So when I jumped the 2 wires coming from my fan switch on my 84 Duke the relay in the front corner drivers side just clicked. and the radiator fan did not turn. I had another relay (used of course) and when I plugged it and and jumped the 2 wires coming from the fan switch that one clicked as well and again the fan did not turn.

I am thinking that both relays must be bad, kind of like when your starter just clicks. Am I thinking correctly about this?

This Fiero has AC and a 2 speed fan relay that if I am right the 2 speed fan relay is no longer avalible. O'Reilly did not have one and they said it was special order IF they could get one.

I am thinking of converting from the single 2 speed relay to the 2 relay set up so I can retain the 2 speed operation of the fan.

Am I looking at this the right way?

Thanks for any advice!

Will the fan run if jumped with a 12 volt power source??
If the relays are clicking sounds like both the ones you have are working.

Yes the fan runs if I jump it with 12v. I have spliced into the wires going directly to the fan and have it hooked up to the fuze box right now.

Have you checked for broken wires, bad connectors ground path?

While I slowly tear apart and rebuild my 84 2m4 (daily driver) I discovered an interesting problem (overheating). While I was checking all the lines related to that system I was stopped at the a/c radiator relay in the front LH light bay. I went all over the area (in addition to deliveries that said 'it was the part i wanted' and could not secure a new one. I guess I could pull an old one, but why-- the corrosion could be just as bad. So I set out to making my own using the 'cave' instructions. BTW this is a 2-stage fan. I did open the unit and aside corrosion at the leads, overall it looked fine. None the less, it is being replaced.

https://www.facebook.com/media/set/?set=a.2991891447697.136358.1574472295&type=1&l=5a272bd583

I did a remake of the radiator fan relay. See photos. Will tighten it up and relocate in front compartment on next phase.

[IMG]https://www.facebook.com/media/set/?set=a.3021754554256.136856.1574472295&type=1&l=8151b6a3ca[/IMG]

[This message has been edited by 1ofakind (edited 02-14-2012).]

quote Originally posted by Mitch Perry: Yes the fan runs if I jump it with 12v. I have spliced into the wires going directly to the fan and have it hooked up to the fuze box right now.

Careful--that fan pulls a lot of current. I believe the relays are probably good. The clicking is the relay engaging, but that doesn't mean the contacts are carrying the primary 12 v accross them to the reistor and on to the fan or to the the high speed wire that bypasses the resistor.
My guesses:
1. Bad resistor--and they are hard to find.
2. Bad fusible link that feeds the high current side of the relay.

There are 2 sets of circuits in that relay. One is fed from the fuse box, to the relay, and back to the temp switch on the engine. When the contacts in the temp switch closes, that provides ground to complete the circuit that operates the contact coil in the relay. The other circuit, is fed (hot at all times) from a fusible link to provide the high amp circuit and voltage to the input side of the relay contact pin. If there is voltage present at that relay pin, current flows accross the closed contacts and on to the resistor and fan.
(there are actually 3 individual circuits, since the 84 uses a cooling fan switch with hi and low contacts).
Anyway, I would suspect you don't have a voltage potential at the relay for your high current circuit.

From the 84 factory Fiero manual. ssuming you have already ruled out the fuse and cooling fan switch on the low amp circuits, you will want to look at the circuits on the far left side of this picture--the high current circuit.

[This message has been edited by maryjane (edited 02-14-2012).]

MJ

1. RE: fusable links are currently all good and relocated by battery. This wasn't the case before they had blown several prior, this could have been the source of the brown (off fuse H-AC) and green wire (A/C Clutch + fused) within the car frying out.

2. RE: High current side inspection: read above most likely related. The A/C is disabled currently. Fan power does come on with a/c selected on the control head.

3. RE: relay dismantle: I did tear it apart and remade it with two relays, I think I attached the pics above. Grounded out hi and low and received response from fan.

There is one addition problem I am working on that ties into this circuit and that is the coolant temp switch and the temp sending unit. The first goes to the ECM and the second is supposed to be tied into where (the dash / oil pressure switch)? I have reviewed several schematics and none of them include the temp sending unit. I started wondering if it was in the wording used.

1ofakind:

I'll have to look at the 84 factory manual a little later, (gotta run to town right now) but I don't remember the temp sensor wiring going thru the oil pressure switch. One of the sensors operates the dash gage, and the other sends data to the ecm, but I don't remember off the top of my head which one also kicks on the low oil press/high temp light.
I'll look when I get back from town.

quote There is one addition problem I am working on that ties into this circuit and that is the coolant temp switch and the temp sending unit. The first goes to the ECM and the second is supposed to be tied into where (the dash / oil pressure switch)? I have reviewed several schematics and none of them include the temp sending unit. I started wondering if it was in the wording used.

I get a similar clicking noise everytime I re-connect my battery after any kind of service. I've not had any problems other than an occasional code after sitting at idle for a while, like in a drive-thru. Is this something to worry about? AC is not hooked up - 87 V6 transplant.

Jonathan