Did you hook up the second battery? You need it for the Starter and the Glow Plugs.
Starter may be weak also but you need to make sure you have 2 GOOD batteries first.
Starter takes at least 1200 Amps to crank and most good batteries only have around 600-700 Amps. (Forget about what the stores tell you about the amp, they usually over rate them). That is why it needs 2.
If you don't have the second battery:
You need a long positive cable to go from one battery positive to the other battery positive.
The length depends on the route of the cable, the stock route is around 85-90 inches (> 7 ft) with side post battery.
The cable goes down to the half way down on the fan shroud, go up the fan shroud along the top and go down halfway again and sideway to the battery. Get at least a 2 gauge may be even bigger cable with a 3/8" eye battery lug.
Another negative battery cable to hook up the now missing battery to the engine block somewhere usually the intake stud.
You can even add another small negative battery to the body if it is not there.
1995 GMC Suburban:
PMD in Bumper
Leroy Diesel Flight System PMD
Leroy Diesel Oil Cooler Line
4" Warpspeed Exhaust
Kennedy Diesel LP/OPS Harness
Bosch Duraterm GP
Last edited by JMJNet; 03-04-2016 at 11:27 AM.