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[91xr2forfun]

I've looked at previous posts, but didn't pinpoint a solution. The fan doesn't come on when I remove the green/white wire from the coolant switch located on the thermostat housing. It doesn't come on when I get the led on the AC dash switch to light up.

When I directly apply 12 volts to the connector on the end of the fan wire it runs and pulls 25 amps.

I tested the fan relay and ac relay because the wiring diagram shows they are interconnected. Both relays click and I also checked the other pins with an ohmmeter and all seems ok.

The AC doesn't work, but that's another problem. I want to solve the cooling fan problem first because that is what may cause engine problems.  The car doesn't overheat unless it's above 80 degrees AND I am going verry slow due to traffic. Most of the time the radiator is so efficient the guage reads in the safe zone, but I want the option of a fan going on.

A sensor to the ECU was mentioned in a previous post. Can you send me a pic. or tell me a page number in the manual so I can find that sensor?  How about a grounding problem for the cooling/ac system? They seem to be getting 12 volts, but I don't know how to check for proper grounding. If the AC doesn't work in a turbo capri, does that interrupt power or grounding to the cooling fan?

Sorry, it's a lot of questions, but I'm about ready to bypass everything and install a fused on/off "rigged up" switch just so I can protect the engine when in a traffic jam. I'd rather keep it stock though.

[blueamber]

If you pull the wire from the temperature switch (my book says Green w/red stripe), the relay cannot operate, which leaves the fan circuit operational.  If the fan does not turn on with that wire pulled and when the key is on, then that circuit is broken somewhere, or the fan motor is defective.

Just because a relay clicks doesn't mean it's contacts are good.

Pull the fan connector.  Pull the temperature switch connector.  Check the yellow fan wire, should be 12 volts with key on.  If no voltage then there are either bad connector contacts or a blown fuse or damaged wire.  Fuse is under the dash, 20 amp for n/a manual or 25 for auto or xr2.  (I've never understood why the fuse is different for those configurations, is the fan different or what???  Anybody know?).  Of course if the fuse is bad and blows again, that fan would probably need replacing.

Check the yellow / green fan wire, should be 0 ohms to ground with temperature switch wire pulled.  If not then you've got a bad connector contact or a bad cooling fan relay or a damaged wire or a bad ground connection.  If not 0 ohms then pull the relay connector (left front of engine compartment, white connector, 4 wires), check the black wire, should be 0 ohms to ground.  These last 2 paragraphs should zero you in on the fault.

25 amps is somewhat excessive for the fan motor, but check the circuit first.  Sometimes weak connections can open up under high current demands.  That means a fan pulling a little too much current along with a weak ground or connection somewhere can make the circuit open up under load, but then seem ok with a meter with no load.  If the circuit all checks out ok with the meter, then you will need to carefully inspect each connector contact, each wire at the crimp to the connector (blue or green or white stuff is corrosion), grounds (one is on the driver side, inner fender, near the main relay/coolant reservoir, 5 wires into that ground),

Bypassing the circuit has risks.  The electronic load module monitors the fan on/off condition.  If it does not know when the fan is on, it cannot compensate for the increased alternator load and then increase engine rpms.  I've never tried this, but sounds like the idle would be really low or the engine would stall...Chris

PS... Anyone who gains something from this site, contribute $$ if you can, the man is doing a good job for us here...

[91xr2forfun]

You are correct that is a Green w/red stripe. The relay is actually clicked on until you break the circuit and that allows the fan to come on. Effectively I tested the switch when I unplugged it. That’s not the problem. The fan is working because it was tested separately too. Fuses tested ok under dash.All ok.
I bench tested the fan relay and the ac relay. I did supply 12 v power and hear the clicking, but I also tested the other two pins for continuity. They read close or on 0 ohms. That seems in order.
I tested the wires on the connector to the fan relay with key on and the y wire showed 12.5 v, the yellow/greenstripe showed just 7.7 volts and the other two tested neutral.

I unplugged the fan and checked the yellow wire at the connector coming to it. It showed 0 v. with key on, but the yellow with green stripe showed 12.17 volts. The wires that connect from these to the fan are actually blue and black. That made me think that the + blue was somehow tied into the AC power.
 Also, note that the fan tests for non-AC engines is different that mine. Look at EC11 test in section 27-10-6 of the service manual Fan, Electro-drive cooling.

That’s an excellent point about bypassing the circuit. I’m sure you are right the electronic load would be affected. I will only do that if I get more desperate.

I’ll have to keep thinking. I’ll try to clean up all the grounding straps I see.
I’m still wondering about the ECU sensor that was mentioned in a previous posting and I still want to blame the AC circuit somehow.

In over my head, but not drowned yet. Ha ha. Thank you for your input.

[blueamber]

With the fan switch wire pulled the ac has no effect on this circuit.

That yellow/green wire at the fan has to be ground for the fan to work.  All your tests show no ground there (7.7 volts or 12.5 volts).

Bench testing a relay must show 0 ohms, not close to 0.  ANY resistance present indicates contamination on the contacts, and that relay should be replaced.  That could be why you measured 7.7 volts on that line, resistance in the relay cut the voltage in half.

Pull the cooling fan relay connector and jumper the yellow/green wire to the black wire.  Use a heavy jumper wire, lots of amps will flow if the fan comes on.  It the fan works you have a bad relay.  Leave the jumper in place until you find another relay.

If the fan still does not work, jumper the yellow/green wire directly to the battery negative.  If it works now you have a bad chassis ground on that black wire...Chris

[91xr2forfun]

Thankful that you came up with a plan, but I want to be sure I understand.
 
There are two connectors that I am working with.  When I unplugged the relay  and worked on just the wires (before relay, “upstream?” -) female connector side that comes from wiring harness), with the key on I got the 7.7 volts on the yellow /green stripe and 12.5v on the yellow.

After the relay (“Downstream” ?) is the other connector, it goes to the fan. It’s just connects the blue wire from the fan to the yellow/green (12.17 v. with key on) and the black fan wire to the yellow(0 volts key on).
You want me to jumper the wires that the cooling relay plugs into correct? That will tell me if relay is bad.
If the fan still doesn’t come on, you want me to jumper the same wire (yellow/green) from the same location to the negative terminal of the battery? That will test ground.

Thank you for the diagram and for the info. about the AC. I can forget about that for now.

Sorry to take up so much of your time, but appreciate your patience and want to test it correctly.

[blueamber]

Yes, with the fan plugged in, key on, relay connector unplugged, jumper the yellow/green wire at the unplugged connector to the negative battery terminal.  If the fan works, then you've got either a bad relay, or a bad ground going to the relay.  All the relay does is interrupt the ground to the fan to turn it on or off, so you have bypassed that grounding switch inside the relay.

If this works then try jumpering the yellow/green wire at the unplugged connector to the black wire at the unplugged connector.  This tests that the black wire has a good ground connection.  If the fan works then the relay is not working right.  If this doesn't work, then the black wire is not grounded right and needs repair.

If the jumper to the battery did not work, then the green wire is broke (verify this with 0.0 ohms from the unplugged relay connector to the unplugged fan connector).  If open, then replace the wire or find the break and repair.  If very low ohms but not 0.0, then it's probably corrosion at a connector or corroded wire somewhere, replacing may be in order.

Also spliced into this yellow/green wire is a connection to the electrical load control module, so if the wire needs to be replaced, then that module needs to be wired into the new wire.  If you don't feel comfortable with this part of the job, any good shop should be able to replace the wire for minimal time charge...Chris

[91xr2forfun]

Fan plugged in, key on, relay connector unplugged (& I tried it with fan switch connected and disconnected)              Results:

Yellow/green wire to negative terminal fan did not come on.

Yellow/green wire to Black wire fan did not come on.

It seems the Yellow/green wire is broken or corroded. I will try to verify this tomorrow by using my ohmmeter. Well, so much for an easy fix. The good news is that our weather is cooling down rapidly now and I won’t have to worry about the engine overheating. It’s almost time to focus on getting the snow removal gear ready. Ha ha.
I will attempt to fix the wire and if you can think of any other ideas I would welcome them. Your help has been great and if I need a professional mechanic, I will be able to save him a lot of diagnostic work thanks to you.