Wiring harnesses problems

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res1vw21

res1vw21

It's only metal
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Well I am having a little problem with wiring. I am putting in a '68 rally dash to a '71 swinger and am using the key in the dash. I have spent a lot of hours tracing the wiring diagrams and concluded that the '68 dash harness will work with the '71 engine harness because all but a few of the wires go to the same place. I changed the location of the wires that are not the same so everything is now in the same location.

When I turn the key to the on position I get power to the wiper, heater blower, lights, including interior, map and dash, and radio. I don't get turn or flashers but I also don't have the steering column hooked up so I don't expect to get them.

I do not however get any power to crank. The power cuts out on the radio but the engine will not turn over. The Amm meter has been bypassed, by soldering the two wires together and checking resistance with a multi meter.

I also don't get a reading on the fuel gauge but I don't know if the tank is almost empty or not, I know how to check the gauge though but grounding out the sender. (I just haven't done it yet) I also don't see any provision for the 3 prong voltage limiter on the rally dash.

Here is the strange part if I plug the '71 harness (bare harness not in a dash and not grounded to anything) back in and hold the amm meter wires together I can get it to crank and run with the key, sometimes.

I plugged in the '71 harness and nothing happened, I then ran a wire from coil+ to batt+ and jumped the starter relay, the car fired and ran. I then took the wire I ran from coil+ and disconnected it and tried again by the key and it cranked and started. I then plugged the '68 harness back in and got nothing in crank position.

I just bought a new ignition switch for the '68 and have not tried it yet.
Any other ideas as to why this could be happening? The starter relay has been grounded so that there is no neutral safety switch.
 
The only thing I could suggest is to get out the test light and hold the key in the on position while you start looking for power to ignition.Do you still have the fuseable link?
 
pettybludart said:
The only thing I could suggest is to get out the test light and hold the key in the on position while you start looking for power to ignition.Do you still have the fuseable link?
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I think so because it will work when I plug in the '71 harness but I will check that too. Thanks for the suggestion
 
you won't find a provision for a voltage regulator on a Rally dash its built into the fuel guage and can play all kinds of havoc stop and call "Redfish" now before you get it all together , He makes and sells an electronic replacement he calls the IVR get one and get him to walk you through the surgical removal of the old one { it has to come out } , you may as well do it now while the dash is open or you'll probably end up doing it later . He is also the guru on wiring and can probably walk you through your other problems as well
 
Does the 68 harness have the starter relay wire hooked up to the ignition switch? Is it even there?
Sounds like a bad connection from the switch to the relay, maybe in the bulkhead?
I had the same issue with that wire, but it was on the engine harness side.
I'm no electric engineer, but I always use the kiss principle first.
 
yha I will trace that, that seams to one of the leading theorys. I am going to take some pics of another car tomorrow or the next day and I will be near the dart so I will look at wires. Thanks guys
 
res1vw21 said:
anyone else have any ideas?
Click to expand...

Yes, I have an idea......wireless :read2: Did I mention I hate wiring issues....LOL

Keep asking, you'll get the answer. I can't help you, but maybe I'll learn too!!!
 
Have you compaired the wiring diagrahms to make sure they are same configuration. My 67 Dart was different then the 70's diagrahams. When I put in an electronic ignition system. I had to make a couple changes to the wiring. Just a thought.

Dave
 
It seems that you need to ohm/volt 3 wires. Key on- power to coil. Key on crank- power to coil, and to starter relay. Ground the neutral (brown wire) on the relay, bypassing the transmission switch.
 
green1 said:
Ground the neutral (brown wire) on the relay, bypassing the transmission switch.
Click to expand...
Did that still no go

I did however pull the engine harness today and noticed that the plug on the fusable link was not seated all the way. My guess is the dash side '71 harness is pulled out just that far too and made good enough contact to start. I think the '68 harness isn't pulled out and made good enough contact to run things like air but not good enough to crank. Just a theory though. I am going to go through the '71 engine harness and see if at a previous time someone re routed wires.

The ballast resister was also warm to the touch today in run.
 
Hook up the 68 harness and run a new start wire from the ignition to the relay, and turn the key. If it starts your good. Its another way to eliminate a short or wires that are not connected somewhere.
If you have a meter you could also check the wires for continuity.
 
if a 71 ignition switch will start the car and the 68 switch will not... bad switch is my guess.
 
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