SPF Electricals -

Blas · #1 (**permalink**) 12-18-2008, 06:54 PM

OK – winter is in full swing and I’m getting restless…
So lets here about some electrical gremlins or oddities on your SPF…
Maybe someone has an electrical modification they have been thinking about doing…Now’s the time…I’m in the mood to do some detective work…

flipscobra · #2 (**permalink**) 12-18-2008, 08:44 PM

I have 1, my amp metter keeps jumping unless you cut the lights on an the fan. the parking lights pulse when they are on. Its charging but annoying watching the hand jump all the time.

greg schroeder · #3 (**permalink**) 12-30-2008, 09:23 AM

Quote:

Originally Posted by flipscobra

I have 1, my amp metter keeps jumping unless you cut the lights on an the fan. the parking lights pulse when they are on. Its charging but annoying watching the hand jump all the time.

I'm not an any sort of expert, but here's what I figured out.

For my car the wire for the amp meter ran a very long length from the one wire alternator then across the front of the car, then down the left fender and then to the fuse area, then to the amp meter, then out the other terminal on the amp meter and then to the battery in a round about way. The length of wire and gauge size was insufficient for higher amp draws, so things tick a bit on the gauge when accessories are used. The amp draw isn't really huge as there are minimal accessories, so it didn't seem to cause any function problem other than a gauge tick when things turn on and off for an instant.

In addition for my car one of the spade connector wires on the amp gauge was loose, resting in location to touch and jiggle on vibrations and bums. The gauge is in series, so it makes an intermittent loss of connection causing a jiggle in the reading. In my example the car was a one wire alternator, so for the time the wire is not touching the alternator tried to send massive voltage to charge. It melted the internal regulator in the alternator. I put on a new alternator and plugged the amp wire on tight. It was good to go and just fine.

Another condition is if the one wire to the alternator is loose or falls off the alternator. That also causes the amp meter to do strange things. Fix that quick or you'll be in trouble.

DON BEVERS · #4 (**permalink**) 01-04-2009, 02:12 PM

I want to apologize for the delay of my response, I didn't realize that these threads could have more than one page. Dumb yes, if you don't know, you don't know.
Ok, first thanks for all of the responses and info.
Blas, of course you gave the necessary first things to check, but all of these issues were my first thoughts also.
So I pulled the 6-pin connector off and got the no. 4-pin out first. In the course of trying to get the no. 3-pin out, that 4-pin fell onto the floor. The wire to it was only 2.5in long! A wht w/blk stripe wire. I moved the 3 wire, a red w/blue stripe into the 4th location and started the motor. The tach still works, but because it is raining right now, I won't be able to drive it for awhile. I don't really want to rev it to 3 or beyond with cold oil.
Why is the tack designed this way and what did I accomplish by moving these wires around? Does it have something to do with the digital 6a?

Blas · #5 (**permalink**) 01-04-2009, 02:47 PM

They normally cut that white with black stripe wire in the cars loom and reuse it to connect to the MDS6AL.
See "Tach1" in my gallery photos (from my wiring diagrams)

SPF2245 · #6 (**permalink**) 12-18-2008, 11:24 PM

I had a bad short which caused the starter, lights and such all work in tandom. Ended up being a bad light bulb of all things. But in the adventure to track it down, I pulled the wiring down under the dash and to tell you the truth, my six year old could have done a better job. There was pinched wires due to the zip ties being clamped down to about 6,000ft.lbs, others were bent to the breaking point. So, I spent a few hours re-doing it for the simple hope to stop future problems.

Goopie 18 · #7 (**permalink**) 12-19-2008, 06:42 AM

One of my cooling fans keeps blowing the 20 amp fuse. This happens only while driving the car. I have the extra manual fan switch set up. Replaced the relay to no avail. Then I noticed that the fan was turning the wrong way. Switched the wires, now it turns the proper way. I pulled the fuse. One fan does a great job by itself. I'm afraid to put the fuse back in. Don't want a fire. Is it possible that the fan turning the wrong way while driving at speed would cause a fuse to blow?

Blas · #8 (**permalink**) 12-19-2008, 08:32 AM

Goopie_18
I have seen this once before.
Check the connections at the 2 relays on your drop down fuse panel - are they all tight? Does the wiring looks ok?
Check the wiring connections at the 2 fans, and on the temp switch (lower left side of the radiator - it's just a ground)
A loose wire or bad crimp can cause havoc with these fuses.
I would now suggest you reconnect the fuse - after the wiring inspection and fixing the fan rotation and see if it still pops a fuse.
The fuses will protect the fan circuits.
Now the fun begins:
If it still blows the fuse, the next step would be to switch the relays on the fuse panel and see what happens.
If it then blows the other circuit you know the problem is in the relay - replace it.
If the same fuse blows, you know the relays are both ok, and have narrowed it to wiring in that circuit or that fan motor.
BTW: Which way is the good fan moving the air? They both should pull air into the engine compartment.
So now remove the power supply wires from both fans and use temporary jumpers to switch the power supplies to them.
Retest and see what happens. If the same fuse blows it's the wiring, if the other fuse blows, it's the motor.
Hope this makes sence, you are just switching power flows to find a bad component - a process of elimination.
Send me a message to my email address listed below and I'll send you my home number to call.
Let me know what the result is.

Blas · #9 (**permalink**) 12-19-2008, 10:05 AM

flipscobra
Tell me this:
First - So I can determine how your AMP gauge is wired - What is your SPF car #?
Which way is the needle jumping? + or - ?
Now:
Car running - no lights or fans - what is the meter doing?
Car running - lights on - no fans - what is the meter doing?
Car running - lights on - fans on - what is the meter doing?
Check the wire connections on the back of the AMP meter visually - look clean & secure?
Check the wire connections on the starter solenoid on the firewall (that's the power source for the AMP meter) - look clean & secure?
Check the wire connections on the alternator - look tight, clean & secure?
REMEMBER - We are talking wiring that is always "HOT" so do your inspect ions with CAUTION.
Send me a message to my email address listed below and I'll send you my home number to call.
Let me know what the result is.

Blas · #10 (**permalink**) 12-19-2008, 10:18 AM

cobras
Both of the Superformance fans should be "pulling" air into the engine compartment.

cobras · #11 (**permalink**) 12-19-2008, 09:30 AM

Quote:

Originally Posted by Goopie 18

One of my cooling fans keeps blowing the 20 amp fuse. This happens only while driving the car. I have the extra manual fan switch set up. Replaced the relay to no avail. Then I noticed that the fan was turning the wrong way. Switched the wires, now it turns the proper way. I pulled the fuse. One fan does a great job by itself. I'm afraid to put the fuse back in. Don't want a fire. Is it possible that the fan turning the wrong way while driving at speed would cause a fuse to blow?

what dir should the fan be going? should it be pushing the air towards the rad, or pulling the air through the rad,

CJ428CJ · #12 (**permalink**) 12-19-2008, 10:26 AM

Goopie 18,

Having the fan wired backwards so it blows the wrong way could certainly cause the fuse to blow while driving at speed. Motors have a huge in-rush current. Depending upon the motor it can be up to 6 times the normal full load current. While driving at speed, the motor is trying to turn one direction while the air rushing across the fan blades would be trying to turn it the opposite direction. That's going to significantly increase the current that the motor draws as it fights to try and turn the "right" direction. The result will be significantly higher current draw until the fuse blows.

Chris

Blas · #13 (**permalink**) 12-19-2008, 10:38 AM

Right - The fans will turn when the car is moving from the air coming thru the radiator. They will actually create a small current flow, and if one is wired backwards could pop the fuse.

Goopie 18 · #14 (**permalink**) 12-19-2008, 03:43 PM

CJ428CJ and Blas: my thoughts exactly. I suspect the cause might be the reversed fan. I check it out this weekend. If not, I'll follow Blas's steps. Thanks guys!

STL Mark · #15 (**permalink**) 12-19-2008, 03:53 PM

I noticed that my anmeter jumps. So, at idle it's steady and reads just on the positive side. But at highway speeds (and only at highway speeds) it has a rythemic bounce in the positive. Normal?
No performance symptoms - is it a short? Loose belt? A symptom of something else?

Blas · #16 (**permalink**) 12-19-2008, 05:21 PM

Goopie:
A cold beer says it's the reversed fan...hahahaha

PANAVIA · #17 (**permalink**) 12-21-2008, 02:02 AM

Don , I am assuming this is the Smiths Repro tach.

Question ; Does the tachometer track at other RPMs >? (idle -3000 )

I am wondering if you are having AC voltage feedback at high revs with the Alternator.

my other idea would be the tach feeding off of the same positive circuit as the MSD.

Do you have a another tach that you can test with >?

Bill Wells · #18 (**permalink**) 12-22-2008, 04:09 AM

Dan Bevers ---------- years ago when I switched my old Ford ignition systsem to MSD, my tach did the same thing -----went up to 3k and then to zero while engine revs were still going up .

My mechanic called the MSD hot line tech support guys and we were told to add a MSD Tach Adapter ( I can't recall the MSD part number at the moment , #8910 comes to mind but i will continue to look thru records) .......a diode also had to be added after the Tach Adapter to smooth the tach out.

I recall in other experiences such as mine discussed some time ago that some folks with newer SPF's
had slightly different tach wiring and different alternator wiring which also affected Smith tachs differently on newer cars vs older cars like mine . Blas is the expert on what/when electrically . Bill

Bill

Goopie 18 · #19 (**permalink**) 12-22-2008, 06:55 AM

CJ428CJ and Blas seem to be correct. After correcting fan rotation and a 50 mile test drive, the fuse did not blow! I'll keep an eye on it but it looks like I'm good to go. Thanks guys!

Blas · #20 (**permalink**) 12-22-2008, 08:42 AM

Dan..
The newer tachs do not need a tach adapter. Yours is the newest style based on your car number. I remember reading about a problem someone had similar to this once before. I'm sure the the MSD tech people can help you out on this one, or Dennis Olthoff. Is this a Roush engine? they would also be a good resource. Check the easy items I mentioned and then follow up with these resources. And remember to post what you've learned here on CC. Just to be sure here, your tach signal to the MSD is coming from the "black/white" wiring on the back of the tach loom right? You have a small "red" power supply going to the ignition switch. Then the big "red" and the big "black' as mentioned earlier.