Ammeter bypass

[72RoadRunnerGTX]

The big reason is the old wives tale about the ammeter bursting into flames and kidnapping the Lindberg baby.

I watched this video yesterday (thanks) and it made a lot of sense to me. I've been of the opinion that most cars don't need this, but it's not a bad option. Your video has me rethinking that.

There is so much confusion and misinformation out there about the charging circuits that it's tough for guys to know exactly what to do. I've even seen some really bad, burn your car down type things happening. For example, I've read of guys putting large fuses on small wires... Thus the wire would burn way before the fuses would blow. I tried explaining that one and common sense did not prevail.

One recently was using Home Depot wire to do a "bypass" (at least it was stranded). I quickly realized that trying to explain that automotive wire was built to take the flex and home wiring wasn't would have fallen on deaf ears and 10 guys would have defended using that wire.

Funny, I’ve been battling misinformation/misconceptions about this charging system since my days working at the dealers back then. More recently, on-line on the various Mopar forums for years. Amazes me how the myth of the “spontaneously combusting” Mopar ammeter just continues on and on unabated and people are still just eating it up. The old “If I read it in a magazine/on-line article or post, it must be true” syndrome. Sometimes I’m met with a lot of uneducated push-back.

Several more recent YouTube videos promoting this bypass without mention of the serious added risk are just outright dangerous. One guy shows what appears to be 4/0 ga cable connected at the alternator stud straight to a battery clamp bolt. Freely admits he sourced the “commercial grade” cable for free from his place of employment. Then gets belligerent when questioned about its safety in a comment.

Loading this charging system correctly seems to be another area of misconceptions, folks just can’t separate this system from everything else these days. Clamping everything to the battery then when bulkhead or ammeter connections fail, must be the ammeter that’s the problem.

I too, have had numerous conversations over the years about why solid core, or stranded, house wire should not be used in any moving vehicle.

 

[bronze turbine]

The way I see it, there's nothing inherently wrong with the design from the factory. The only thing I can see being a problem is that since all the power for the whole car goes through that ammeter, it could get hot and start a fire if the connections got loose or dirty. I think it's only a 30A alternator on those cars so not a lot of power goes through it anyway. Now when you add a lot of power consuming upgrades and upgrade to higher output alternator, you're going beyond what the engineers envisioned for that design. Chrysler engineers themselves addressed this over the years because I know by 1976 the ammeter didn't have the total power going through it and it was more of a shunt type thing or actually was a voltmeter labeled as an ammeter. If you did the update the way the factory did it I can only see that being a good thing. But, if you do a hack job there's no doubt you could actually be creating more problems then resolving.

 

[72RoadRunnerGTX]

The only condition where full vehicle loads run through the ammeter is when the engine is not running or running and the alternator has failed. During 99% of the operational run time, there should be little to no current flowing through the ammeter, only battery charging current, ammeter needle centered or close to it. For C-bodies the switch to a shunted ammeter was around ’72-73 as I recall.