Cooling fan INOP question

[e30gentry]

I think I may need a new fan:
I have battery voltage going to the fan and good ground.
I don’t have a way to measure PWM but there is around 4v signal.
A/C control on max or unplugged the fan does not come on.
With the oil sensor (on oil filter housing) disconnected the fan does not come on.

I know the the fan relay is around year old with a new OEM part as it was replaced last year.

Am I missing something or is there another way to test the fan before pulling the trigger and purchasing another one?

[Redd]

I know it's relatively new but I'd still check the relay first.

[Scrippy]

If you have INPA or ISTA you can trigger the fan on. While doing this you could check the fan relay coil points for voltage. Then you could put 12 volts to the fam relay on a bench and meter your normally open and closed points for change when you apply coil power. If you are getting voltage at the fan connector all of those parts are working and it may be the fan.

[e30gentry]

Originally Posted by Scrippy

If you have INPA or ISTA you can trigger the fan on. While doing this you could check the fan relay coil points for voltage. Then you could put 12 volts to the fam relay on a bench and meter your normally open and closed points for change when you apply coil power. If you are getting voltage at the fan connector all of those parts are working and it may be the fan.

Wish I had INPA or ISTA. Trying to find my android that has protool on it as an alternative but haven’t been able to find it.
Definitely power going to the fan relay.

[RocketyMan]

Originally Posted by Scrippy

If you have INPA or ISTA you can trigger the fan on. While doing this you could check the fan relay coil points for voltage. Then you could put 12 volts to the fam relay on a bench and meter your normally open and closed points for change when you apply coil power. If you are getting voltage at the fan connector all of those parts are working and it may be the fan.

This is the way to T/S this issue.

[Scrippy]

Originally Posted by e30gentry

Wish I had INPA or ISTA. Trying to find my android that has protool on it as an alternative but haven’t been able to find it.
Definitely power going to the fan relay.

So if you are measuring power to the fan relay it could be one of two…..1 power that is always there and only supplied to the fan when relay is in closed state and 2 power to energize the relay coil and GIVE power to the fan via a closed contact. I assume you are measuring the power supply to the fan, as that would be constant but it’s only used when the relay energizes and changes the contacts. The coil power would only be present when the DME wants the fan on due to heat. This is why triggering the fan via software helps. We could turn fan on and measure for 12VDC and if we find it we turn the fan off expecting to see the voltage drop. Otherwise you would have to let the car warm to the point it wants the fan. Does the relay have a simple schematic on it? I see one on realoem but it could be generic. I’ll post it from my laptop for ya.

Update:

1&2 are coil power but I’m not sure which is ground or positive. A multimeter will read negative -12 if you reverse, so that’s a way to find out. Not constant and only on when needed. Measure across 1 & 2 and trigger fan on to see voltage. (What you need to verify).

3 (Common) will show 12VDC constantly with ground.

5 (NO) With ground would only show power for fan when needed.

[e30gentry]

My voltage measurements are at the fan connector, not at the relay.

[Scrippy]

Originally Posted by e30gentry

My voltage measurements are at the fan connector, not at the relay.

Hahahaa, well I wish I caught that or I wouldn’t have waisted your time. My bad.

[e30gentry]

Originally Posted by Scrippy

Hahahaa, well I wish I caught that or I wouldn’t have waisted your time. My bad.

Any and all feedback is great feedback!

[e30gentry]

Update, I can command fan on with Protool???

[e30gentry]

Originally Posted by Scrippy

Hahahaa, well I wish I caught that or I wouldn’t have waisted your time. My bad.

Reading into your message a lot more and will be working this today.
Happened to have another fan, broken blades so I took that apart and tried swapping it over and still no luck.
But I’m going to pin everything out see what my findings are

[e30gentry]

Originally Posted by Scrippy

Hahahaa, well I wish I caught that or I wouldn’t have waisted your time. My bad.

I can turn fan on via request with Protool.
I disassembled and replaced the power side of the fan motor since I had a broken one laying around and still same.

Measuring at relay
X17279 and X17278 I have battery power regardless of what I do. Without tapping into the two wires at X17282 I’m not sure what they measure.
The fuse (F26) 5a is good, this is on the red/green wire on X17282.
F104 the integeral fuse at the batter I assume is good since there is power to the relay and fan.