RD 690 electrical problems

[Jomorisn]

My 1990 RD 690S the volt gauge will drop like you shut the key off and then sometimes it will go back to charging properly sometimes if I turn the key on and off it will not like all the power to the cab is off even though the key is on  any and all help would be great thanks in advance John

[mackey58]

Maybe a bad key switch? 

[polracer01]

Try key switch or regulator under dash above the glove box or we had one this summer where we changed out all the ground bolts from on the block ground the alternator engine block and cab grounds... the later was doing the same thing yours is be charging fine then volt meter would drop off

 

 

[57 bcr]

The accessory relay should  be checked  out. It's the loud click  you hear when you turn the key to "on". They go out after a while. Common. Not really expensive or a tough  job. I would  start there. Al  

[Jomorisn]

I have replaced the switch and still the problem but thanks for your reply John

On 12/22/2017 at 9:40 PM, mackey58 said:

Maybe a bad key switch? 

 

[Jomorisn]

On 12/22/2017 at 9:58 PM, polracer01 said:

Try key switch or regulator under dash above the glove box or we had one this summer where we changed out all the ground bolts from on the block ground the alternator engine block and cab grounds... the later was doing the same thing yours is be charging fine then volt meter would drop off

 

 

Is that the one that looks like  Ford starter solenoid ? Thanks for your reply John

[polracer01]

Yes it is