1970 RR No power at ignition

[dcoland70RR]

I'm confused by your description as "decaying". Could they be oxidized or is the plastic bulkhead connector burnt from overheating? Oxidation is an easy fix. Overheating is the result of another problem.

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Oddly enough, mine (not pictured) was in great condition for a 48 year old survivor. I consider myself extremely lucky.

Thanks for your photo. Mine do not look terrible but the port on the firewall that the large blue fuseable link wire that comes from the starter relay into the firewall dash plug looks rough. The port for it on the firewall from the dash side is so decayed like that the metal port is almost gone, like it just decayed to dust over time. What bothers me more is that some previous owner (unknown who) in the past drilled a large hole through the middle firewall plug and put an aftermarket wire and plug straight through the factory plug to connect with the center engine wire harness. I followed this wire under the dash and it is just tied into a wire from the dash harness that was clearly cut open and tied into a wire under the steering wheel shaft, not in a factory related way. Overall its not terrible but my awesome RR is not starting due to no power at all to the ignition more and more often. This started only once and a while and is now happening 75 percent of the time I try to start it. every time this happens I have to unplug the engine wire harness, kind of blow on it or spray cleaner on it, then wiggle back into the firewall as best as possible and the car starts great. Then 20 minutes later wont start again so clearly time to replace it all due to decay and someone hacking it up a little. So due to this I do not want to hack up the factory plugs further, I am ordering all new wire harness from YearOne with a 30 percent off code they just sent me after I placed a small order a few days ago. This means I can get all new harnesses including: front light harness, engine harness, rear light harness, and complete dash interior harness that are all totaling about 900, after the 30 percent off code they sent me all comes out to 650 which is awesome price for entire new wiring bumper to bumper

 

[Sixpactogo]

I mentioned in post 14 the possibility of the starter relay being the cause of the intermittent loss of ignition. I had a brand new relay act that way. I know you have other concerns to deal with and all are potential issues. If you have power to your fuse box, light switch and other electronics, but not to the start mode, that means that your fusible link is intact and your problem is elsewhere. On a 4 speed car, you do not have a neutral safety switch on the transmission but you probably do on the clutch. I still think your problem is in the starter relay itself.

 

[dcoland70RR]

I'm confused by your description as "decaying". Could they be oxidized or is the plastic bulkhead connector burnt from overheating? Oxidation is an easy fix. Overheating is the result of another problem.

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Oddly enough, mine (not pictured) was in great condition for a 48 year old survivor. I consider myself extremely lucky.

So just took photos of mine, when I started having electrical no power issues I noticed the green in color neutral safety switch wire that runs from the clutch pedal area to the starter relay, the green wire part that plugs into the starter relay was falling apart and the wire was hanging on by a hair sized thread. Then noticed the yellow wire from the motor wire harness plug that goes to the starter relay was also falling apart and hanging on by a tiny thread right at the plug. Then days later when I opened it up found someone drilled through the firewall plug to hack into it, so I think best at this point to replace it all myself slowly and efficiently over the winter.

 

[dcoland70RR]

pics

 

[Bruzilla]

As wire gets older, it gets brittle and starts to break, especially when you start bending and twisting it. The outside cover looks fine, but there are tiny gaps in the copper that the electricity has to essentially jump across, and if that gap becomes too big, that wire is dead even though it looks fine visually.

You could have one of these wires in your system right now, and just hitting a bump, or a shift in momentum from coming to a stop, can cause that gap to widen to where you lose continuity until the wire returns to a position where it is restored. The good news is it sounds like you know where your problem is, so I would just trace those wires back to the firewall, cut each one off and splice in fresh wire. That's a lot cheaper and easier way to fix the issue than buying a new harness.

 

[dcoland70RR]

Not a bad idea at all. That's what I am going to work on today and tmrw when free just so I can enjoy it til season end. Then when car is stored for winter could always replace harnesses if needed when car is down for months.

 

[NJRR]

As wire gets older, it gets brittle and starts to break, especially when you start bending and twisting it. The outside cover looks fine, but there are tiny gaps in the copper that the electricity has to essentially jump across, and if that gap becomes too big, that wire is dead even though it looks fine visually.

You could have one of these wires in your system right now, and just hitting a bump, or a shift in momentum from coming to a stop, can cause that gap to widen to where you lose continuity until the wire returns to a position where it is restored. The good news is it sounds like you know where your problem is, so I would just trace those wires back to the firewall, cut each one off and splice in fresh wire. That's a lot cheaper and easier way to fix the issue than buying a new harness.

Bru- what you described was exactly what my problem was with my negative battery cable. From the outside, it looked fine. When opened up, it was oxidized, very brittle and virtually crumbled in my hand. I had intermittent starting problems, battery wouldn't charge. Changed the cable and no more problems.