markymac

I've recently removed all smog and emissions from my 84z28. Installed new bump stick,new valve springs, holley intake and a holley avenger 570cfm carb.
My issue is the electric fan. If I'm correct sensor on thermostat housing is for the computer , passanger head sensor for the fan and driver side head sensor for the gauge. My gauge dosent work and the fan will not kick on .
Any help and or suggestions would be greatly appreciated . Oh and the engine has never run so good. Instant throttle response and great power .

sofakingdom

iTrader: (1)

You are correct on the sending unit, switch, & sensor ID.

Try replacing the gauge sending unit and the fan switch.

markymac

Ok I'll pick the unit's up tomorrow. And see what happens.

NoEmissions84TA

iTrader: (1)

I believe the ECM, which you are no longer using, controlled the fan.
You need to wire it up with a different control circuit now.
The same goes for the torque converter if yours is an automatic transmission.
Did you also switch to a non-CCC distributor? The ECM controlled that also.

sofakingdom

iTrader: (1)

ECM was not involved with the fan in the carbed cars. That would have required too much computing power on its part. Just the switch.

markymac

So considering the wiring is fine which I believe it is,it's probably the sending unit's? And the distributor in the car seems to work just fine.

naf

iTrader: (7)

a visual inspection of the fan relay will often reveal some issues at the wiring connector that may, or may not, require attention and effort before the fan can work properly

markymac

Where exactly is the fan relay? Are they expensive to replace ?

naf

iTrader: (7)

fan relay is near the brake booster. the relay is a fairly stout piece and probably does not need replacement.

the wiring connector, OTH, tends to degrade and expose the conductors

find the relay

test for constant 12V to the power lead

test for IO 12 V to the positive control lead

ground the negative control lead and the fan should turn on

If either of the four diagnostic steps above fails, a new temp switch won't do any good

markymac

I have 3 relays next to my brake booster 3 relays, thinking the one to the left would be fan relay ..?

naf

iTrader: (7)

Should be but best to check.

Providing all the wires are where they should be and connected to what they should be connected to, you can pull the connector and jump the two large gage wires. Fan should spin.

or you may need to do a continuity check between the fan power lead (larger gage wire that's not constant hot) to the fan motor connector.

sofakingdom

iTrader: (1)

Nope; only one.

Look for a thing that has a big fat red or orange wire, a big fat black w/ red stripe wire, and a small green or green w/ white stripe wire, all going to it. The thing that has those wires, plus acoupla more, is the fan relay. I think it's the left-hand one of the 3 objects in your photo but I could be misshapen, might be the center one. (the right-hand-most one BTW is the MAP sensor)