Re: 74 Dodge fan problem


[Follow Ups] [Post Followup] [Dodge Power Wagon Forum]


Posted by Phil Bernard on Saturday, October 26, 2002 at 1:20AM :

In Reply to: 74 Dodge fan problem posted by Todd Wilson on Thursday, October 24, 2002 at 1:35PM :

Fuse and Circuit Failures


Several Forms ago there was a lot of discussion about premature fuse failure. Your problem is a text book case indicating a poor connection at the fuse . Several causes have been mentioned in various responses to your entry (rusty/ corroded fuse cap or terminals; poor or inadequate terminal tension; etc.)

In any electrical circuit a poor connection will generate heat. The heat is caused due to resistance being placed in series with the load . As the current “ I” or resistance
“R” increases the voltage drop “E” at the suspect connection will increase ( E=IR Ohms Law) The power loss at the poor connection will be dissipated in the resistance as the heat you describe.

The voltage at the load will be reduced also (ie. dim head lights, poor starter motor performance, etc.) Battery terminal corrosion is a good example.

The heat generated in high current circuits (heater fan, charging, AC clutch, etc. )can easily reach temperatures that will melt plastic wire, terminal, and connector blocks quickly. The heat can even melt the solder joint between the fuse element and the fuse cap. Excessive heat will also take the temper out of the fuse block terminals. As the heat increases the resistance will increase in a snowball effect until a failure occurs. In worse case scenarios a fire can result (your vehicle can burn!).

The firewall connector block is a prime source for electrical problems in conventional “D/W” series Dodge trucks. Water runs down the engine side wall and into the connector block. The moisture corrodes the terminals and causes a voltage drop which generates heat. The moisture can reach the fuse block also. I had a D200 given to me because it would not start. A large portion of this block had melted away at the amp meter terminal area. Almost all the fuse block terminals were rusted.

The basic rule for any electrical connection is keep it clean and tight!




Follow Ups:



Post a Followup

Name:
E-Mail:
Subject:
Message:
Optional Link
URL:
Title:
Optional Image Link
URL:


This board is powered by the Mr. Fong Device from Cyberarmy.com