'67 D100 with bad electrical

My 1967 Dodge D100 pick-up has been plagued with electrical problems since last summer. It started with a strange smell (I found out later was the AMP meter burning) that would last for about 10 minutes every other day 2 or 3 weeks before the electrical system completely shut down without warning usually while sitting at a light. After letting it sit for a while (maybe 10 min. to 2 hours) it would start up and run for 5 minutes to 5 hours. If I started it in the morning and ran to 7-11 it will not start for at least 10 minutes and maybe 1 hour. When I turn the key absolutely nothing happens. No accessories work including lights and bypassing the starter relay will allow the starter to turn over but no spark to run the engine. While it is running it charges the battery. I change the starter relay, voltage regulator & resister block but nothing changes. After noticing the AMP meter is on fire one day I tear it out and seems to fix the problem but it starts dieing again the next day. I change the ignition switch and notice that when I play with the head light switch and turn the key in the ignition at the same time something catches and it starts up. I drive it like this for a week and then change the headlight switch and put in a new AMP meter. This fixes most of the problem, the truck no longer dies and the alternator charges the battery. The dash lights had never worked since I bought the truck and now they work but blinkers, horn & heater do not work. It runs like that for about 2 weeks until one day all the accessories shut down including all gauges (the things working are the head and tail lights, break lights and the low break warning light on the dash.) and the battery drains while running with lights on. By charging the battery at night it can be driven during daylight hours. I change the alternator that Shuck?s says is bad but does not fix anything and try another battery. Then one day it would not start at all and the battery would drain even when just sitting overnight. I noticed that when I pulled the headlight switch the parking lights (blinkers not blinking) would come on in the first position but in second position would go out when headlights came on. I changed out the headlight switch again and charged up the battery and it started right up. I drove it 2 miles and turned it off. It would not start again and I bought a new battery. When I turn the key the engine starts running but dies as soon as I let the key go back and disengage the starter. Bypassing the starter relay makes the starter turn but no spark starts the engine. I changed the ignition switch but still will not run. I have a wiring diagram and have started replacing some wires with no luck. Still runs only while key is turned all the way to start position. All accessories and gauges do work now when the key is turned one notch or backwards. It is a slant 6, automatic with no radio or cigarette lighter. I have changed the battery, battery cables, starter relay, AMP meter, ignition switch, voltage regulator, resister block, alternator, headlight switch, wire from alternator to voltage regulator and all fuses. Does anyone have any ideas or should I put a bullet through the engine block?

Reply to
toofarmike
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Reply to
DonStaples

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Reply to
Stormin Mormon

You definitely need a wiring diagram for the truck. Get the factory service manual, which has more info than you can imagine.

Reply to
Max Dodge

Get a new wiring harness before you burn that truck to the ground. You might check with the hot rod aftermarket companies for a generic harness if you can't find a repop.

Budd

Reply to
Budd Cochran

Back in those days the bulkhead connectors were a big headache. Decon the battery and pull the bulkhead connector apart, separate the places where the wires are burned and fused together, rewire as necessary. Check under the dash in the area of the instruments and see if the pack rats have eaten thru the wiring and caused shorts.

Reply to
Jeff Burke

get rid of the amp meter. you will most likely need to replace firewall bulkhead connectors and factory fuse block as they are corrodided/melted.

Link below shows how to bypass amp gauge on 70s Dodge trucks, should work on yours. I did this about 4 years ago to 2 79's and have had no problems since. Instead of fusable links you can use a slow blow fuses.

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Reply to
ygransom

get rid of the amp meter. you will most likely need to replace firewall bulkhead connectors and factory fuse block as they are corrodided/melted.

Link below shows how to bypass amp gauge on 70s Dodge trucks, should work on yours. I did this about 4 years ago to 2 79's and have had no problems since. Instead of fusable links you can use a slow blow fuses.

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Reply to
ygransom

Start by finding a factory wiring diagram (better yet, a complete factory service manual).

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shows it available on CDROM(#81-370-7350) for $65. If you intend to keep the truck, this would be anexcellent investment. If you don't intend to keep the truck, it adds aselling point!

A vehicle this old likely has oxidized connections almost everywhere. Disconnect & inspect every connection you can find. While some advocate eliminating the ammeter, it can be left in place IF it's not open-circuit and the connections are clean & tight. Connections thru the firewall are also problematic, particularly the two that connect to the 12ga wires. Even the *slightest* poor connection in these will cause problems. The dead giveaway is the melted/distorted housings for these connections.

"Then one day it would not start at all and the battery would drain even when just sitting overnight." The battery going dead on its own is symptomatic of a separate problem... either a bad battery, or something not switched by the ignition switch is draining it. Check the specific gravity of the electrolyte in the battery. Fully charged, all six cells should be above about 1.25 and close to each other. Terminal voltage should be above about 12.5V. If that looks good, connect the battery with a milliammeter in series, and you should see zero current flowing -- a cheapo Radioshack VOM will work. If you have *any* current flowing, start disconnecting (usually aftermarket or miswired OEM) items until you see zero load.

Bryan

Reply to
Bryan

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