1970 Hemi RR 4 spd keeps running after turning off key
- Thread starter Lucky Lar
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Are 66 and 70 Hemi alternator, right side harnesses the same? I have an extra one of those for my 66, unused from M&H if the same and your interested. It seems like the 66 has a black plug. I had already bought one and then realized my light harness was bad too and ordered it. It included another Hemi alternator harness that I was unaware of.
Only issue is I had some back surgery today and it may be a week - 10 days or so before my wife will let me slip out to the garage to get it.
If all the wires are otherwise good, you might just be able to get some Packard terminals and a new 6 wire plug set and repair it. But I would check the plug and bulkhead connections for that harness also.
Only issue is I had some back surgery today and it may be a week - 10 days or so before my wife will let me slip out to the garage to get it.
If all the wires are otherwise good, you might just be able to get some Packard terminals and a new 6 wire plug set and repair it. But I would check the plug and bulkhead connections for that harness also.
Lucky Lar
Well-Known Member
Thanks for the offer, but i ordered a new one yestrday form Year One
I hope they have it in stock. I ordered 6 items from them in mid-December. I received one item in about 10 days (a can of spray paint) - no notice, tracking, nothing. The other 5 items back ordered. Three more items trickled in one at a time over the next month and half - again no notice or tracking info. Two items are still on back order over two months later.
But, good luck with the repair.
But, good luck with the repair.
What would have caused the wires to melt together? Overload or poor connection? Not the same issue; but I had a stall out problem that took me a while to trace down. It was a loose ignition wire at the BH that would vibrate loose. This finally prompted me to tackle installing a new BH as it was in rough shape anyway. The engine harness was new. Reconnected and damned if the same thing happened again. I found that the bad connection had also caused overheating inside the female harness producing a loose contact there. Replaced the contact problem solved.
When that harness melted on my 66 the alternator wire shorted over to the coolant sensor wire and backfed my gages apparently bypassing the instrument regulator as gas and temp gages would go full scale. My bulkhead plug and receiver ports were melted out and terminals shorting out various things too.
Lucky Lar
Well-Known Member
It said they were in stock, but who knows a lot of things are in short supply these days
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hoping it was a loose connection at the burned connector, i will keep an eye on it when i put the new one in
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hoping it was a loose connection at the burned connector, i will keep an eye on it when i put the new one in
Y07Roadrunner
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I found this post late, after you figured out the issue. I had the EXACT same thing happen in my '70 Hemi RR convertible. The engine harness was a "new" reproduction from M&H Wiring. The wires at the alternator junction over the right-hand valve cover shorted out and fed power to the coil as long as the battery was connected. The diagnosis was a bear, but once we found the issue it was a relatively quick fix. I've spoken to others who have experienced the exact same issues with the M&H harnesses....
Lucky Lar
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I have a new harness coming from M&H. Could you tell what the issue you had with the new harness was & what you did to correct it?
Y07Roadrunner
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There is a junction plug roughly halfway down the passenger-side valve cover (it connects the main harness to the alternator & coil harness). Several of the small wires that feed into this plug shorted against each other, which resulted in the coil having 12V at all times even with no key in the ignition! We had to separate the junction box and jump each wire individually to diagnose this issue. Like I said before, not terribly hard to do but very time consuming. Once the offending wires were identified we split open the (taped up) harness, separated the wires out, and (bypassing the plastic harness connector) simply soldered them together. You can tell that the integrity of the harness has been altered, so maybe I lose a few points at a show, but now I have the confidence that the wiring is fixed.
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IMO....The reason for the alternator DISCONNECT feature on only the HEMI powered cars, was to be able to disconnect or unplug the alternator connections to be able TO REMOVE THE VALVE COVER TO ADJUST THE VALVES. Sort of a compromised design that combines the field supply connections and the alternators output connections but MOST HEMI alternators only furnished either 37 amps or 42 amps and were within the capability of the hardware furnished. Just my opinion of course....
BOB RENTON
BOB RENTON
Y07Roadrunner
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That makes good sense! I hadn't thought of that before.
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