Doffer Posted January 29, 2013 Share Posted January 29, 2013 Im having an issue with my 1999 Mack RD688S truck. I hop into the cab and turn the key to ON and wait for the 6 clicks... after the 6 clicks, I proceed to turn it to the START position. Well, the problem I am having is every once in a while when i turn it to the START position, it will make a click sound from inside the cab (relay) Then i will loose all power to the cab. No radio, no lighter, no buzzer, nothing. I'm not sure what is remedying this problem... what I've done to get it to start in the past was clean the battery terminals for one time. I bypassed the battery shut off switch (Bolted it together ... no longer has a shut off switch), and Wiggle the harnesses around for the other times. It just randomly will come back to life and start buzzing. Its very frustrating. the batteries have all been replaced recently, and I confirmed individual voltages on each battery.If anyone has any thoughts, i would sure appreciate it. I really dont want to take it to Mack and have them fix it. For reference of the model, a picture has been attached of the truck Quote Link to comment Share on other sites More sharing options...
2stacksuperdog Posted January 29, 2013 Share Posted January 29, 2013 Check the connection to the solenoid and the starter Quote Matt Link to comment Share on other sites More sharing options...
Doffer Posted January 29, 2013 Author Share Posted January 29, 2013 The connection from solenoid to starter would cause the entire cab to have no power ? Quote Link to comment Share on other sites More sharing options...
farmer52 Posted January 29, 2013 Share Posted January 29, 2013 Ignition switch? Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment Share on other sites More sharing options...
2stacksuperdog Posted January 29, 2013 Share Posted January 29, 2013 I just thought of that it sounds like a bad ground. To check it take a pair of jumper cables and attach them to the cab and attach the other end to the frame and then try it and see what happens. If this is the problem, run a ground wire from the frame to the cab. Quote Matt Link to comment Share on other sites More sharing options...
thomastractorsvc Posted January 29, 2013 Share Posted January 29, 2013 maybe a circuit breaker, as you say it clicks in the cab then you turn off power while you are checking connections it resets. my two cents. Quote Robert"I reject your reality and substitute my own." Link to comment Share on other sites More sharing options...
Doffer Posted January 29, 2013 Author Share Posted January 29, 2013 I just thought of that it sounds like a bad ground. To check it take a pair of jumper cables and attach them to the cab and attach the other end to the frame and then try it and see what happens. If this is the problem, run a ground wire from the frame to the cab.makes sense. I'll check all this stuff out tomorrow when im down at the shop. Hope its an easy fix! Quote Link to comment Share on other sites More sharing options...
2stacksuperdog Posted January 29, 2013 Share Posted January 29, 2013 By the way that's an RB in the picture not a RD Quote Matt Link to comment Share on other sites More sharing options...
Doffer Posted January 29, 2013 Author Share Posted January 29, 2013 well i haven't had a chance to look at it yet! I had to go on a job this morning. I'll check out everything tomorrow. nothing going on as of yet Quote Link to comment Share on other sites More sharing options...
felicello122 Posted January 31, 2013 Share Posted January 31, 2013 check the circuit breaker ground on the left side firewall,and the starter soloniode next to the ground beaker[little black box]. Quote Link to comment Share on other sites More sharing options...
Doffer Posted February 7, 2013 Author Share Posted February 7, 2013 Well, I was looking around the firewall area under the hood and saw the starter relay was loose. I took the bolt out, cleaned up around it, and re-bolted it securely. Seemed like everything was good until I started driving it to a repair shop for weld repairs. While driving, first the volt meter started reading low (10V), then going about 55MPH, 16,000 RPM it was randomly cutting out (loosing power) to the engine, dash, radio, lights, heater. The dash needles were going from 55MPH to 0 then click sound, popping back up to 55MPH then 0 then stayed at 0 with no power at all. Pulled off to the side of the road, threw the 4 ways on. Which that did absolutely nothing..... and popped the hood. I had a vehicle following me, and I told them to pull up next to me and put jumper cables from the battery directly to the power on the starter. When I did that, I immediately got power to the cab volt meter was reading 14 and it cranked right over. Once it started, I sat for a minute, drove about a half mile, then it broke down again. This time I got pissed, and I took a ratchet handle and smacked the starter, and that gave it power again for some reason. I turned the headlights off and let it idle for a couple minutes, then started driving. This time, it made it the whole way to where I was going. One thing I did notice was that there was water leaking from the windshield onto the dashboard on the passenger side. I pulled the heater relay out and it looked wet underneath.Do you think that the water dripping down could have been causing me all these problems all along? There definitely is an issue with the charging system right now, but the alternator looks almost like its brand new. I have it at a repair shop right now to change out the radiator, 2 brake chambers, windshield, and rear drums right now. I told him if he can figure out the problem that would be awesome too. But any suggestions I could give the guy would be greatly appreciated Quote Link to comment Share on other sites More sharing options...
thomastractorsvc Posted February 7, 2013 Share Posted February 7, 2013 maybe, I would think unlikly through but it should be checked to see if it shorted, check the battery cables and end connections and the starter connections, if hitting it made a diffrence and you said the jumper cables provided power it is being lost somewhere the clicking I think is a circuit breaker, If it was me I would check all electrical connections and clean them for corrision and add some dielectric grease to keep out the moisture and corriosion.BTW I think the alternator is probably good but since they are working in the front have them test it then you know for sure. Quote Robert"I reject your reality and substitute my own." Link to comment Share on other sites More sharing options...
Doffer Posted February 9, 2013 Author Share Posted February 9, 2013 maybe, I would think unlikly through but it should be checked to see if it shorted, check the battery cables and end connections and the starter connections, if hitting it made a diffrence and you said the jumper cables provided power it is being lost somewhere the clicking I think is a circuit breaker, If it was me I would check all electrical connections and clean them for corrision and add some dielectric grease to keep out the moisture and corriosion.BTW I think the alternator is probably good but since they are working in the front have them test it then you know for sure.Yeah I told the Mech. not to spend too much time on the truck anyways because its going to be expensive with just the work thats being done right now. So he may not be able to find the problem. He said he was going to pull all the connections and clean them, test the alternator and check around the cab for bad grounds. Quote Link to comment Share on other sites More sharing options...
Doffer Posted March 1, 2013 Author Share Posted March 1, 2013 ended up being the alternator was bad, and the connection to the starter was bad. Quote Link to comment Share on other sites More sharing options...
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