I see them.
Post 118 Steve
Factory ammeter
- Thread starter Dartfreak75
- Start date
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Post 118 Steve
cudamark
Well-Known Member
Another area of high current draw, and where I've seen lots of melted wire and switches, is the dash blower motor. When those fan motors get some years on them, they don't turn quite as easy and the current demand goes up and strains an already borderline capacity. That's another component that's a good candidate for a relay system.
Thanks guys, on my phone and missed the prev post. Thanks!
carguy47
Well-Known Member
OK, cool. I thought maybe I didn't connect it.
When crimping wires into terminals, It's very important to make sure you use the correct crimpers. HF one size fits all will cause problems. You need to make sure you're using the correct lugs and dies. Some are insulation grip, some are conductor grip. The knowledgeable guys here know this, I'm trying to help the first timers. I wired 747s and KC46a's for years, for those questioning my knowledge. Use the right wire, terminals, and crimpers. Use a good quality dielectric grease. too.
Bingo! It's the higher amp alternators that fry the terminals. The original alternators were 35A, and the remans put out 55A minimum. So unless you are running your original alternator your terminals are probably overworked. I know someone who replaced his alternator with a reman, and a short time later the starter began to intermittently engage while driving down the street. The bulkhead housing had melted around the charging terminal, allowing the charging terminal to intermittently contact the "start" wire terminal. I have rewired 4 67-68 barracudas and found that every one had the bulkhead connectors slightly melted at the charging terminals.
BillGrissom
Well-Known Member
Reason for the "MAD Bypass", though that disables the dash ammeter. Some owners instead install a dash voltmeter. I added a shunt diode to my 3 1960's Mopars so that increasing currents begin flowing direct from alternator to BAT+. The ammeter is still active, but doesn't peg. My cars have the 1965 bulkhead connector with buss-bar feed-thrus for the higher ALT and BAT currents (retrofit to my 1964). Posted the details years ago.
The cause is not the alternator. It's the load. An alternator with potential for higher output only makes it worse.
A lower output alternator would not have saved the OP. If it was 35 amps instead of the 40 amps he observed on on the ammeter, the result would have been the same. SIW.
A lower output alternator would not have saved the OP. If it was 35 amps instead of the 40 amps he observed on on the ammeter, the result would have been the same. SIW.
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Thanks for this info! That sounds like a very clever solution, but I want to make sure that I understand it correctly. Did you put a high current diode in a wire path directly from your alternator to your battery, so the current would bypass the dash when the alternator voltage got to a certain level higher than the battery voltage? And, did you remove the 2 bulkhead connector terminals and replace them with solid metal feed--thrus?
BillGrissom
Well-Known Member
You can google my past posts with photos. Parallel-reversed diodes with a forward drop ~0.5 V (at ~100 A). I measured ~0.75 V drop in the ammeter circuit at ~50 A output. The diodes I used are rated ~200 A and need a heat sink (can be the copper wires). Don't try it unless you understand basic electricity and DC power. In my post, one reader who doesn't kept arguing with an engineer (me) about resistance, which he didn't understand. A diode has a curved voltage drop vs current curve, which can't be summarized as a linear resistance value.
The 1965 bulkhead has integral buss-bars for the high currents, instead of spade connectors (google images). I retrofit one from a 1965 Fury (ebay harness) to my 1964 Valiant (cut opening 1/8" taller to fit). 1963 also had buss-bars. Seems after going to connectors in 1964, which suffered melted-plastic issues, they walked-back to buss-bars in 1965. In 1966, they moved the wiper motor to the engine bay, requiring a 3rd row of bulkhead terminals, so dropped the buss-bars (perhaps pencil pushers too), so back to melted-plastic. But as long as it lasted thru warranty they had no incentive since new car buyers then changed cars every 3 years. I've seen later Mopars with bulkhead connectors for ALT and BAT but with much larger terminals for those. Adding solid wire feed-thrus is the "Fleet Bypass" which the factory did in taxis and Police cars. Some here did that by drilling thru those positions (or new holes thru bulkhead).
Seems around 1980's, most cars went to wiring bundles direct thru the bulkhead, at least in GM's I've seen at the junkyard. The bulkhead connectors were likely mostly for quicker assembly than maintenance. My 2002 Chrysler minivan kind of regressed to using many connectors at the bottom of the underhood fuse/relay box (still solid wires thru bulkhead). I am guessing that also was for easier assembly. But, causes corrosion problems from rainwater getting in those connectors (not me in CA, but in eastern U.S.).
Thanks for the great info! I'm going to read your past electrical posts, and use them as resources.
So a lot of folks have a gauge cluster under the dash, so I have been installing a high quality, modern ammeter (along with a volt meter) under the dash for some time. You can use he original ring connectors and then just leave the factory ammeter in the dash for looks. Between the ammeter and the voltmeter I can keep a close eye on my electrical system, just like I do with a mechanical oil pressure gauge and the factory idiot light.
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