cooling and fan issues

[yahrt]

1. Running a BP 437 with the Sniper EFI, light blue wire from the EFI harness connected to a green fan wire, I am spliced into that same green wire leading to an override switch that connects to a ground. The override switch turns the fan on but the sniper does not. Fans #1 and 2 in the ECU are set to activate at 190 and turn off at 180. At wits end.

2. Out of the blue, while working on the first problem, I started dumping coolant out of the radiator fill cap. Why would that happen? Got me to start questioning the plumbing on my Canton tank. 168783 Does this look correct? Or should the tube connect to the top rather than the bottom. And is the height of the tank relative to the radiator hose fill cap important?

As always all ideas/advise appreciated. I am slowing learning.... Thanks TY

[yahrt]

I had typo, BP 347, and the radiator cap is 20#

[Norm B]

The Canton tank needs to be vented to the atmosphere. I took a screenshot of your picture. The port circled in red should have an elbow in it with a tube extending down. This will allow coolant to enter the tank from the fill port without pressurizing the tank. The way you have it now, you have defeated the pressure relief of your rad cap and could be seriously over pressurizing your system.

What ECT is the Sniper showing and does it match your gauge? Where do you have the temp sensor for the Sniper installed?


HTH

Norm

[Jhinkemeyer]

What does the coolant temp on the Sniper handheld read, I assume it is crossing over your 190 threshold. Does the Fan 1 indicator say "On"? Is the blue wire going to ground when that occurs?

[yahrt]

I now have the Canton tank vented properly. Upon startup the temperature started rising and coolant started leaking from the rad cap again, the Sniper had a temp of 185 but I had to shut down prior to seeing if the Fan kicked on. Has my cap gone bad? Thermostat?

[yahrt]

I'll be damned....I am using the Boig pipes and came across another post by RJD with the same issue, turns out there was a little ceramic ball blocking the port. Took mine apart and low and behold there was a little ceramic ball blocking the port! Unfortunately, in my effort to jar it loose (packed in pretty tight) it went back into the system...

[yahrt]

OK, so no more leaking from the cap, but temp on in the Sniper handheld went to 192 and it says fan #1 and #2 are on but it is not running, override switch turns it on. Other thoughts?

[Norm B]

As you know the Sniper is supposed to supply a ground signal for the fan relay to turn on the fan at the selected temp. Try disconnecting the Sniper wire, then with the key on momentarily ground the green wire. The fan should start.

[yahrt]

Yes, grounding the green wire #1 or #2 will start the fan.

[Norm B]

What fuel pump wiring did you use? There are two blue wires that come out of the Sniper. One heavier gauge that comes from the 7 pin connector for fuel pump power and one lighter gauge that comes from the 10 pin connector for fan activation. Any chance you mixed these up?

If not then check all the connections at the Sniper. Set the fan on temp on both fan 1&2 as low as you can on the handheld and warm the engine above that temp. Check for continuity to ground on both of those circuits at the Sniper.
No continuity to ground means failure of the Sniper unit is about the only option left.

HTH

Norm

[Jhinkemeyer]

Well then you need to verify that the blue wire is actually going to ground, sure sounds like it is not.

You are for sure using the Light Blue wire from the 10 Pin connector correct (not the dark blue from the 8 pin).

I'd say get it up to temp and check continuity from your known good ground (at your override switch) to the blue wire. Or check for 12V from bat+ to the light blue wire when the fan is indicating "on".

Might be worth lowering the switching temp just for testing so you don't have to wait for it to warm up for as long to do the diagnosis.

Was the sniper harness messed with at all? Lots of people de-pin unneeded circuits, or maybe an issue for the factory. Is the light blue wire at pin location "C" per the manual?

Since it sounds like you have set it up for 2 fans (not sure why if using the supplied fan?) can you try using the light green wire (fan#2 pin D) and see if that works? You only should need one fan setup in the sniper unless you're doing something custom I missed.

[yahrt]

Ding ding, ding, we have a winner and a loser! Jhinkmeyer is the winner for his diagnosis, Norm gets honorable mention for his helpful suggestion. The sniper harness was messed up. I remember de-pinning the unused wires, I sure don't remember un-pinning and re-pinning the others. The three remaining wires were on the wrong side of the harness. All is good but I am the loser. This forum always reminds of medical grand rounds at work where a doc presents an interesting case and the audience starts making differential diagnoses. It has yet to let me down. Thanks as always for the help.

[Jhinkemeyer]

Ding ding, ding, we have a winner and a loser! Jhinkmeyer is the winner for his diagnosis, Norm gets honorable mention for his helpful suggestion. The sniper harness was messed up. I remember de-pinning the unused wires, I sure don't remember un-pinning and re-pinning the others. The three remaining wires were on the wrong side of the harness. All is good but I am the loser. This forum always reminds of medical grand rounds at work where a doc presents an interesting case and the audience starts making differential diagnoses. It has yet to let me down. Thanks as always for the help.

Excellent, glad you got it sorted!

[RJD]

I'll be damned....I am using the Boig pipes and came across another post by RJD with the same issue, turns out there was a little ceramic ball blocking the port. Took mine apart and low and behold there was a little ceramic ball blocking the port! Unfortunately, in my effort to jar it loose (packed in pretty tight) it went back into the system...

I almost suggested you check to see if you had the same issue I had, but thought, what are the odds? Pretty good it turns out.

[Norm B]

Glad you found it.