algershick

iTrader: (1)

Hopefully this isn't too long to read. Someone wired a toggle switch for my fan into my car using speaker wire. The cooling system wiring still appears intact, so I decided today to run the car and let it get to 225 degrees to see if the fan will actually come on like its supposed to. With the fan toggled on, the temp never gets above 200 which I believe is preventing me from going into closed loop mode.

At 220, I popped the hood to check the fan. My radiator hose was ballooned up right at the thermostat housing. I immediately hit the toggle to begin cooling the car off. I know that my thermostat is opening. Right before 200 degrees I saw the temp dip down. I checked to see if there was oil/water mixing together in both the coolant and engine oil, and they both look good. The radiator cap is a 16 psi and doesn't appear that old, but I'm definitely going to replace it anyway. Is that the correct pressure for an LB9?

I'm going to attach a few pictures; of the hose, the completely screwed up wiring beside my battery, and another of a mysterious gizmo that I was wondering if you could help me identify mounted to the driver side fender.

Any ideas on the cooling issue, or what this doo-dad is? Also, on that wiring photo, notice the hot purple wire with no tape on the end looped through a hole in the overflow reservoir and tied to speaker wire. Nice, huh?

LsxMatt

iTrader: (4)

Hose is bad, just needs to be replaced. As for the fan issue check to see if the relay is intact. It should be on the drivers side firewall, next to the brake booster. Also try replacing the fan temp sensor if you haven't already. The PO of my car did the same thing, except they cut the fan off from the harness, and ran it directly to the battery with a switch. I hooked it back up to the factory wiring, replaced the fan relay and temp sensor, and everything worked good.

Ronnie Brennan

I did what mgg said his was on my 87. I ran mine from a hot wire from the fuse box under the dash and rug up a toggle switch. Only reason why I did this was so that if I had been driving the car hard I could leave the fan running for a few mins after shutting the car off to help cool it down..

algershick

iTrader: (1)

I appreciate the replies, I ordered the hose from the local parts store and it should be here tomorrow morning. I'm going to replace the thermostat, temp sensor, and radiator cap as well. I'll try to check the relay this weekend to make sure its functioning. As far as its placement, you're sure that its on the firewall? I looked at the diagram for my car and I have a relay with all of the same color wires as on the diagram between the battery and radiator.


Also, any ideas on what that thing is in my 3rd photo? The black **** on top is adjustable.

algershick

iTrader: (1)

Here is a pic from my 1986 service manual of fan wiring for Vin F cars.

I know you guys are telling me that there should be a fan switch in the passenger side head, but I'm not seeing it in the car or on the diagram! The pressure switch noted is for A/C isn't it?

I'm checking continuity of wires in this schematic and so far everything appears to be wired correctly. The fuse is good. I replaced the relay and the coolant temp sensor.

Even though this isn't the correct forum for this, I discovered what that silver box is from the 3rd pic in my original post. There are a number of wires shoved through a drilled hole in the firewall that are then cut right before this silver thing. It had a heavy gauge orange wire spliced into the side-marker of all things, and then a blue wire still connected through the firewall. I googled the manufacturer's name and part number from the back-- its some cheap-o security system "impact movement sensor". I'm getting frustrated with the wiring I keep finding from the previous owners.

Sick92

Just re-iterating that that hose NEEDS to be replaced, do not pop the hood EVER AGAIN when the car is warmed up, you'll chance getting 3rd degree burns if that pops. It happened to someone I knew...not a great thing to live with for the rest of your life.

algershick

iTrader: (1)

Thanks for the concern, I agree completely about staying clear of a hose in that condition. I already replaced it on Sunday along with the thermostat and coolant temp sensor.

Sick92

No problem, it's sometimes too easy to forget sometimes how dangerous some of the stuff under the hood of our cars is when you are so used to working on/seeing everything all the time. Glad to hear it was replaced, any cooling problems?

algershick

iTrader: (1)

The problem still remains that my cooling fan won't turn on, on its own! Its got a toggle wired to it that does function. From what I can see, all of the wiring is intact. The only thing I'm not able to check is that the green/white wire from the relay is indeed plugged into the ECM.

Sick92

Your car might be different, but when my cooling fan wouldn't turn on, I found out that it was my cooling fan switch on the passenger side head. One wire went to it, replaced it for like $10, and everything worked. The dumbass PO hardwired it prior to that, all because of a $10 part.

algershick

iTrader: (1)

That's why I posted the wiring diagram for my year and vin, I don't SEE a fan switch on the diagram at all. I can't feel anything between cylinders 6 and 8, and there is no loose or cut green wire on the passenger side at all.

Can someone with knowledge of 86 TPI wiring chime in and help me clear this up?

Sick92

You by chance check the operation of the relay?

You need to take it out, manually jump 85/86 terminals with b+/-. Once you do that, you should feel/hear a distinctive "CLICK". If not, relay is most likely bad.

Continuing
Then take an ohmmeter connect to pins 30/87 and make sure it reads 0.00-0.5ohms and not open/fault.

I'm sorry I didn't see your diagram, that looks like a cooling fan pressure switch, not for your A/C. Apparently it should be screwed into your radiator and look something like this.

algershick

iTrader: (1)

The diagram says that the switch opens at 233 psi, on the radiator?

I'll check out the relay tomorrow.

Sick92

Yeah that's true, wasn't thinking, radiator would blow up lol. Check your radiator for kicks, I've seen diagrams that have been wrong before and from this website it says they are located in the radiator.

Sick92

Also I didn't know what type of fuel delivery your car uses (4bbl or fi), but I entered FI just for kicks, and found this in alldata:


Worth checking out, it controls the fan

Sick92

Also here's the specs for the sensor/switch. You basically take an ohmmeter to both pins of it. At the listed temps, it should be around that amount of ohms.