I'm going through dash lights and trying to figure out why some stuff doesn't work. Tried search but am not finding direct resolutions.

I have a 1970 with a 2.0 block, dual webers. I am assuming that the "upgrade" is common one and was done at the same time. hopefully a cam in there somewhere.

At some time the center console was added. With all this 'work", the engine compartment now has tapped and chopped wires, and other loose wires of different color (these don't get power with ignition), etc. Most all electric works except for the following:

So I am thinking i have just have to rewire certain things directly.

1- (not working) Tach is getting power and all connections seem stock...of the few loose wires, engine compartment has no visible "brown" wire and nothing is connected to the neg side of the coil other than one wire going to the distributor.

2- I have a temp gauge (gets power doesn't work) in the center console that isn't labeled and goes to 300 so i guess it's oil temp. it gives off one green/blk striped wire that is cut and attached to a purple wire (DAPO?) that disappears down next to the shifter...in the engine compartment there is a purple wire (hopefully the same wire?) attached to the sensor just back and left of the distributor. I changed this sensor (when the old one leaked) with one that was included with the car. Sensor only has one terminal. I don't think it worked before that either)

Idiot pressure light lightens when I start the car but goes out.

I question...is this sensor for the idiot light? Is this the right gauge for the console? I don't think I have the Taco plate sensor (assuming it's easy to see in the center of the oil sump. Are the oil pressure and oil temp senders similar sizing? All mixed up.

3- With the car off, clicking the turn signal lever sets off the headlight motors (not the lights) going up and down repeatedly. Kinda funny actually. they start out even and then go out of sync...like it's getting dizzy. I know this is wrong.

Should anything happen? I thought I read somewhere that the left and right side of the car is supposed to light...like modern cars. >_>

What in the bindle of wires that come up through the various hole in the engine tin?

Appreciate all suggestions, remarks, etc...

Wow, you certainly do have a lot of issues going on.

Best thing to do is to attack them one at a time.

For the Tach, you are right, a 2nd wire should be on the NEG side of the coil and make its way to the tach through the relay board. If it's missing, then the tach doesn't work.

For the temp gauge, it connects to an oil temp sender on the bottom of the engine. Look under the car at the engine. On the driver side on the oil pan, there is about a 4 inch round plate with either no wire and is flat or has a bulge (that's what she said) with an opening with either no wire or a wire going to the top of the engine. If it isn't connected the oil temp gauge will not work.

Let's stop there and fix these issues before heading to the headlight/turnsignal function.

Tach-Is there an engine side wire for the tach that comes from the board or should i just route a new, direct wire from the tach?

Temp Sender so Can i assume the sensor on the top of the engine is for the pressure light? Where should that wire come from...board again? if i don't have a wire on the oil pan then i suppose the guage was just added for looks...

I don't know what condition the existing wiring is in to/from your relay board but if it were me, I'd try to run engine wires to/from the relay board. Some or most of the wiring may still be connected. You just have to find them.

There are schematics and information for your car on Pelican Parts. I'm not sure where on their site but search and you will find them. Use them as a template for re-wiring.

Do you have a volt-ohm-meter? If not buy one; you'll need it over and over again in your 35+ year old car with hacked wiring.

If your car is a '71 then there's no provision for a temp gauge in the stock wiring harness. The later cars have the sender plate (or taco plate) on the bottom of the engine with a wire coming out and it connects to a single connector on the right side engine shelf just below and forward of the battery tray.

Quickest and easiest way to sort things out would be to install a complete 73 wiring harness. The second option would be to retain the front half of your harness and find the back section of a 73 harness. Later harness will work but they will need rear light modification. 74 and some 75 have the dreaded seatbelt interlock.

I agree with Spoke.

If you pull the harness, you are going to be down for weeks.
If you take it one wire at a time, you can be done in a weekend.

Get a wire diagram for your car. There is one in the Hayens manual, and you can find color diagrams here and from AA.

When I was tackling wires, I actually made the color wire diagram the background of my computer screen at home and at work. I looked at it for hours a day while doing other things, and got familiar with how things were supposed to work. It has made my electrical life easier.

Go one wire at a time and you can tear through it. if you look at it as a whole you are going to get overwhelmed.
Zach

To my surprise, my 71 914 was wired for the temperature gauge from the relay board into the interior to the center console.

Note below on the 71 for USA schematic item 42 (optional oil temperature sender) and missing item 86 at the top right hand side which would be the oil temp gauge.

The wire enters the relay board on the 12 pin connector on pin 3 and exits the board on the 14 pin connector on pin 6.

Wiring the oil temp for the 71 what is needed is the taco plate with the sender, wiring from the sender to the relay board. The wire from the relay board to the center console should be there already.

I looked quick last night and started to tear off the covering on the wire bundle at the back of the board. Not sure if DAPO used shrink tubing that has hardened or what but the covering is like really hard plastic...even metal like.

I'm not sure at this point if the board was ever changed. i spent the night looking at the Haynes diagram with a flashlight and a magnifying glass. After uncovering the wires I am seeing nice clean colors. Taking a closer look tonight.

Decided I'll work on this wire bundle...should get teh tach and oil pressure light working. Still need to check for a oil temp sender. Do I need to jack her up?

For oil temp do I require a taco plate? is that the only way a sensor was added? Can someone post a picture of it on the engine? I've seen images of close-ups but not in a general view of the engine.

Also did these cars ever have cylinder temp? Where does that gauge
go? Any general pic of the sensor location?

My console has a clock, oil temp and volt gauges.

early cars may not have the factory harness for al the aditional gages. I have added my own wires for gages on early cars. I will ad a couple extra wires in my own bundle for future use (like adding a head temp gage later)

run the new bundle thru the tunnel via a new hole you make in the fire wall, usea gromment on the hole and sleave the entire bundle. make sure you do not poke into one of the fuel or hydrolic lines in the tunnel when you drill


the oil pressure idiot light can be made to work with a two terminal oil pressure sendor (has one terminal for a gage, one for the idiot light) some sendors only have one terminal, that is for a gage, and you have no light function.
if you use the single terminal pressure sendor, then you can use the old idiot light wire that runs to the cockpit, just remove it from the idiot light and lengthen it to reach the pressure gage.

I prefer running my own wires verses using the relay board terminals for the oil temp , that is becuase when using the relay board, your adding potential resistances with the extra connectors, however it will usually work fine that way.

use fine stranded wire for all your wires in teh car, dont use signle strand or course strand. the fine strad resistes fatigue breakage better than course or single strand.

I recommend teflon wire around the engine if possible, as it take the heat very well. speaiclly the underside wires like the oil temp sendor

for the oil temp sendor youwill need the two plates (base mounting plate and the cover plate) the big o-ring the paper gasket (goes between the two plates) and teh screws with sealing washers. non oil temp equiped cars had a rather flat plate there only.


good luck

Well I got the tach to work...yay. Also I hooked up the oil pressure light and that lights up now when i start the engine...another yay.

I also checked and don't have a taco plate. The pressure gauge was connected to the light sensor. So now i have an oil temp gauge and no sensor.

Am I better off just getting a taco plate and sensor or should i swap the gauge for a head temp gauge and sensor? Which is more useful.

Other strange happenings:
- headlights go up and down when turn lever is clicked and ignition off

- With ignition on, the fuel gauge fluctuates about 1/4 of a tank when I turn the headlight rheostat. Goes from empty to full when ignition off