Rad cooling fan

[jenkinskg]

OK, I was given another fan from a spare car original seller had, it does same thing and one in car.
Runs slow and work ok with ac ruinning, as long as compressor is turned on I have radiator fan running, slow speed only, not sure if it would get faster with higher engine temp.
Does not overheat, stays at about 193 195 Deg F, even when I ran it up to 205 def f fan would not go any faster ac on or not

So I suspect ecu relay to switch on fan, traced it to a pin maybe 7 as I remember

I have a spare ecu to open and play with, before I mess with one in car, Will see if pin traces to a power trasistor of something like that , then I spare parts.

[Botbasher]

I don't believe this is a PWM fan.... What is the actual voltage (while the fan is connected) you read at the fan?

It is sounding like you have a high resistance connection somewhere in the line.

Say you have 10v at the fan. Start tracing that line back until you see 14.1v (or whatever your alternator puts out while on). The junction or component that has 14.1v on the input and 10v on the output is bad (unless it's a switched component like a transistor, it these are not PWM controlled fans... Simply on/off).

Alternately, you could jump B+ (Battery) to the + of the fan. It should spin up to full speed. That tells you the fan is good. Then it's just tracing the supply line from the fuse block to the fan.

One is forward troubleshooting.... The other is reverse trouble shooting. You eliminated the fan (unless both are similarly bad).

I'd focus on the fan relay or high power connections along that line being corroded. They work OK to pass poser but can't supply the current to run the fan at max.

Check the V at the fan and work back. It's usually a shorter trip!

K "troubleshot" S

[Botbasher]

Hey jenkinskg.... How'd you fare with this one?

Was reminded of you this morning while troubleshooting a unit.... wondered how it resolved. Similar issue. Low power to heaters. Found SSR (Solid State Relay) would partially turn on supplying good voltage (208V) until you asked it for power, then it dropped to 96V. Tech couldn't figure it out.

Cheers!

K "sluethy" S

[jenkinskg]

Got it all cool, if plain water is in car, as mine was. The system does not reach high enough temp to activate fan.
Drained the system, got as much water out as I could.
Then put my evans in, now nice and hot, no pressure and stays at 195 - 200 Def F
got dash back, all working also.
driveable now, need to find gremlins in alignment, may just need alignment, maybe a bushing, not sure yet