Car won’t start no power yellow wire are stater relay

[Gregg1]

Hello all ;working on a 70 challenger just got it registered this week ,in primer 383 4spd car new dash harness ;went through steering column new ignition switch ,ect it was starting fine all of a sudden no power to yellow wire which when you turn key all the way tells the relat to engage starter which is a new mini starter if I turn ignition key on I can jump starter with screw driver on the relay ;it shuts off with the ignition key fine ;the top rh fuse is dead no power but I don't think that has anything to do with this problem,any ideas I tried a different ignition switch just plugged it in under column no difference ;any ideas here it's a common problem thanks in advance

[Katfish]

Does it have a neutral/clutch safety switch?

[Gregg1]

Does it have a neutral/clutch safety switch?

.  No I have the starter relay grounded,it was fine this is a new problem

[Bullitt-]

  Wiring connectors may be the issue. I've read several times that a poorly seated connector had pushed out. Pay attention to the wide flat connector along the steering column. Test for voltage in & out on the yellow wire there and at the bulkhead connector with ignition switch turned to start.

[Gregg1]

Thanks ya no power at starter relay yellow wire I'll ck those connections thanks

[dodj]

The bulkhead connector should be checked as well.

[JS23U]

I've been through a no-start problem as well over the last weeks on my 70 Challenger. As previously said, check the bulkhead connector. Pull off the plastic connectors from the engine bay side and check every contact with a flat connector if it snugs right in and sits well, not loose. I found one (coincidentally also the yellow one) where the connector on the inside of the car was bowed open so much that the joint didn't have electrical contact anymore. Also check that the interior-side parts sit tight in the plastic housing and can't be pushed through when connecting the plug from the engine bay side. Again, check each connector. It doesn't hurt to clean the connectors, also.

Another place to search is the white flat connector under the steering column where the 6 or 8 wires come from the ignition switch and are connected to the dash harness. Those connectors are cylindrically shaped and if the outer one has too big of a diameter the fit is loose or it even has erratic or no electrical contact. I had to carefully squeeze the ones on my car to get a tight fit. This is especially true for aftermarket iginition switches which seem to be very loose at that joint. The connector for the turn signal switch is similar.
It took me quite a while to find out all that stuff...