Hi Folks: I recently purchased 29 Ford Coupe hot rod with 350 Chevy crate engine dual electric fans and 700R4 automatic transmission. It was built by one of my friends' father who unfortunately passed away and who built several of these over the years so it is built pretty well (my friend, however, has no interest in or knowledge of cars). It was built in 2010 and has about 4900 miles on it now, I put about 100 miles on it so far (had it about a week) with no issues. The way he wired it is, first turn on battery cut off switch, which turns on fans and electric fuel pump, then turn on ignition and then press starter and off you go. Well, today I wanted to take it for a spin (was sitting only couple of days), turned the battery cut off switch and nada - no fans came on/no electric pump nothing, obviously the ignition and starter did nothing either. There was a blown fuse for one of the electric fans, which I changed, but that did nothing. Thinking battery was dead, I tried to jump start it. While I had my daily running and battery connected to the Ford's battery, I was able to turn the battery cutoff switch on and fans and electric pump came on. When I turned the ignition, all the lights and gauges worked, but pressing the starter did nothing. It would spin once, but it would not start (not enough juice). I tried couple of times and nothing. Then I checked the battery itself, and to my surprise, it was fully charged, so no battery issue. I checked all the connections at the battery and cutoff switch, all good too. I ended up removing the battery cutoff switch, and one of the prongs was kind of loose so I am hoping it is bad switch that needs replacing. I was surprised that when I tried to jump start it, everything came on with exception of actual starting the car. I though if the switch was bad, the extra boost would not help anything (but I am no electrician). I checked all the connections and did not find any loose/disconnected wires. Could it be as simple as bad cut off switch or am I missing something? What else should I check? Any help/input would be appreciated....thank you.
It sounds like you're still low on power. Yank the battery and take it to autozone or Napa, ect. If you tested the battery with a standard multimeter it will only ensure voltage. But its the amperage the battery needs to put out to start. In some cases even a jump start won't help! Otherwise, double double check grounds and connections. Corrosion is deadly! Albert Sent from my SM-G960U using The H.A.M.B. mobile app
Make sure the battery terminals are clean; just because there may be no corrosion showing doesn't mean you have a good connection.
I am aiming at problem being a grounding issue. Check ground cable from engine to chassis. Negative battery cable has to be grounded both to frame and engine, due to the rubber motor mounts. Also car body has to be grounded to frame!
" jumping" a battery is intended to boost a low battery , unless you have really heavy duty set of cables & clamps , they won't start a car with a dead battery .
It really sounds like a bad battery since everything comes on with the jumped battery. However, it could be really bad connections at the battery cables. I didn't see any voltage readings. This is something that would be easy to troubleshoot with a voltmeter.
I'm going with the bad connections theory. Still making sure that your battery is actually up to snuff eliminates that from the list and that should be done first. You should be able to find a resistance in the circuit due to corrosion or a poor connection by checking for a voltage drop in several spots in the circuit. That includes on the ground side. The majority of electrical issues I have checked out on other folks cars have been due to bad grounds. I can't see why anyone would have electric fans and fuel pump hooked so they come on when the cut off switch comes on and not be operated by separate switches and relays that are controlled by the ignition switch. The cut off switch if fine both for a car that sits a lot to cut down on parasitic drains and as theft protection but that doesn't sound to be wired right. Possibly both have rocker or toggle switch that have been left on though.
I'm struggling to think of any positive (no pun intended) qualities to having a car wired that way, only negatives (again no pun intended!). Dark night, problem with car (flat, out of gas, deer through the headlights.....) and to be able to have the lights on, headlights or hazard flashers, you need to have the fuel pump and fans whizzing. Madness! Or to be able to plug your dead phone in to be able to call for assistance. Or listen to the radio whist the good lady is in the store. The list goes on! Sorry for the negativity! Chris
My suggestions, Pull battery out and have it checked at Oreillys or anywhere that can pull it down to simulate start, make sure all battery connections are clean/good. I would change wiring so you can turn on fans after start as fans draw big juice, my spal unit does, suggest you purchase spal thermostat control for fan, then fan comes on when needed. I went through a problem similar and a Walmart battery that was bad within 1 year, gave me another, warranty n/c and the second one was bad, changed battery brand, car ok since. I had a thread on what I went through, to read, go to my profile page, featured threads, read. Good Luck, I hate wiring/electrical problems, not really my area of expertise, but I did learn, start at the source.
Fuel pump should never be wired for full time on, you really need to get a safety switch in place. Most use a oil pressure switch so pump only runs when oil pressure is present. You have a real fire hazard going as it is now! Have battery checked, clean every ground you can find, add larger ground cable from battery to engine if possible, or at least from frame to battery and frame to engine. THE BIGGER THE CABLE DIAMETER, THE BETTER IT WILL START !
have a parts store (your choice)load test the battery a multimeter will tell you nothing except the voltage maybe. as someone said you need amps.
Thank you guys for all the input. The battery voltage when measured with multimeter read 12.5V but as you suggested, I do not know the amps. I will take the battery to parts store to check it. I will also check the battery cables, I know the + cable had some deposits at the connection, which I cleaned but maybe the cable itself is bad (I did not think of this) so I may change it as well. I agree with you that the wiring sequence is quite weird, but he did a really clean job at wiring it, and as mentioned it worked just fine for 5K miles until yesterday. I really hope that either battery, cables or the switch is the culprit as I do not want to chase electrical gremlins.... If you can think of anything else, please share. I will should time tomorrow to mess with it...will report back. thank you.
As mentioned then have the battery load tested then start checking connections Sent from my iPhone using H.A.M.B.
Definitely have an Improved fuel pump circuit. So it runs only when essential. I've seen Ford liquid-mercury cut-out switches, so if a sudden jolt is felt, relay drops out & pump shuts down.
Well.....it was the battery after all. Took it to the auto part store and did a load test, which the battery failed miserably. So bought new one, installed and went for a drive. Thank you all for your inputs, I appreciate it as I would be probably still scratching my head right now! Have a great day guys!
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