Electrical to-do list

[shrewboy]

I picked up a 78 Custom from the second owner (and he's had it since 1985) a couple of months ago, and have started to realize that I'm about to do some wiring work. Whether I wanted to or not.

I've been reading through some older posts about wiring, and it looks like the combo of the fuse box being melted at the fuse holder for the heater, along with the blower motor not working is a well known issue with these trucks. I also noticed that the ammeter is kinda in crooked, like maybe it's melted a little, and the gas gauge never goes beyond 3/4 full.

I'm planning to do the ammeter cut-out for sure. I'm also looking at pulling the heater blower switch and the associated wiring, replacing parts as needed, and I think someone mentioned installing a breaker in-line for when the blower is in the high position. If getting the current regulated doesn't help the gas gauge, I'll probably drop the tank and clean all of the connections. In the absence of other electrical problems, are there any other electrical must-do's that anyone can think of?

I did a little soldering in college 10-15 years ago, but I'm planning on picking up the introduction to soldering and electrical from MAD electrical to give myself a refresher. Beyond that, has anyone with limited electrical experience done some of the upgrades above? If so, was it do-able? I'd really like to do this myself, but I'd also prefer not to burn my truck up in the process? ;)

Thanks all!
Shrewboy

[old tired rebel]

I have been thinking about doing the same thing myself. I have downloaded the articles to my computer so I could have them while making the repairs. Thanks OTR

[75 Power Wagon]

I have done the ammeter bypass by myself, with little electrical background work.. Just take your time and make sure you understand why you are doing everything.. and you will be fine.

[Chump]

Get your parts first and lay them out and understand where you're headed. The bulkhead connector/s on the firewall are are problem area, you'll want to pull off the harnesses from the engine side and cleand the male terminals and inspect for heat damage and corrosion. Apply dielectric grease to them just before you snap the pluhs back in. If you do find any damaged terminals(male) in the harnesses be sure to check the corresponding terminals(female) in the bulkhead connector for damage.
The heater-A/C blower switch..replace.
Check the wiring harness at both ends for heat damage.
You can install relays to keep the high current out of the blower switch.
Install a headlight relay system.

[old tired rebel]

Get your parts first and lay them out and understand where you're headed. The bulkhead connector/s on the firewall are are problem area, you'll want to pull off the harnesses from the engine side and cleand the male terminals and inspect for heat damage and corrosion. Apply dielectric grease to them just before you snap the pluhs back in. If you do find any damaged terminals(male) in the harnesses be sure to check the corresponding terminals(female) in the bulkhead connector for damage.
The heater-A/C blower switch..replace.
Check the wiring harness at both ends for heat damage.
You can install relays to keep the high current out of the blower switch.
Install a headlight relay system.Looks like I have more research ahead of me for the fan switch and headlight relay system thanks for the heads up on those.

[Megunticook]

I just ordered a replacement switch made by Echlin for NAPA:

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=ECH&PartNumber=HC203&Description=A%2fC+%26+Heater+Blower+Motor+Switchht tp://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=ECH&PartNumber=HC203&Description=A%2fC+%26+Heater+Blower+Motor+Switch

You can get equivalents from other manufacturers. Echlin is usually pretty well-made (hence the high price).

[old tired rebel]

I just ordered a replacement switch made by Echlin for NAPA:

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=ECH&PartNumber=HC203&Description=A%2fC+%26+Heater+Blower+Motor+Switchht tp://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=ECH&PartNumber=HC203&Description=A%2fC+%26+Heater+Blower+Motor+Switch

You can get equivalents from other manufacturers. Echlin is usually pretty well-made (hence the high price).Thanks I'll go by there tomorrow with the part nuber you gave me. I hope they have one for a truck without ac.

[Megunticook]

That's an affirmative--my 318 runs only heat also, and they have plenty of those switches. Although the blower wiring may be identical in AC/non-AC varieties--my Dodge experience has all been heat-only.

AC's for sissies and old ladies, you know.

Mine hasn't arrived yet, can't advise you on installation at this point, but should be pretty straightforward. Then again, it gets to be a rat's nest under those dashes sometimes.

Or you discover that something ELSE is impeding your operativity.

[old tired rebel]

That's an affirmative--my 318 runs only heat also, and they have plenty of those switches. Although the blower wiring may be identical in AC/non-AC varieties--my Dodge experience has all been heat-only.

AC's for sissies and old ladies, you know.

Mine hasn't arrived yet, can't advise you on installation at this point, but should be pretty straightforward. Then again, it gets to be a rat's nest under those dashes sometimes.

Or you discover that something ELSE is impeding your operativity.I hope that's all it is unless it's the wiper motor.

[Chump]

If your wipers have stopped working, try running a seperate ground wire to the wiper motor case and see if it starts running again.

[old tired rebel]

If your wipers have stopped working, try running a seperate ground wire to the wiper motor case and see if it starts running again.Thanks Chump I will.The problem is I can turn on the wipers and they start working and then stop.Sometimes I can push on them to get them working again.

[Chump]

The actual ground strap on the motor looks like a flat brass feeler gauge like what I have hilited in the picture. the end with the hole goes on one of the rubber mounting bushings and gets a ground thru the mounting screw.

[old tired rebel]

Thanks Chump.