Electrical Gremlin: A/C and Radiator Fan

Ray · Post by **Ray** » Tue Nov 11, 2008 12:36 pm

looked at my car today and saw no relays under the hood. fan harness follows the frame rail then goes thru the firewall. the relays are either in the fuse box under the hood or in the car.

Post by **hEaT** » Tue Nov 11, 2008 12:37 pm

demonfire wrote:Joe,

Why dont we just cut the wiring to the fans and isolate them via a relay that we could locate in a place that we can find? it wouldn't be hard to do and relays are cheap. I have a whole crapload of ford relays from my parts focus.

I was thinking the same thing. I'd rather find the problem and fix it than bypass it. If not, we can do the separate relay.

demonfire wrote:looked at my car today and saw no relays under the hood. fan harness follows the frame rail then goes thru the firewall. the relays are either in the fuse box under the hood or in the car.

Thanks Ray. I'll check in the car and see if I can find anything. Maybe there are located under the fusebox?

Post by **DPDISXR4Ti** » Tue Nov 11, 2008 12:39 pm

Does nobody have the '85 electrical troubleshooting manual?

Post by **hEaT** » Tue Nov 11, 2008 12:43 pm

DPDISXR4Ti wrote:Does nobody have the '85 electrical troubleshooting manual?

If no one does, I'll grab one.

http://cgi.ebay.com/ebaymotors/1985-For ... Literature

Scalawagk9 · Post by **Scalawagk9** » Wed Nov 12, 2008 7:15 pm

Don't know if this is helpful...but...on my 1985 XR4Ti the main radiator cooling fan relay is relay position 8 in the fuse box. My 1985 EVTM manual, on Page 15, says position 8 is the stop lamp relay. Page 42, regarding "stoplamp" troubleshooting also says position 8 is the stoplamp relay. On my car, I found the actual stoplamp relay next to on the left side of the steering column above the brake pedal.

Post by **hEaT** » Wed Nov 12, 2008 10:59 pm

Very helpful, thank you.

Could you check on page 93 and see what it says in regards to the A/C Condenser Cooling Fan Relay and Engine Cooling Fan Relay component location?

Thanks!

Scalawagk9 · Post by **Scalawagk9** » Wed Nov 12, 2008 11:40 pm

Re: 1985 EVTM---

Page 93 is in vacuum section.

Page 91 is the text page for the schematic on page 90, labeled "A/C-HEATER/COOLING FAN"

Relays:
"A/C Compressor Clutch Relay" located "in fuse box"
"A/C Condenser Cooling Fan Relay" located "in fuse box"
"Engine Cooling Fan Relay" has no description of location. It is blank.

Fuse Box:
Position 1 is "A/C Temp Switch"
Position 3 is "A/C clutch W.D.T. Cutout"
No mention of "Engine Fan Relay"; however as I said, mine was found to be at position 8 which the EVTM says is "Stoplamps"

Post by **hEaT** » Wed Nov 12, 2008 11:44 pm

Great help. Thank you. I'll have to look at it this weekend.

Post by **DPDISXR4Ti** » Thu Nov 13, 2008 2:01 pm

Scalawagk9 wrote:Relays:
"A/C Compressor Clutch Relay" located "in fuse box"
"A/C Condenser Cooling Fan Relay" located "in fuse box"
"Engine Cooling Fan Relay" has no description of location. It is blank.

I recall now that there are two different fuse box covers - really, it's only the graphic on the bottom side that changed. I guess the relay relocation was the reason for the change.

I guess this will be one more thing we'll have to document and add to the list of "changes by date".

Post by **Ed Lijewski** » Thu Nov 13, 2008 2:30 pm

Joe:

Your pic showing the two electrical connectors--those connectors would appear to be the power source for the two fans--can you follow them to see where they merge into relays?

YMMV

Post by **hEaT** » Thu Nov 13, 2008 4:38 pm

Ed Lijewski wrote:Joe:

Your pic showing the two electrical connectors--those connectors would appear to be the power source for the two fans--can you follow them to see where they merge into relays?

YMMV

I tried and couldn't see anything. Ray looked on his 85 as well and followed them right into the firewall with no relays in line.

Ray · Post by **Ray** » Fri Nov 14, 2008 7:51 am

Yeah, there are no relays in line before the firewall. The two fan supply lines go into the main bundle of wire along the drivers side frame rail.

Post by **hEaT** » Sun Nov 16, 2008 8:22 pm

I can confirm the #8 position relay on my car is in fact the radiator fan relay. I swapped with a known good relay and the fan still turns on. With that relay out, the radiator fan doesn't turn on at all, even with the A/C switch on, but the A/C fan will turn on as soon as the ignition is on.

I'll check continuity on the fan temp switching wiring and see if that is shorted out.

Ray · Post by **Ray** » Mon Nov 17, 2008 8:50 am

yeah it just sounds like X feed wire is always on (or rather, with key on). easy enough to isolate.

Post by **hEaT** » Mon Nov 17, 2008 10:32 am

demonfire wrote:yeah it just sounds like X feed wire is always on (or rather, with key on). easy enough to isolate.

One would think. My car was built in 12/84. Must been been Weihnachten or Neues Jahr when they were wiring this thing. It's a rats nest