[Goldenblack440]

Well it wasnt as bad as it sounds, but there was smoke - Driving in the rain, wiper switch working then not working, very thin wispy smoke coming from switch pod i think, not a good sight in your just-got- driving Challenger. Get home, turn off eng. , try and start again, huge power short, won't start, huge power drain when turn lights on or horn but dome light working normally. I pulled the negative lead and checked the resistance of the car -very high, so no direct short. Going out now to pull the switch pod. Something has shorted behind there. I hate electrical problems!

If anyone has had these similar symptoms - what was it? Thanks.

[dave-r]

I think you are just going to have to eyeball it and see what you can see in there. Hopefully it is just a worn wire or something.

[fbernard]

If anyone has had these similar symptoms - what was it? Thanks.

I would say the carbon potentiometer track inside the switch is probably toast (or is it a wound rheostat like in the dimmer switch?)

Never had exactly that but I had other symptoms.

On both Challengers (I have since rebuilt the column and replaced the dash harness on the hardtop), the steering column housing (aluminum section around the ignition switch) would get warm when driving.
VERY warm.
It stopped in the hardtop so I guess rebuilding the column with a new ignition switch did it. The ignition switch has a big drawback, safety-wise : it has constant power (no relay on that), and has a very thick power cable. It could easily cause major trouble if the power lead gets shorted to the column itself...

On the hardtop, the previous owner had to kill a fire under the dash with his T-shirt... (hence the harness replacement). Fun ! (actually, it sounded fun when he told me the story).

The solution I've found is always the same :
Open the driver door wide, move the driver seat back as far as you can, grab a flashlight, get on your back and wrawl under the dash. Look around, get a feeling about the harness and decide whether you can mend it or if it should be replaced.
The factory Service manual wiring diagrams (you can find them here, or on mymopar.com, print them and take notes on them too) are pretty useful too.

Areas to look at :
- the column switches (one small connector with big wires for ignition, another wide connector with several small wires for hazard, turn signals, horn, ignition switch light, key-in buzzer etc), most often butchered beyond recognition.

- the switch pod (the wires are pretty short - too short, actually, you can't even pull it two inches back before you're pulling on the wires). The problem here is mostly with the switches and potentiometers (worn, shorted, full of dust), not the wiring which is pretty simple.

- The fusebox (and especially the firewall side of it, with the two cavities for the charging wire that goes through the ammeter).

- the ammeter, with two big wires that must be secured in place and must not touch anything metallic around.

- the orange dash light wires, which could have been butchered to get illumination on aftermarket gauges (there are sockets for that)

- any wire that gets hot when ignition is on (usually that's one of the steering column's wires), usually split every 2 inches to supply power to an aftermarket stereo, drink heater, lighted fuzzy dice, and every other typically 80's electrical gimmick that may have been installed in your car by one of the 27 previous owners...

Of course, lying there on your back, fiddling with wires hanging above your head, you're bound to breathe a few grams of insulation dust which will fall on you (and into your eyes too) everytime you touch something - and sometimes when you don't. Ain't Mopars fun.

Some individual plugs and connectors can be bought from Year One, or you can get a complete dash harness from them (expensive but worth it - expect to spend at least 3 full days installing it).

I've seen new repop wiper switches for sale on Jim's Auto Parts web site (although I don't buy from them when I can help it). Very expensive, but it's always better than no repop at all, which used to be the norm for those switches.

Apparently there are 2 kinds of switches, even for the 3-speed wipers : variable speed switches and 3 fixed speed switches.

There, that's a pretty long post but there's a lot to say about electricity in our cars...

[Moparman1972]

The wiper switches are very finicky (3 speed ones, havent seen the variable speed deals.) I rebuilt all of my switches in that panel, but the wiper switch still gives me trouble. I parked the car one time after a rainstorm and noticed a quiet buzzing, which ended up being the wiper motor getting power with the switch off, and I'm sure it would have burned contacts/started a fire if I didnt yank the wiper harness out of the firewall.

Fbernard, or anyone else, are there any other sources for these switches besides this Jim's Auto Parts place? I had never been able to find repop headlight/dimmer/wiper switches. Putting in relays for the headlights will ease my mind a bit, but I still do not like having 35 year old electrical switches in my dash. That whole panel gets warm and makes me very nervous.

[Goldenblack440]

Thank you very much fellows, esp Bernard for the detailed long post. Much of what you say is relevant, but not to my car. As i have pulled the dash and wiring virtually to pieces and fixed the obligatory burnt wires. All wiring is (supposed to be) A1. And all tested. But the ignition switch i think you have a good point there - i have not touched that area, although key illumination wiring is all healthy. You are so right about the switch pod wiring- TOO SHORT! I rebuilt the dimmer switch myself (i was an Avionics Tech/ Instrument Fitter in the last century) and it has a new electronic Tacho. It has a new solid State Instrument Voltage regulator as well. However, Moparman, intersting what you say about the switches. I do hope its just the wiper switch shorting, but it has affected the big power users (lights horn starter etc). I have relays on my lights as well. I have not had a look yet, its after 1am, off to bed! It can wait till tomorrow.

BTW FBernard, when you refer to the Challenger as a Hardtop - i thought almost all were hardtops? Ie they have a wind-down rear window. Only the coupes had a fixed rear window and these were the budget 6 cylinder cars, the Deputy and the Challengers aimed at the budget conscious. That was what i always thought anyway.

Moparman, look at this site for the wiper switches. I know for a fact they rebuild every part of mopar instrumentation. I have dealt withthem before they are very friendly and great to deal with. http://rt-eng.com/mediawiki/index.php/Main_Page

RTE or Real Time Engineering. They have recently renamed themselves to DashWorx. You could do a Google search for that as well

[Moparman1972]

Thanks, that will go on my website list!

[dave-r]

BTW FBernard, when you refer to the Challenger as a Hardtop - i thought almost all were hardtops?

Unless you have a convertible as well.

[Jon]

Sorry, no help here but,,,,Would it be practical to install a fusible link on the ignition switch circuit? (under the hood if possible) Just thinking, that would be a better place to have a wire burning down than in the steering column or dash.

[Goldenblack440]

Unless you have a convertible as well.

True

[fbernard]

Sorry, no help here but,,,,Would it be practical to install a fusible link on the ignition switch circuit? (under the hood if possible)

Chrysler did it. All current produced in the car goes through the fuselink, which is located between the starter relay and the ammeter.
But the fuselink (if it is still in good condition) will let quite a bit of current through before it burns up.

On the other hand (and I've probably told this story more than once here), if the fuselink gives up while you're driving, you'd better not be on the fast lane of the highway, overtaking a truck, trying to get ahead of a pack of 20-something cars slowly merging from the right on a section of the highway which has no emergency lane, 10 miles before the next exit....

What could be done with modern technology is to use a small solenoid (ie 100A or more if the alternator can give more), and drive that solenoid with the steering column switch, instead of using the switch itself.


As for the wiper switch, I only discovered yesterday that there were some repops (several people in my club are looking for them), I'd always found nothing every time I looked for this before. I have not tried to replace this switch with relays or anything, though it could probably be done (the circuit description is in the MTSC book below)

I never deal with Jim's (once was enough), and I like R/T Engineering's products and customer service, so if they can supply switches or rebuild them, that's great.

I'll be looking for this myself soon, I'm tired of the wipers not parking on my cars.

There's quite a lot of useful info over on the Imperial club website, including this vintage 1970 repair guide for wiper motors :
http://www.imperialclub.com/Repair/Lit/ ... age00a.htm

and more of those tech books :
http://www.imperialclub.com/Repair/Lit/ ... x.htm#1970


Dave is right (ain't he always? ) when I refer to "the hardtop", it's because I also have a convertible.

[Goldenblack440]

Would it be practical to install a fusible link on the ignition switch circuit? (under the hood if possible) Just thinking, that would be a better place to have a wire burning down than in the steering column or dash.

Good point, i was wondering why they didn't have one. In fact i will put one in there myself during this stint of problems while i have the soldering iron out.

I have pulled the switch pod out. Oh, so much easier to get out than in!! less than 2 minutes Vs about 15-20min to get it in. Anyway, with the switch pod out there is major power now, horns and lights ok. A continuity test on the switch gives some weird readings. I am just in the process of working out how to manually hotwire the 3 speed wiper motor. First at the motor, then through the plug. (don't forget to spray soapy water on the windscreen so it doesn't dry scratch). The circuit diagram i have is for a Dart but it should be the same with wire colours and terminals. It can be confusing - you have to look at what the switch is doing with the earth and 12V, and it doesn't makes sense at first. I almost fell asleep tracing the path, but will see how that goes now.

[Moparman1972]

It is a nightmare to try to do at the switch. And it took me a bit to test the motor itself on the bench too. That is why I ended up trying to rebuild the switch instead of make a new one. Not fun....

[fbernard]

I am just in the process of working out how to manually hotwire the 3 speed wiper motor. First at the motor, then through the plug. (don't forget to spray soapy water on the windscreen so it doesn't dry scratch). The circuit diagram i have is for a Dart but it should be the same with wire colours and terminals.

Did you look at this?

[Goldenblack440]

Oh my golly gosh! Thanks! I wish i had seen that before i went out in the cold and dark! that was just what i wanted. Anyway, i did work it out finally - quite simple really. The motor works fine both at its own plug and then from the plug under the dash. I pulled that little eng bay loom off and cleaned the terminals and squashed them back down to give a tight fit.

I tested the switch and also had a spare - they both tested out exactly the same. I rang RTE (Dash Worx) in America and spoke to a tech. He said unfortunately they did not have any test info on the 72-74 Rallye Wiper switch, which is different slightly to the 70-71 Variable speed switch. I still have not found the problem - only what i think it was: an intermittant faulty switch. The plastic terminal block on the back of the switch body was a bit loose compared to the other switch i had, so i swapped switches. All seems to be working well now.

For a 3 speed switch though, the last two (slower) speeds look the same to me. It would be nice if the last setting was quite slow. The first setting is very fast, the next two are almost the same. Blame it on the 37 year old swicth.

RTE told me that he thinks a company called Van's Parts, or Van's Reproductions, was making repro's of these switches.

I was wondering though...looking at where the wiper plug in in the eng bay, surely in heavy rain the water would come through the top vents and near that plug, especially when stationary in pouring rain? I am inclined to make up a little tin hat to go around the top to stop this.

anyway, thanks all for you advice, esp FBernard for your useful long posts

BTW, you have a convertible...that explains why you said Hardtop.

BTW II, i had a close look around the start relay - yes, there is a fusible link there! Silly me.