Electrical or Mechanical Gremlins?

[Sxynerd]

My 91 TA is irritating me. I got this car for free and I thought it would be something fun to beat around in when I'm not in the mustang. It's got a fresh build on the 305.

Conditions and issues...

• It's 4* below today.
• Electrical problems are abundant like selective heat and the more apparent issue, the Coolant fans. (Like my wife, it turns on when it's good and freakin ready, lol)
• New Radiator
• New water pump
• Temp rides at about 220 while driving in cold temps the temp will start to rise up to the red until I pull off and slow it down. Then after I come to a halt the temp will start to go back down. (without the fans turning on)
• Then miraculously the fans will turn on.

Any, Ideas?

[lozanoa11]

bad fan relay. bad coolent temp sensor. bad thermostat. bad coolent. just a few ideas

[98blackbeauty]

besides one of the other mention things could also be a air lock did you purge the system after new radiator was installed. Did you change thermostate? what temp is in there? should be 180

[WMCCjames]

You have two seperate issues

Did this temp thing happen before the water pump and rad was replaced?

[Sxynerd]

I just started driving the car up til now it was just in storage. It has the correct Tstat.

[Kwazrollinz28]

Time to burp the system

[TSTONE]

the engine temp issue sounds like an air pocket to me

[Sxynerd]

I'm getting ready go out and beat on it with a hammer right now, I'll post back and let everyone know how it went or where I bury the body when I'm done.

[Sxynerd]

OK new symptom... The fans do NOT turn on unless the A/C/Defrost is on.

What is the name of the switch that turns on the fans when needed?

[lozanoa11]

ect (engine coolant temp) sensor should signal the pcm to turn them on.

[Sxynerd]

Where is that?

[Sxynerd]

OK so I've ruled out the
Temp sensor to the ECU
The relays
Fuses
Both fans do work (hell the a/c even turns on one of the fans)

Any help would be great!

[WMCCjames]

Did you put it on a scanner to see what the temp sender was seeing?

[Sxynerd]

No, I didn't. Is there more than one sensors? I couldn't see one on the passenger side. The one on the drivers side (green wire) is the one thus far I've been screwing with. I'm starting to think it's just the gauge sensor.

[WMCCjames]

So how did you rule it out of you didn't put it on a scanner?