Power flickers

[Will_Swe]

Hi everybody.

first of all i want to apologize if my English isn’t super..

I have a Valiant -69.
I fitted a 5.2 magnum in it.
Megasquirt 1 v3.0 fuel only.
Hei mod electric distrubutor.
Using the magnums generator and wired up with the newer style voltage regulator.

my problem is that the car looses all electrical power intermittently like 2-3 times a minute. Causing all lights to turn off, engine stall and picks up again, and ecu to reset. Last maybe 0,5 second. Drops down to 0 volts and back up again. But it’s enough to cause big problems when I try to map the ecu.

tested ground points by bridging them one by one directly to the battery, but no difference.

Put in a big nice positive cable through firewall and bypassed amp meter.

was running fine for 3x1 hour before problem started.

Any ideas?

my headlight switch is glitchy, but I guess that should only affect the lights?

any tips is appreciated!

William//Sweden

 

[67Dart273]

Start by reading this article, showing the pitfalls of problems with high current going through the ammeter circuit and the bulkhead connector

Catalog

You do not HAVE to do the mod exactly as they do. You can also fix the terminals or drill them out and run larger gauge wire "straight through" and you can use a bypass wire straight from the battery to the alternator. IF YOU do this put a large breaker/ fuse in that line as you are removing the protection of the master fuse link

IF YOU DO NOT have documents, you can download factory service manuals and aftermarket, 2 page diagrams (which are not as detailed, but can be easier to read than OEM) here from MyMopar:

Resource Library – MyMopar

Service Manuals – MyMopar

Aftermarket wiring diagrams. Again, the factory ones are more complete

Wiring – MyMopar

 

[67Dart273]

Since you seem to have done some of this, I would advise some serious testing before you run it much or at all. This can tear up electronics, ruin your EFI box

If you have access to a carbon pile load tester, put a serious load on the system AFTER the battery feed goes to the distribution points such as the fuse panel, ignition switch etc

Maybe you have a poor terminal connection in one of the cables. Since the vehicle wiring has now obviously been modified, difficult to guess just where this might be. Originally the main power takeoff split off the "welded splice" in the black ammeter wire, behind the cluster. This originally came off the ammeter, a few inches, and several wires split off a factory splice In fact the MAD article I references shows this "simply"

So if that part of the wiring still exists I would certainly put it on the suspect list. ALSO if you simply bolted the original ammeter wires together at the original eyelet terminals, one of the wire end terminals themselves may have failed.

 

[66 Valiant wagon]

I'm agreeing with a poor connection on one of the power terminals.

I recently swapped an engine in and I had a similar issue where I would hit a bump and the power got all flickery. Turned out in my haste to get the engine in I didn't tighten the power to the fuse box all the way.

Good luck!

 

[Will_Swe]

Thanks for the answers!

iv’e done the mod like in the pictures. Apart from bat + on alternator goes directly to positive on battery with 1 gauge cable. And cable through firewall is a 9 gauge. Connected to the cable from the splice going to amp meter directly. So bypassed the amp meter.

I’m going to the garage in the weekend and will continue checking for bad connections.. need to get a new LSU wideband to as it seems being toast. Showing full lean since the power problems…

 

[67Dart273]

Yeh I would try not to run the car until you find this. You can blow up a lot of expensive electronics. I would look for a bad terminal at a major wire connection

Draw yourself out a diagram of the major power distro and try to figure a way to put a load on the system to heat it up. If you can borrow an infra-red thermometer you should find it