wiring again

[joe hermanek]

This plus is behind the dash cluster, i've been trying to figure this out, i'm at a lose ,in the picture there is a joint or plug of some sorts it has 2 wires on each side , the side closet to the radio is a solid blue wire with a green/orange stripe on the other side closest to the ignition switch the wire are red/brown stripe the other is red/orange stripe the red/orange stripe is just hanging there not wired to anything but is's hot when you turn the key to start ,but not hot on the accs. side, also the light for the heater control won't come on I checked bulb it's ok, also still can't get gas gauge to work ,I checked the arm in tank it ohms out ok I shorted the orange wire to frame gauge didn;t move it has aux tanks could it be in the switch that switchs the gauge back & forth? there is no relay by the gas tanks under the truck all that was removed by previous owner, the gas lines are capped off could that be my problem with the gas gauge maybe it's not completing a circuit thanks as always !

[Thunderfoot]

What year is your Truck?

On the gas gauge if your truck had the factory Aux tank (not the ones with a hinged door on the side of the bed or filler in the wheel well) then there would have been a switch on the dash to select which tank the gauge was reading from, and then there would have been a manual switch on the floor by the side of the seat to switch the gas flow... so need a bit more info there for switch or not... Also, what kind of instrument cluster do you have, does it have all gauges or does it have dummy lights?

[fordman]

do you have other dash lights that work? if not check the fuses and the fuse holder prong top make sure they are clean and that power is goign through the fuses.

[joe hermanek]

the truck is a 1970 f-250 ,auto ,390 3/4 ton. The dash has gauges, there is a switch on the dash for switching over for thr fuel gauge it does have the factory aux set-up there is no filler door or wheel well gas filler thanks

[Thunderfoot]

Moderator note: I merged these 2 posts together, please just "Post a Reply" to your original post to keep things in order when working on a single issue to keep it all together... start a new post for a new topic...

Thanks for the added info as it makes a difference in the wiring/wire routing of the truck depending on options it originally had.

The wires you have in the pick of are as listed;
Red/yellow striped wire is for the "Brake Warning" light on the dash this wire is connected to the light and then has a Violet wire from it to the Brake Warning Switch in the brake line in the engine compartment.
Blue wire is for a "Throttle Solenoid" that is on some trucks with emissions control on them.
Green Red striped wire is the "Exciter" wire for the Voltage regulator, this is the wire that tells your alternator to start charging.
Red/Green striped wire is connected with the Pink wire at the ignition switch, this is where the power comes from for all these wires when the ignition switch is in the Run and Start positions.

The wire colors will have probably changed color tone with the age but you should be able to figure it out from here... My guess is that the Red/yellow striped wire is the one that is unplugged and is the one that goes to the "Brake Warning" light on the left side of the dash. NOTE: this is not a warning light for the E-Brake this is for an imbalance in the brake lines and is caused by a leak in the brake lines somewhere...

For the Gas Gauge; yes I would look at the switch on the dash for a problem with making connection, others have had issues with the switch going bad and not making connection.

For the Heater Control light look for/check the Blue/red striped wire, this same wire is connected to the instrument lights and also the Cigarette lighter light if it has one.

[joe hermanek]

well I got the lights to work,bad light switch.But I still can't figure out that red/orange wire on the back of the brake warning lite I do see the violet wire going into the lite but I don't see where the red/orange wire would go is there a place for it that i'm not seeing, also could I change the dash bulbs to brighter bulbs or would they get to hot ,the book calls for 2-c could I go to a 4 or 6 c ? The last question I have is regarding the fuel gauge which won't work it has 2 tanks I looked under the truck & where the switching mechanism is I see 3 ports with no hoses going to them they are cut off & plugged I thought I would see a relay or fuel pump of somesort, but what I have is a mess of wires cut and tapes up is there a diagram for how this all works? thanks again slowly but surely

[Thunderfoot]

On the Brake light plug I will have to get a pic of mine (unless someone else has a pic of the light socket) for the 2 wires, But here is a diagram for it http://www.fordification.com/tech/wirin ... glight.jpg the Violet wire is connected to the side of the housing and is the "Ground" connection for the bulb, the Red/yellow striped wire is the power to the bulb and is connected to the center of the bulb. (note: the bulb is not grounded through the dash it is through the Violet wire)

For brighter Dash lights I would look into LED replacement ones.

For the Fuel Gauge Selector Switch it is not mounted in any way with the Gas line/tank switch on the floor....

The Selector Switch is mounted on the bottom of the dash by the ignition switch (see attachment) and here is the wire diagram http://www.fordification.com/tech/wirin ... x-fuel.jpg (just don't get thrown off with the "fuel pump" labeling as these never had electric fuel pumps in them, it is just the gauge)

[joe hermanek]

I think I'm on the home stretch now, 2 things on the brake lite by the parking brake the red lense is broke how do I fix that or where would I get a replacement . What would I check for now on the fuel guage, I did the orange wire test by grounding it out , nothing changed, how would I check to see if tank selector swicth is bad , or how would I check the gauge itself, I ohmed the gas tank float thats o.k thanks again getting closer

[Thunderfoot]

For the brake warning light check the "Links" tab at the top of the forums and look some of the suppliers there,,, Dennis Carpenter has them part # D5TZ-10A840-A

On checking the tank switch you need to try grounding the wire going to the gauge from the switch to see if the gauge works, if the gauge still doesn't work and your Temp and Oil do then the gauge is probably bad...