Hey all, it's been a while

Anyway,
I've been searching and digging for a while to sort out a problem with my cooling fan not turning on my 86 305TPI. It is an original single fan setup.

So I ordered a new fan switch from Summit and go about to replace it, and first all I found was the temp gauge sensor on the drivers side cylinder head.

However, I just noticed there is something on the passenger cylinder head, but it appears to be just a plug or something?? It looks like a switch/sensor but it doesn't have anything connected to it, nor does it appear to actually have a connector And there is no lose wire nearby to be found..

So, the magic questions are:
1. Where. IS the fan switch on an 86 single fan setup?
2. What color is the wire that goes to it and where does it come from in the harness?

Thanks a million!!!


Ken

 

im not sure about export models.but a us model 86 with a single fan does not use a fan switch.the fan is controlled by the computer .now, you may have a bad relay.it is to be found at the top right hand corner of the radiator. good luck

 

and also our fan doesn't kick on until the temp reaches 230-235.You may want to consider buying a laser light temp.tester.just to make sure your temp.gauge is reading correctly.I know my gauge is off about 20-30 degrees,now I'm not so concerned when the temp reads 240 and the fan hasn't kicked on yet.

 

Hey guys, thanks!

Mine isn't an export model, I bought i in the US while living there

Anyways,
Really ? There is no fan switch Now that's odd..
The relay is good as I can get it started by pulling the A/C pressure switch.
However it never kicks in until the temp gauge is in the red and if in Heavy traffic or standing still, I can hear it starting to boil just when the fan kicks in, so I believe the gauge is fairly correct, but I have a spare one I can swap with to check.

Thanks again!


Ken

 

No fan switch, IIRC the ECM grounds the Green or Green (white stripe) going to the fan relay.

If you want to get into burning your own chips, you can change the Fan On and Fan Off temperatures. I live in TX, so it gets really hot here in the summer and ended up switching to dual fans, even with the chip tuning.

Hayden sells a couple cooling fan controllers, Hayden part# 3652 for single fans (set temperature) and Hayden part# 3647 (adjustable temperature). It has a temperature probe that you insert through your radiator. It has a relay that comes on and turns on the fan. You could bypass the factory fan relay altogether, or install the Hayden thermostat in addition to the factory stuff (use the ECM as a backup in case the Hayden relay fails). There are some older threads about this on this site, I was running both relays awhile back.

If you decide to get a Hayden controller, grab an extra 40amp relay from the parts counter, a borg warner one (lifetime warranty) if possible because those cheap relays tend to go out when its hot out and most inconvenient.

 

I'm seeing a ghost haha...If you had a 2.8, you would have a redundant fan switch as backup. You may have a temp sensor going bad on the front of the intake base. That's how the ecm knows when you've reached 220°f. It will throw fueling/timing off a little as well if it not accurate.