1999 Mack RD 690S Electrical Issues

[wacopaving]

I have a 1999 Mack RD690S. On and off we have been having issues of the truck not starting some days. One day it is fine and the next it’s not. 
You turn the key on and you hear clicking like it’s trying to pop a fuse. A lot of the time it doesn’t even cycle through like it’s supposed to. Anyway, when you turn the ignition to “start” the truck, the dash lights flicker on and off, the tachometer spins a quarter turn and it just clicks and clicks. You may get a revolution or 2 but then it dies out and you have to shut the key off before trying again. All of the fuses and wiring under the dash has been checked. It all checks out fine. Getting around 12.9 volts on the batteries when checked. I checked all of the connections to the starter, solenoid, alternator, etc. it’s all tight and secured. I can’t seem to find the problem. We were working on it the other day and out of the blue it was fine again. Turned over and started up no problem. I keep tracing wires to find maybe something exposed and shorting out but I haven’t found anything yet. It’s really frustrating me because I know it’s something simple. Any help is appreciated as I continue to workout what the problem is.

[terry]

Not sure if that year has this, but check to see if it has  the accessory relay, on the older R models you took that panel off on top of the dash and it was right there, sounds like a loose connection on it maybe.   terry

[wacopaving]

Hey Terry,

I will check that in the morning but I’ve run through every relay and wire in that dash. Doesn’t seem to be anything in there. I replaced the starter solenoid on the fire wall. It’s weird because when I bypass the solenoid it cranks right over. Otherwise it won’t even turn over but 2 revolutions with the key. It just wants to click. It just seems like there’s a bad ground or short somewhere.