When it rains it pours Coyote will not start

[cfriedman67]

A quick background. Coyote Gen3 TKO 600 Ron Francis harness, Vintage gauges. Just NY state registered/titled etc.. 2 weeks ago. While driving last week about 50 miles or so I had a clutch issue that I noted on the forum and seems to be fixed. While driving before the clutch issue I blew the same fuse twice. I believe it is the gauges/radio fuse. (10 AMP) I also have my seat heaters on that fuse but I don't have a radio on that fuse. When I went to start the car the other day it was dead. Lights did not work, fuel pump did not prime etc... I checked the battery with a multimeter and it read 12.6 volts. Electrical is not my strong suit. Any thoughts on what the issue could be and more importantly what and how to trouble shoot.

Thanks Craig

[nuhale]

You have to think of the RF harness and the coyote controller as 2 separate systems that only come together at few points. These include ignition, fuel and clutch safety. What you describe above seem to point to a ground issue. Also don't know what seat heaters you are using but that circuit may not be enough to handle the load. I don't recall if the pump and radio are on same bus line.

[cfriedman67]

I Have Cobraheat seat heaters. I can check to see if I need a larger fuse and will also check the grounds over the weekend. One thing I forgot to mention is when I went to start the car and it was "dead" I also pulled out the light switch to check it but no lights. A few minutes later when I was standing there the headlights came on as I forgot to push the light switch back in. I then went to start the car again but got nothing and the lights went off again. Not sure if that helps but I guess the more info the better.

Thank you

[nuhale]

Check the 150amp master fuse.

Be careful. Just putting a bigger fuse is NOT the solution. The circuit is designed for that amp (wire gauge, distance etc).

[egchewy79]

I also have the cobra heat seat heaters wired to my 10a wiper circuit. I did have to replace the fuse once but hasn't blown again since then. I then had an issue w/ a parasitic draw a few weeks ago that I haven't been able to replicate that I assumed was related to the replacement of this fuse. since recharging the battery, things have run fine. This shouldn't affect your starter assuming you have 12.6v at the battery.

[cfriedman67]

where is the 150 AMP master fuse? Is it in the fuse panel? Found it.

[Al_C]

I would rule out the coyote harness itself as the source of your problem. If the lights are going on and off on their own, that would seem like an overall ground issue or a loose wire someplace. I would suspect the connections that provide power to the RF fusebox as well as to the coyote harness. Maybe you have a loose connection around a master cutoff, or on whatever you're using as a bus to provide power to both? But then again, what do I know - I wouldn't classify myself as an electrical expert either.

How to troubleshoot? My idea is that a)disconnect the battery, b) check for continuity on the lines between the battery and the fusebox. If you have continuity, then it is probably a ground issue. If you don't have continuity, then you've got a bad connection someplace. You can do the same thing with the coyote harness. Continuity from various connections to the PCM should tell you whether bad connection or ground.

[GTBradley]

I totally agree with Al, it’s got to be a grounding issue and good electrician/electronics tech will always start at the source and work their way in. I’d put money on the neg cable at the battery being loose. Then again, I’m not a very good gambler.

[sread]

If you don't find a loose connection , don't rule out the battery. It seems to be a fairly common failure mode now days - voltage checks fine, but as soon as you put any kind of load on it - nothing. Caused by a break in one of the internal connectors. Very easy to verify if you have another known good battery.

[Railroad]

Sounds like a cheap master disconnect switch going bad. If you have one, switch it on and off with the headlights on and see what you get. Good luck,

[cfriedman67]

So I’ve checked the battery connections and they are solid. I’ve also checked the grounds. Battery to engine and engine to frame and they are solid. Checked master fuse with multimeter and it’s good. What should I check next?

[Rdone585]

IF you have a clutch safety switch, check to make sure that it isn't disabling the ignition circuit.

[cfriedman67]

If that was the case I’m assuming that wouldn’t stop the lights in the car from working or the fuel pump to prime when I turn the key? That is what i have going on currently no lights, fuel pump priming etc…

[Rdone585]

There is also a neutral safety switch in the harness schematic. Perhaps that isn't at the proper power level and needs attention.
I have had to fiddle with the battery disconnect key many times. Once I had to bypass the battery cut off switch. Are you sure you have power on both sides of the switch. Use a handheld voltmeter or power test light to test power levels from the battery all the way to the fuse panel. There has to be a point where the power is disabled from getting enabled to the other parts of the circuit.

[cfriedman67]

Thanks. I’m starting to think it’s a bad battery as Sread said above. Although the multimeter said 12.6 I attached a charger to the battery and it’s been charging for over four hours and still says charging. Might get a new battery and try that.

[jiriza84641]

1. battery has12.6 v=good
2. check master disconnect for voltage while disconnected, and check for voltage while engaged.
3. engage battery disconnect and check voltage at the RF harness.
4. I would not use the radio wire for the cobra seat heater. if you do not have a heater then use the brown heater wire to power the seat heaters.
5. double check all your grounds and verify they are snug and making contact to metal, scrape off some of the powder coat to ensure.

6. give me a call if you still having issues ill see if I can help, 773- 896- three three five five.

[Alan_C]

Connect a voltmeter to your battery and have a friend watch the voltage drop when cranking. If the voltage drop is excessive, battery is toast. I would expect no more than a 2 volt drop while cranking with a good battery, but just a WAG.
Ford Performance has noted that they do not recommend having the battery more than 10 feet from the starter/PCM. Not an issue when care is taken with the positive cable wiring. This is likely due to the voltage drop seen by the PCM.
Where is your battery mounted? What size positive cable are you running to the starter? Do you have a positive cable direct run from the battery to the PCM or are you connecting to the starter first. All of these choices can affect the voltage seen by the PCM when cranking. Also a large gauge ground cable from the block to the frame is needed. An adequate return path for the current is just as important as the positive side.

[Al_C]

Haven't looked at this in a bit, but just came up with an idea... Sometimes wires get crossed. (Gee, I don't know how that could happen!) That circuit that kept blowing fuses - are the wires connected correctly? It's related to grounds, and who knows, that could even be draining your battery. I know I had a problem where my headlights were cross-wired and it took a fair amount of time to find that. Worth checking those circuits where you have concerns.

[cfriedman67]

Don't ask how but when I took the battery out of the car it charged in an about an hour and the car started right up. I will have some one start the car while I look at the multimeter to see how much the volts drop and decide if the battery is toast. Jiriza84641 suggested the the seat heaters are blowing the fuse because when they are both on high they are pulling more than 10 AMPS. He suggested an alternate way to wire them using a relay which I think I might try. Appreciate everyone's help and advice.

[Rdone585]

When something like this happens, suspect the wiring to the battery, or battery terminal connectors. I still suspect a bad ground connection. After the battery inspect alternator wiring to make sure it is sound. Not sure how old your build is but cables can actually corrode from the inside. Connectors can have corrosion that resists the flow of current even with tight connections. If the insulation looks crusty or you see deposits where the insulation terminates this is a red flag that the wire should be replaced. If the wire is stiffer than the "like new state" then this could indicate corrosion in the wire. Make sure there is no paint, lubricant, sealer, etc. (other than dielectric grease) when connecting circuits together, especially to the frame.