Well the AC quit on a hot week here in Pittsburgh. This is our second X300 and I am quite familiar with the car. However, I can't figure out whats up with the AC. Hooked up the gauges and gas was low. Shot some in and compressor kicked in nicely. High side got up past 250 and the condenser fan should have kicked in. No joy. Still hot air. Did a self test on the AC and got codes 20, 21, 22, 23, 24, 25, 26, 27. Looked at TSB 14-04 regarding MY 1995 which this is and checked fuses F11 and F17 in engine compartment for fan relays which were good. Jumped the wires at single pressure switch as per TSB. Nothing. Can anyone help?

Thanks,
Ruben Velez

 

If you never slow down below about 40 MPH then you don't need RAD fans. You will have enough airflow through the condenser. (Only use the A/C when going FAST!!)

Did your car have the cooling fan switch modification???

You need to look at the electrical guide and diagnose.

bob gauff

 

Thanks for the response. I didn't see any evidence that there was a modification. Where do I look? I am suspecting the fan relay went bad since after jumping the single pressure switch, the fans still don't work. When the engine got up to temp only the lower fan kicked in at high speed. Where is the fan relay located?

 

The upper fan might be 'toast'. You need to ensure that the fuse for that fan is good and the fan ACTUALLY works before condemning the fan controller.

The fan controller is more than a simple relay. It is located under the left headlamp assy. (under the car).

The pressure switch modification is described in one of the TSBs.

bob gauff

 

Good point. I will check the fans first. Has the fan controller ever been known to fail? So, I checked out theTSB on the single switch modification and it's basically put a jumper wire on the connector at the harness side. I did that already and nothing. according to the TSB if the switch was faulty it may have fried the fan relay. I guess that needs testing too. First the fans.

 

OK, I finally had time to take the fan assembly out of the car and bench test it. Both the fans work strong, however I suspect the right upper one may need new bearings soon. I reinstalled the fans in the car, took it out for a spin and the left one kicked in when the engine was warm and the right one nothing. Then I made sure there was the proper jumper in the single switch circuit and grounded the white and blue wire at the trinary switch which should turn on the fans for the condenser. Again, only the left one kicked in, on high. I am not sure when the low speed is supposed to work, however I understand the two fans work in series to slow them both down. If the right fan is suspect, would the circuit resort only to only the left fan kicking in on high. Is there a place where we can buy a new fan motor with out paying through the nose? Anyone know what brand these fans are? Model number perhaps. The fan relay as also still suspect.

 

The fuse for the right fan might be 'blown'.

I remember getting sales fliers from BPI (Motorcars LTD.) about the availabilty of individual fans (not the assy).

check them out??

bob gauff

 

Hi italcarnut,

I would suggest you try lubricating the bushings in the fan to see if its performance improves. Try a good light machine oil like 3-in-1 oil, etc. WD40 may help free any corrosion, but it doesn't leave much lubrication behind.

I can't tell you where to find new fans or motors, but eBay is a good place to look for good working salvaged fans. The fans and fan cowl are identical for the '93-'94 XJ40, X300 and X308. I put X308 fans in our '93 XJ40. You might look for some good used late X308 fans to get the "newest" parts you can find.

Cheers,

Don

 

Thanks Bob and Don. I will check these out. Yes, the first thing I did was check the fuses, great shape.

 

The fuses are 30 amp and I have several motors that draw WAY over that and blow fuses. I removed them from the cowls and replaced them with motors that draw around 25 amps. When I worked at the dealer, the only way to get a replacement motor was the ENTIRE fan assy.

I saved maybe about 10 fan cowl assys. and salvaged the good motors from them.

I measured the current draw from the ones that blew fuses and found them to draw too much even though they still ran.

Just because the fan runs does not mean it is good. Lubing might help but I would check how many amps it is drawing to be sure.

bob gauff

 

What a good point! I have a multimeter. How do you check current draw?

 

You would connect your meter inline with one of the wires ( doesn't matter which, just got the polarity right on your meter) and leave the other connected. Be aware of the current rating of your meter, most max out at 10 amps and the fan can draw more.

You can get clamp meters, but I think those only work on AC circuits not DC.

 

I have a meter that has inductive pick-up (it clamps around one of the wires) and it is selectable between AC or DC.

It will read 200 AMPS or 400 AMPS with a HOLD feature to read the last MAX reading.

These type of meters are safer than 'inline' type meters because they don't actually handle the current.

You could 'rig-up' your own test with a smaller rated fuse like a 20 amp and see if the fan motor will operate with it the circuit for a while without overheating the wires or fuse.

A meter is the best way to actually measure but there are other ways to test the limits of devices.

bob gauff

 

It looks like I have to replace both. I thought I was going to get away with a recharge but the compressor is gone. Anyone know if there is a Ford equivalent for either part?