• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

Electrical problems

reblawyer

New member
104
0
0
Location
Tupelo, ms
I have been trying to get my Deuce driven up to Tupelo from Hattiesburg, MS for a couple of weekends now. It's about 200 miles. Of course one problem after another as the vehicle has sat unused since March. I finally got it on the road Saturday and was doing pretty well until IT happened. It was dusk and the lights were all working fine. I looked down at the instrument display and thought it looked like the voltage meter was in the red. Thought maybe it was just stuck so I flipped the main switch, the one that controls all the power out. When I flipped it back on the headlights blazed like searchlights and then blew out. Simultaneously the cover went flying off of my heretofore inopperable fuel gage followed by a flame that shot out about 4 inches before going out. I pulled off the road and changed my underwear. Then set about investigating my problems. I discovered that the cable connecting my two 12 volt batteries had come loose and assume that this had something to do with my troubles also found that the brake lights are blown. Any thoughts?
 

Armada

New member
3,046
4
0
Location
Buick City, MI
the headlights blazed like searchlights and then blew out. Simultaneously the cover went flying off of my heretofore inopperable fuel gage followed by a flame that shot out about 4 inches before going out.
:shock: :shock: :shock: Pitch underwear is right!
 

cranetruck

Moderator
Super Moderator
Steel Soldiers Supporter
10,350
75
48
Location
Meadows of Dan, Virginia
Poor battery connections can (will?) cause a phenomenon called "load dump", electrical spikes at 100 volts or more. The result is a blown regulator and possible damage to other electronics gear.
 

papercu

Active member
2,930
31
38
Location
Baxley, Ga.
problem

Never heard of a "load dump" before, so I went "alookin" This is from another forum and I always take things with a grain of salt. BTW I love google. Wayne

The OP was about a car radio going out at times.

answer was

Electrical transients in automotive systems are not uncommon. But voltage spikes where you can immediately "see" effects on instrumentation indicate a problem.

Does he just notice the radio cutting out, or is the effect visible in other areas... like the instrument cluster for example?

If it's just the radio, there might be a problem with the harness/connector to the radio. Or, a loose grounding strap/bolt that is affected by vibration.

If it's happening in other areas (e.g., instrument cluster, A/C system, interior/exterior lighting, etc.), you may have a defective alternator. Does he ever see the gauges ever flutter or dip? Or does he ever notice the interior lighting suddenly increase in intensity when this happens to the radio?

"Normal" vehicle electrical systems typically exhibit a voltage around 12.8V (battery voltage w/ ignition off) or 13.8V with ignition on and alternator up to snuff). The voltage can vary between 9V to 16V depending on the battery state-of-charge and/or condition of the alternator. These are rough numbers, but you get the idea.

Most vehicle electrical and electronics systems are designed to tolerate and function "normally" with voltages in the range of 9V to 16V, and even 19V in some cases. 19V is pretty rare, and represents a failed alternator. Electronic modules are even designed to survive to 24V for several minutes (representing a double-battery jump-start), although normal functionality is generally waived until the voltage returns to normal.

Where am I going with all this... oh yeah...

The voltage regulation these days is built into your alternator. The battery itself acts as a giant capacitor that can compensate for large transient currents, but it's the alternator that keeps the voltage steady (or, tries to, anyway).

There is a phenomenon called "load dump" which occurs when large loads are switched on and off... high current items like headlamps and A/C system, etc. Load dump can also occur if the battery experiences a sudden disconnect (via loose/faulty wiring or terminal connections). This can be as high as 40V to 60V, but is very brief. Again, most electronic modules in automotive systems are designed to withstand this kind of (typically brief) transient.

Bottom line: Check, in this order...

1) Check all cables & connectors running from the battery

2) Get the alternator checked

3) Hope the problem is not buried too deep in some other part of the electrical system

Good luck!
 

cranetruck

Moderator
Super Moderator
Steel Soldiers Supporter
10,350
75
48
Location
Meadows of Dan, Virginia
RE: problem

For one of my articles, I took apart several regulators (the 25 amp) and made a schematic diagram based on that. They do not have any tolerance for load dumps. I added a large varistor to my regulator to provide protection. It's all in the article, boring reading I know. :)
The MX-7777 can absorb a load dump and should be used when intercoms and radios are onboard.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks