving with a/c on after an interstate drive it is normal to go to about 212 but if you can't get temp to stay below that you may have a partially opening thermostat or low flowing radiator but if temp OK on highway not sure a problem.

Is this a new to you 164 or has problem just started on a car you have had awhile?
 

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Verify your gauge reading accurate by using a laser heat gun (Sears sells reasonably priced ones) on thermostat, top radiator hose, radiator side tank near thermal switch.

Do you have good 50/50 mix of coolant?

What is outside temp (weather you are driving in now)?

Does coolant tank boil over? Temp of 212 not excess in city driving with a/c on after an interstate drive it is normal to go to about 212 but if you can't get temp to stay below that you may have a partially opening thermostat or low flowing radiator but if temp OK on highway not sure a problem.

Is this a new to you 164 or has problem just started on a car you have had awhile?
The coolant was filled by the mechanic when he did the serpentine idler replacement 2 weekd before. The coolant tank doesn't boil over as far I can see. On interstate it will be always either below 175 or just above 175 and not more than that. But as soon as I enter the city traffic it goes above 212. Its more than 5months since I used a/c for the last time. No matter what the out side temps, it goes to 212 in city traffic. My commute times are mornings b/n 7-8 and evenings b/n 5-6. Actually I came accross this problem from the time I got the car, when I am driving down this car from the PO from San Diego, it did the samething and I called him abt this, he told that its normal going to 212 in city driving.

-Pavan.
 

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Discussion Starter #17
I also think it is normal if you have proper operating thermostat, thermal switch in radiator as 87C (187F) thermostat is designed to run engine about 210F when thermostat fully open. If both low and high speed thermal switch contacts work at correct temps of 198F and 206F and gauge reads correct I think you are home free.
 

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Today again it went past 213F in city driving. I opened the hood and saw the fan running at high speed, does that mean that the electrical system is working fine and there is problem in the cooling system parts?? If so :eek: , what might be the problem, water pump, thermostat, hoses or anything else??

-Pavan.
It sounds to me that your low speed fan is not kicking in (although you have done some tests). Do you actually see the low speed fan come on when you idle the car long enough? The low speed fan should keep the operating temperature at around 200F. The high speed fan should rarely come on (in my experience) if the low speed fan function is working. The problem might be a bad fan switch or bad connection around there.
 

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It sounds to me that your low speed fan is not kicking in (although you have done some tests). Do you actually see the low speed fan come on when you idle the car long enough? The low speed fan should keep the operating temperature at around 200F. The high speed fan should rarely come on (in my experience) if the low speed fan function is working. The problem might be a bad fan switch or bad connection around there.
Do ya think if the low speed fan doesn't come on, even then the freeway driving temperatures will be at 175F?... I am :confused: ...

-Pavan.
 

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It's my understanding that 212 deg F (100 deg C) is THE optimum temperature for the lowest emissions. So it is not too high, when you install a lower temp fan switch you are effectively raising your cars emissions.:eek: A 164 doesn't run at any hotter than any other properly engineered car. I think the only reason we tend to feel that are cars are running hot is because the tight engine bay and the fact that the gauge reads pretty far to the right of the gauge when it is normal. Many American cars are designed to run in the first 1/4 of the gauge to make us feel good and they don't move much no matter what the actual temp is (really, just fancy idiot lights, in effect).
Charles
 
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