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nzarano

240z retrostat removal

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anyone have any tips to removing the retrostat in a 240z? was playing with it last week then i hit a bump and all of a sudden my interior lights were gone... want to pull it and see whats up but dont know where to begin... any advice would be appreciated

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You sure it's the Rheostat that's blown, and not a fuse? Also, try turning it all the way to one direction, and then all the way to the other a few times. Your connections could have corrosion on them. Sweeping through the full range could clean them.

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Posted (edited)

1. Don't just start removing parts without understanding the wiring for the lights.  Just a waste of time and you might create a whole new problem.

 

2. Download a Factory Service Manual (FSM).  It has a schematic and sections on the electrical system that you need to understand.  Check Hybridz or Google it

 

3. Download a schematic for your Z.  They are available on HybridZ and a number of other places on-line. Some members have re-drawn them in color. Check Hybridz or Google it.

 

4. More information is required when asking for help. Walk around the car with all of the lights on and report if any other lights are out.  Why? Because the interior lights share circuits with other lights in the car.

 

Clue:  A  bump followed by lights out.  Could a plug in the wiring harness come loose?

 

Tools required: volt meter and electrical schematic

Edited by Miles

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By interior lights i mean all the lights that light up the dash...

 

have tried moving the retrostat back and forth and still no luck...

 

All fuses were removed and checked. All taillights were removed and checked to see that all filaments were in tact ( i know some have 2..)

 

Someone pulled up to me the other day and told me my tail lights were out, checked and all the right lights come on when breaking and signaling but nothing is on when headlights are on.... does this help narrow the issues down / are they related?

 

I think with both of those going on it doesnt seem like a plug, maybe a short?

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Have you done this yet?

 

4. More information is required when asking for help. Walk around the car with all of the lights on and report if any other lights are out.  Why? Because the interior lights share circuits with other lights in the car.  Tells us what you see.

 

Just a guess, are the corner (running lights)  lights not coming on?

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The dash lights are on the same circuit as the marker lights, tail lights, and front running lights. All of these pass through the combination switch and out a single (rather small) wire in one of the connectors.

 

On my car, that pin on the connector is heavily corroded and the whole thing gets pretty hot due to all the current.

 

For troubleshooting, figure out what all doesn't work and trace the power from the source.

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Posted (edited)

Most likely a combo switch problem.  He should rebuild the switch. I had a similar  problem and found that solder joint had broken off the circuit board inside the switch.  We have a member (Dave) who rebuilds the combo switches.

 

Edited by Miles

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12 hours ago, Miles said:

Thank you for these!!! my right blinker has never shown up on the dash when signaling so hopefully can go through this and fix all of my electrical issues!!! If not back to the retrostat....

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Couldn't agree more with the advice above.  Have seen several members here, and on other forums, recently tackle electrical issues with a random, unsystematic approach....replacing components at random without any deliberate analysis or troubleshooting.  Just leads to frustration and lots of time/money spent on needless replacements.

 

BTW, if you determine that your issues are indeed caused by the gauge lamp dimmer rheostat, and if you don't care about the functionality of the rheostat, it can be removed from the system.  It's just a variable resistor.  I always prefer my gauges on full bright, so I removed the rheostat and jumped the two leads together....giving full current to the gauge lamps whenever switched on.

 

Good luck with it.

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low and behold the internet was right! checked the combo switch and there was major pitting and one of the little rubber caps on the springs was totally gone, tried following the headlight switch rebuild article but the thing was too gone.... ended up making things worse and now the whole things apart doesnt want to work.....looking for a new combo switch or just the little caps and that box with the tabs for a 1973 240z, posted in the in search of parts section too.... 

 

 

Thank you guys so much for the help! hopefully someone has these parts sitting around

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Posted (edited)

Contact Dave at the link I provided you. He rebuilds combo switches and has parts. He rebuilt my switches. Eventually my switch fell apart so I bought the last new OEM combo switch Black Dragon had for $300. Or buy up several old switches and rebuild one and keep one as a spare.

Edited by Miles

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