FYI FORD - MustangSteve's Ford Mustang Forum
The Internet's Most Knowledgeable Classic Mustang Information
IF YOU HAVE A QUESTION ABOUT CLASSIC FORD MUSTANGS, YOU HAVE COME TO THE RIGHT PLACE!
MustangSteve has over 30 years of Mustang experience, having owned 30 of them and restored several others. With the help of other Mustangers, this site is dedicated to helping anyone wanting to restore or modify their Mustang.... THERE ARE NO DUMB QUESTIONS!!!!!
Visit MustangSteve's web site to view some of my work and find details for:
FYIFORD Contributors' PICTURES - Power Brake Retrofit Kits for 65-66 Stangs - Classic Mustang FAQ's by MustangSteve - How to wire in a Duraspark Ignition - Mustang Ride Height Pictures and Descriptions - Steel Bushings to fit Granada Spindles to Mustang Tie Rods - Visit my EBAY store MustangSteve Performance - How to Install Granada Disc Brakes MustangSteve's Disc Brake Swap Page - FYIFORD Acronyms for guide to all the acronyms used on this page - FYIFORD Important information and upcoming events

You are not logged in. Would you like to login or register?

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  » Need help with wiring problems

    • 1 of 1

       

    10/17/2013 6:37 PM  #1

    whlnut
    I FYI 24-7

    Offline

    From: Brunswick, GA
    Registered: 4/02/2013
    Posts: 317

    Need help with wiring problems

    I'm still trying to put my '66 fb on the road. Issue 1) the original CVR smoked the first time I put power to it, so I replaced it with a solid state one. Now the fuel gage reads right but the oil pressure and temp peg to high with the key on. I replaced the ammeter with a volt meter. Key-off, the needle is at D; key-on, engine running or not, it pegs past D. Positive power from ign side of CVR to one side of vm, dash ground to the other. Dash lights work. All dash wiring looks good. No blown fuses.
    2) I added a harness/relay kit for H4 headlights. I can't get the high beams to come on. They work with the original wiring. Parking/running lights work. The turn signals were working, but not now. I suspect a poor ground somewhere. Headlight low beams were dim on pass side untio I ran ground from neg post of batt to core support. Neg batt cable to block, block ground to firewall and block to valve cover bolt.  Brake/tail lights work.  All bulbs are new or tested good.
    Also, while the engine is running in park, and brakes are applied, rpms drop slightly and resume with brakes off. I'm not sure if the stock rebuilt alternator is charging or not. I just ordered a harness and feed cable to swap the 3G alt that i have. Will check for charge this w/e.   Any ideas??

     

    10/17/2013 7:09 PM  #2

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,818

    Re: Need help with wiring problems

    I'm getting ready to go to bed but will get you started. First it sounds like the oil and temp gauge are connected directly to ground, not to the sending units. This is why you burnt up your first CVR and why both meters are pegged now. This needs addressed first or you will burn up your electronic CRV or worse your meters. Second if I am reading your post right you have the CRV out put connected to the volt meter. The volt meter should be connected to switched 12 volts. What do you mean by D on the volt meter?

    If this forum can't fix it, it isn't broke.
     

    10/17/2013 7:43 PM  #3

    whlnut
    I FYI 24-7

    Offline

    From: Brunswick, GA
    Registered: 4/02/2013
    Posts: 317

    Re: Need help with wiring problems

    The gauges are connected to the senders. I jumped a wire from positive switched power at the CVR input (IGN) connection, to the vm. CVR output to the 3 gauges only. Thanks

       •Thread Starter
     

    10/17/2013 7:54 PM  #4

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,818

    Re: Need help with wiring problems

    Ok sorry, so on one side of each gauge you are reading + 5 volts. If you have that, lift the other wire off the temp and oil gauge. Measure resistance to ground. Should be more than 10 ohms closer to 50 ohms. Do you have a meter to do this?

    If this forum can't fix it, it isn't broke.
     

    10/17/2013 8:33 PM  #5

    whlnut
    I FYI 24-7

    Offline

    From: Brunswick, GA
    Registered: 4/02/2013
    Posts: 317

    Re: Need help with wiring problems

    I have a meter but I'm at work. I will check tomorrow. Thanks

       •Thread Starter
     

    10/18/2013 9:06 AM  #6

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,818

    Re: Need help with wiring problems

    Another thought; are you sure the sending units you have are for gauges and not for lights?

    If this forum can't fix it, it isn't broke.
     

    10/18/2013 2:00 PM  #7

    whlnut
    I FYI 24-7

    Offline

    From: Brunswick, GA
    Registered: 4/02/2013
    Posts: 317

    Re: Need help with wiring problems

    Yes, original type senders and wires. Gauges used to work before I took the car apart. Only change to gauges is new volt meter in place of ammeter. I am not using the wires that went to the ammeter.

       •Thread Starter
     

    10/18/2013 6:26 PM  #8

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,818

    Re: Need help with wiring problems

    OK lets start over. Your electronic CVR connects to each gauge (Oil, water, fuel). Where it connects to the gauge you should read 5 volts to ground. The other terminal of the gauges should be some what less than 5 volts to ground. If it is zero volts you have a ground problem. If the other terminal is greater than 5 volts to ground there is another wiring problem. Make some measurements and let us know. You could lift the wires from the sending units (oil and temp) with key on gauges should read near zero. Once again what is 'D' on the volt meter. Could the wires be backwards on the volt meter?

    If this forum can't fix it, it isn't broke.
     

    10/18/2013 10:21 PM  #9

    whlnut
    I FYI 24-7

    Offline

    From: Brunswick, GA
    Registered: 4/02/2013
    Posts: 317

    Re: Need help with wiring problems

    Gauge problem was the CVR. Output was 8.3v. I adjusted it down to 4.7, which puts the needles just below mid-sweep. I think you were right abt the volt meter. I swapped the wires and it now moves to about 3/4 sweep towards the Charge side w key on, and a hair further w engine running. Stays at D, or discharge with key off. Thanks!
    Now to the high beams and signals.

       •Thread Starter
     

    10/19/2013 8:19 AM  #10

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,818

    Re: Need help with wiring problems

    I'm going to do a little guess work but any information you can give us on what type of kit, wiring harness change or posting a diagram would help. You should have 2 wires from the high/low beam switch, they go through the firewall connector to the front of the car. One is red/black and one is green/balck. I'm going to assume you have 2 (or maybe 4 relays) relays for the lights. One for high beam and one for low beam. The red/black should go to the coil of one relay the green/black should go to the coil of the other. Turn on the lights one of the wires should have 12 volts to ground and one (or 1 pair) of the relays should pick up. Click the high/low beam switch. The other wire should have 12 volts to ground and the othe relay (or other pair) should pick up.

    If this forum can't fix it, it isn't broke.
     

    10/19/2013 9:17 PM  #11

    whlnut
    I FYI 24-7

    Offline

    From: Brunswick, GA
    Registered: 4/02/2013
    Posts: 317

    Re: Need help with wiring problems

    One of the brand new relays looks like it had acid poured inside it and burnt it up. Outside at the prongs is all green corrosion. Other relay,has a little corrosion. I should have pulled the connectors off,before installing. It was a $30 ebay kit from China, I presume. I will get Bosch relays tomorrow and start over.  I did get the blinkers working. The 4-way flasher knob in the steering column was pushed in, but not yet wired to work.

       •Thread Starter
     

    10/20/2013 6:14 AM  #12

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,818

    Re: Need help with wiring problems

    Cool! sounds like you got it all figured out.

    If this forum can't fix it, it isn't broke.
     

     

    1 of 1

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  »  Need help with wiring problems

    • Board footera


    REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.