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I got my fuel pump to work, now I have ran into another issue. It won't shut off. On top of that my dash lights wont dim and my heater won't work.

 

For those of you who don't know I recently stripped the interior of my Brat to paint and now I'm reinstalling it. I had a grounding problem that was causing a lot of problems but with the help of you guys I figured it out.

 

Now I've ran into more issues, like my fuel pump not shutting off. It worked just fine when I disconnected it. I did a search and it would seem that the most likely problem is that I connected it to the wrong plug, yet here's the plug I connected it to, same color, same wires.

 

It's the black one on the right

post-47847-0-56260500-1373765559_thumb.jpg

 

I'm adding these other issues because they may be related.

 

My dash lights won't dim which is most likely a grounding problem. The only ground looking wire I've been able to find is this guy,

 

post-47847-0-64215700-1373765722_thumb.jpg

 

and it's spliced into a hot wire into the back of the fuse box. Tried grounding it just in case, repeatedly blew fuses. I did convert to LED's

 

post-47847-0-18757500-1373765987_thumb.jpg

 

My heater isn't working. It was working on high, but now not at all. I will admit I had the fan motor apart to check the bushings. They were in good condition. I may have screwed up when I put them back in. Right now, I'm more focused on the fuel pump.

 

I do have this gadget that needs to go somewhere.

 

post-47847-0-98934800-1373766293_thumb.jpg

 

I believe it goes here but the colors on the wires don't match up.

 

The pink one in the center.

post-47847-0-67527500-1373766368_thumb.jpg

 

As far as I know everything else is working. Thanks for the help.

Edited by Godsmulligan
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disclaimer, im not an electrician by any means.  but something to maybe turn up some searches on the site here.

 

I think the pink connecter in the last is for the speakers.  they were on mine, but mine is a different year and generation.  search out common ground and you will find write ups that might pertain to your year so you can check.

 

similar on the square gizmo, there is one that looks like that in my generation of car that runs the blower switch.  in mine it plugs in behind the glove box.  check and see if there is a matching plug there.

 

cant help with the other parts

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Well I guess you have now learned that you can't connect a wire going to power, even though it may be black in color, to a ground point. That is a direct short and fortunately the fuse saved your wiring from being damaged.

 

The fuel pump is usually controlled by a module or the ECU. The power side of the circuit may be switched on your model and the ground for the pump motor run straight to ground. Later models used a controlled ground return. There should be a fuel pump relay somewhere so I suggest you check it to see if something is keeping the relay switched on when it shouldn't be. I don't have a wiring diagram to help you more on that.

 

The dash lights are usually wired to power through the light switch and the return side of the lights is controlled through a module that is tied to the dimmer control though your car may just use a simple variable resistor to control the lights. If the device shown in the second picture is the light switch and dimmer then it appears you just have a resistor for the control.

 

The blower circuit uses a relay on the power side and then it ties to one side of the motor. You should have voltage getting to the motor when the switch is ON if that part is okay. The speed resistors are on the return side of the circuit. So if you manually ground that side of the motor it should turn on full speed when the switch is turned on. If that works and the blower doesn't turn on at any speed then you should replace the resistor pack. The thermal protection fuse may have been blown out in the old one.

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Well I guess you have now learned that you can't connect a wire going to power, even though it may be black in color, to a ground point. That is a direct short and fortunately the fuse saved your wiring from being damaged.

I know, but my last ground issue was a ground wire that had power to it because it was an open circuit. I didn't quite understand that one, but I ground it out, closed my eyes, held my breath and it fixed my problem. Now I don't know what to think about black wires with power.

 

 

The fuel pump is usually controlled by a module or the ECU. The power side of the circuit may be switched on your model and the ground for the pump motor run straight to ground. Later models used a controlled ground return. There should be a fuel pump relay somewhere so I suggest you check it to see if something is keeping the relay switched on when it shouldn't be. I don't have a wiring diagram to help you more on that.

 I checked the plug on the wiring harness, 2 hot wires 1 ground. when I connect the plug all 3 register hot. Trying to track down the relay now. I do have the wiring schematics just having a heck of a time making heads or tails out of them.

 

 

The dash lights are usually wired to power through the light switch and the return side of the lights is controlled through a module that is tied to the dimmer control though your car may just use a simple variable resistor to control the lights. If the device shown in the second picture is the light switch and dimmer then it appears you just have a resistor for the control.

yes it is a light switch and dimmer.

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The blower circuit uses a relay on the power side and then it ties to one side of the motor. You should have voltage getting to the motor when the switch is ON if that part is okay. The speed resistors are on the return side of the circuit. So if you manually ground that side of the motor it should turn on full speed when the switch is turned on. If that works and the blower doesn't turn on at any speed then you should replace the resistor pack. The thermal protection fuse may have been blown out in the old one.

ok thanks, headed out to check this one now.

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Whenever an open circuit has power applied to it you will measure close to the voltage being supplied to it at any point of the circuit you make the measurement at. This is because there is no current flow in the circuit so there is no voltage drop across any loads in series with that circuit. When the ground return is connected then the current flow will cause voltage drops across any loads in the circuit. Most of the time there is a single load in the circuit so all the voltage drops across it. The blower circuit and dash light dimmer circuits have two loads. A series resistor is used to change the blower speed or light intensity. One safe way to see if the wire is tied directly to power is to use a common test light probe. Clip the lead to ground and touch the probe tip to the wire end in question. If the lead is tied directly to power the test light will turn on with full brightness. If there is something else in series with that wire acting as the load the test light will have less than full brightness or not even light up possibly depending on how much resistance the load has. The higher the normal current draw of the circuit is the brighter the light will be.

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FIXED

 

Went to the junkyard today and picked up a *relay for the fuel pump, a headlight switch and I was going to get the heater controls but when I started to take it out I traced the wires back to a plug by the heater core. I recognized that wire as one I didn't have hooked up. I didn't realize the heater fan hooked up in two seperate locations.

 

Went home hooked up the relay, plugged in the new switch and attached the plug to the back of the heater core. It worked, fuel pump shut off, heater works on all levels. The dash lights still don't dim, it could be the switch from the junkyard was bad, but I can live with if for now.

 

Time to put the car back together.

 

Thanks everyone :)

 

* thanks to a thread on here I found that the fuel pump relay is drivers side, behind the fuse box and attached where the hood release attaches. Of course it was the only relay I couldn't get unplugged when I was trying to track it down.

Edited by Godsmulligan
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Glad to hear you got some issues solved. I would suspect the light switch is most likely okay. For the dash light issue I would suspect either the dimmer control is has been bypassed with a direct connection to ground or the LED mod is causing the issue. Due to the diode characteristics of LEDs they don't dim in the same manner as a normal bulb does.

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  • 3 weeks later...

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