Mopar Muscle Association UK

Dave999 wrote:

what did you test above?

alternator casing is at 11.9 volts when ruinning?

or you checked between the to-battery stud and earth when it was running and only got 11.9?

if it wasn't running i'd expect that. you are just seeing battery voltage



the ammeter bit is a red herring don't worry about that current takes route of least resistance

Dave

Yes mate as you said........Engine running, Battery connection post on the back of alternator and used the alternator casing as the earth.......had 11.9v.

At the battery posts (pos to neg) I was seeing mid 12's so that I would assume, even when running, is just the battery on its own.

After I adjusted the idle up a little, the same test above was showing 13.4v at the battery posts.

Spent an hour or so last night wire brushing the battery to body and engine to body ground wire, plus both headlight grounds. Will look at the inside the dash tonight and do the same.

Alternator arriving tomorrow, so will see if that changes anything on top of what I've already done!

Well.......This car is trying its hardest to stay in the garage for another year.

Well like most i try to be methodical and work through it, change a part and retest. Every time getting a different outcome.

Bought new alternator to put on hoping for a solution. Thought about checking the ground on the ignition module, so took it off to clean and found an interesting side affect of an overcharging car!

Well this expains the mess on the inner fender........



=



Lucky it didnt toast the car.......

So picked up a new module from Customvill and put that on too.

Outcome is 12.6 at idle and 15.2 max under load. So my old 74 alt was/is still a goodun!

Read a couple of Yank forums and think i've found the issue (here's hoping). As expected i suppose, its a breakdown in the wiring somewhere where its grounding out or touching other wires and sending false readings to the regulator thus falsly under-reading and tricking the reguator into uping the voltage and unknowingly overcharging at the battery.

Next step, to redo replace the wiring as per the MAD electrical install, whilst bypassing the Amp gauge (gotta drop and pull it out again..... ).

First real runs on my all new setup.

If it helps, I see 12.5 at the fuseboard when car off.
14.7 at idle.
14.8-15.0 when motoring good.

Doesnt go over 15.

My grounds are A1 - extra straps, clean surfaces, even dual feeds (one to engine, one to chassis strap) off the battery. Should be good.

morgan wrote:First real runs on my all new setup.

If it helps, I see 12.5 at the fuseboard when car off.
14.7 at idle.
14.8-15.0 when motoring good.

Doesnt go over 15.

My grounds are A1 - extra straps, clean surfaces, even dual feeds (one to engine, one to chassis strap) off the battery. Should be good.

Cheers Morgan......Found the culprit, oxidised, detatched connector that was badly arcing. Twas the feed wire between the alternator and the bulkhead connector.

Rewired the two field wires and temp sensor wire aswell as the arching had pretty much welded/melted all 4 together and thus fooling the regulator into overcharging the battery/Ignition system!

How the Dart isn't a burnt out shell I don't know!!!!

Anyway, followed the MAD (ammeter bypass) diagram, now hits 14.9 max (Reg Max point is 14.88), so all is good on the charging side!!!

Excellent. Numbers sound much better. Your melted ecu is
Yeah, the Mad guide is very good - although getting to the back of the ammeter to do a good join is a cow. I also ended up using the bulkhead connectors for the dash-loom, but draw is minimal so not a problem.
ignition runs straight off a new fusible link from the starter relay.

morgan wrote:Excellent. Numbers sound much better. Your melted ecu is
Yeah, the Mad guide is very good - although getting to the back of the ammeter to do a good join is a cow. I also ended up using the bulkhead connectors for the dash-loom, but draw is minimal so not a problem.
ignition runs straight off a new fusible link from the starter relay.

Had the dash out a few times now so got it down to 30 mins and the whole lot is out.

I bypassed the bulkhead connector altogether as the entire ignition loop is now on the drives side inner wing. Only part I didn't touch was the factory welded splice!

Decided that if I stuffed that I,d be basically disabling the whole car. So only have about 6 inches of original wiring at that particular area!

Great upgrade and piece of mind with the new Voltmeter I've added!

Respect. I gave up looking for the welded splice. Buried too deep...

Here's a bit of trivia for you. Doubtless the Daves would know the answer BUT today I observed a funny.
On the way to work (so 7:00am - cool air) Car is running 14.7 on idle, 15.0 on high speed. On the way home (26deg hot day) its 14.4 and 14.7 respectively. Go figure ! Either way, still in range. Odd though.

morgan wrote:Here's a bit of trivia for you. Doubtless the Daves would know the answer BUT today I observed a funny.
On the way to work (so 7:00am - cool air) Car is running 14.7 on idle, 15.0 on high speed. On the way home (26deg hot day) its 14.4 and 14.7 respectively. Go figure ! Either way, still in range. Odd though.

i'm sure i read somewhere that the voltage reg is affected by temperature, could be it ...

Dave is the voltage reg bolted directly to the body? I had the same issue & stuck some spacers behind it to allow a circulation of air around it. Never had a problem after I did that.

charger01 wrote:Dave is the voltage reg bolted directly to the body? I had the same issue & stuck some spacers behind it to allow a circulation of air around it. Never had a problem after I did that.

Mines all sorted Ade, but yes, mine is bolted directly to the bulkhead just behind the base of the brake servo.

Not had it out driving yet (MOT rectifications still outstanding), so not sure if I'd get the same issue as Morgan!

Its on my list of things to do as everything is stacked on the drivers side yet I have nothing really on the passengers side.......will be done as part of a future HEI upgrade!!

Not really an issue - just an interesting observation. Still all good my end.
Yes, I made a spacer so voltage reg sits clear.Plus an auxiliary earthing strap direct to the chassis ground. Would recommend to all.