I've rewired a couple of other cars without problems, but this is making me crazy! I'm rewiring a '59 pickup. New wiring harness (Rebel Wire), switches, gauges, lights- the whole shot. It starts and runs fine, and with the key in the run position the hazard lights go on, but they don't flash. With the ignition switch in the off position, everything is off as it should be until you turn on the hazard light switch. Then the Hazard lights flash as they should, but in addition to that the fuel pump pulses, and I can see the needles on the electronic gauges move slightly with each pulse. Fuel pump is wired through a relay. The relay is switched on by the "Ign" on the ignition switch, and gets its power through a fuse direct from the battery +. I also tried byp***ing the switch and switching it direct from the battery power with the same result. Hazard switch is an old (But new in the box) Roberk add-on switch like this: It gets its power from the "Hazard" wire in the harness, and connects to the parking lights by tapping into their individual wires. I pulled the flasher out of the Rebel Wire fuse panel so I don't have a flasher running another flasher; I ran extra temporary ground wires from the lights to battery- with no change. I just can't see how my fuel pump (or fuel pump relay) is getting power from the flasher??!! What am I missing?
Sounds to me like you have ground issues, the electricity is looking for a place to go, through the gauges, anywhere it can. Run a ten gauge wire as follows, one to the block to the body, block to frame, body to frame, block to battery, ground the gas tank too. The biggest thing is to keep the smoke in the wires, be careful.
The harness could have wiring issues before you touched it. But first maybe try putting the Rebel flasher back in the panel and removing the flasher on the switch but jump it with a short wire........ or test it with another switch and the Rebel flasher.
Just move the electric fuel pump to a different "ON" only circuit. I remember MOPAR'S used to have a similar issue; key off, turn on the 4-ways, turn on the radio, flip the turn signal lever to Rt or Lt, and get a pulsed radio (???). My OT 70 340 Dart did that brand new, as did a friends 69 340 Dart. I am Butch/56sedandelivery.
I'll bet you have the 'power' and 'load' terminals on the flasher switched; it does make a difference. This explains the lights on but not flashing with the key 'on'. With the key off but the flasher on, it backfeeds into the fuse box and pulses your pump relay and gauges.
I hate wiring! I rewired my instrument cluster and now the only way my tach works is I have to turn on the aux fan?
Pop's Ford truck would do the same thing. If I put my foot on the brake, the radio would play just like normal, and the flashers would stop flashing, but the brake and park lights would be on. I could only do this for a few minutes w/o running the battery down, but at least we had a few minutes of music between Sunday School and Preaching.
Well... 1. I swapped the power/load leads on the flasher- Pump still pulses. 2. Double-checked & cleaned grounds (Bat- to head bolt, Frame to block, Fuel pump to frame, park lights to body)- no change 3. Ran temporary ground wires direct from Batt- to: -Hazard switch (it grounds through its bracket) -Fuel pump -Parking lights (they ground through each individual bulb socket to the body ordinarily) Had wires and alligator clips everywhere, but still no change. 4. With fuel pump ground disconnected the hazards work normally fwiw, but obviously the pump doesn't work at all. 5. Tried two different flashers: one electronic, one conventional. No change with either. 6. Tried skipping the fuse panel altogether (I mistakenly said I'd skipped the switch toward the end of my original post) and ran power directly from the battery to the switch- No change. I know this is going to turn out to be something stupid, but I'm just stuck! Any other suggestions would be appreciated.
Put a voltmeter on the fuel pump wire, see what it does when it is "pulsing". My guess is that the supply voltage to the pump is dropping a little bit when the flashers are going, and you just hear it in the pump. I've had the same thing happen on my old cars, it's been going on for decades and I don't worry about it. (btw wife's 70 Dart has similar issues with the blinkers even though it doesn't have an electric fuel pump, has been acting weird for decades, I don't worry about it, either. It keeps running)
Squirrel- The fuel pump shouldn't be getting any voltage at all when this is going on- key is in the "Off" position. It should only get power in Start and Run. It is pulsing when it shouldn't be running at all, right?? Hazards must be triggering the FP relay somehow ?...
Well, that's a clue.... Check the pump wiring, particularly the wiring for the pump relay. Make sure the pump (and relay) and the hazards are on separate circuits.
Ok- I found the source of the problem, and even though I don't really understand how this caused the problem I'm posting it here in hopes that it will help someone in the future. Warning: I did say in my original post that it would be something stupid... I'd re-positioned my brake pedal right before this problem started, and didn't notice that in the process it no longer pressed on the brake light switch, so brake light switch was always in the "On" position. As soon as I got the brake light switch in the "Off" position the fuel pump stopped turning on with the emergency flashers. Problem solved, but I still want to know why this caused this particular problem. If someone could please explain it I'd sure like to know!
If you pushed the brake pedal instead of flipping the turn signal the radio would play normally. Only killed the battery twice in my Grandfathers '69 Fury III listening to the radio that way. I was 14 and car crazy. Was very firmly encouraged not to mess around in Gramp's car anymore.
That would mean that the flashers were feeding back though the brake light power circuit. That may mean that you have the brake lights wired into the "switched" side of the fuse block rather than the non switched side. Quick test, do the brake lights come on when you push the pedal with the key off as they should or do they only come on when the key is in the ON position? I'm thinking you have them wired into the keyed side of the fuse block or have the feeds switched for the fuse block.
Bad ignition switch......Switch is getting power across in Off Position.......Put a Ground wire on the Hazard Switch, might not be getting good ground off Dash Panel. Just some Ideas as I set and Ponder. How many amps is the ignition Switch rated for and how much load do yo have on it?
A final update: Mr48Chev had it right: The "Always Hot" wire from fuse panel to brake light switch was only hot with the key on. I don't know if Rebel Wire does it this way on purpose for some reason, but there it is. I ran a new always hot wire (that really is always hot) and everything works now. Thanks to all who offered suggestions.
Is the flasher one with a coil in it?..Steve might be able to best explain, but when building a DC charge in a coil, once the field has collapsed, the stored voltage has to go some where, I know on cheap little DC relays, you put a diode in them (again, Steve will know where) to stop the voltage from going back into the circuit...could be what you are seeing? Oh heck, Squirrel would know as well what I'm talking about and if it has any bearing on the issue.
This was a straight backfeed issue, combined with the maladjusted brake light switch (proving once again that where electrical problems are involved, no detail is too small). The 'coil' type flashers also use a capacitor (which is how they flash), and it will absorb any voltage spikes generated.
The harness kits force you to do it THEIR way. Once you wrap your head around the concept, things go better.
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