Need Help With Glow Plugs Keep Blowing Fuse 1987 300TD Wagon

[gvanhouten]

Well I just got the head all back together and replaced alot of parts. My problem is that when I turn the key the Glow Plug light does not come on and blows the fuse. I had replaced all 6 glow plugs(bosch) the wiring leads are a suspect the #6 glow plug had some insulation missing and so I used electrical tape and then shrink wraped it on top. The glow plugs where working great until I went ahead and grounded the raceway to the intake bolts.

How often does the relay need to be replaced as well as other sugested areas to pursue. I am so damn excited to hear her sing and can't believe this is in my path.

Car is a 1987 300td wagon. 186,000

Thanks!!!!

[gvanhouten]

Any help here???

[Jim H]

The relay is a switch, it only applies power. The fuse is a safety, it melts if there is too much current. The relay cannot apply current, only volts. The resistance of the GPs determines the current. Too little resistance, such as a rubbing wire or a short, means too much current and the fuse melts.

Re-check each lead, measure resistance to ground. 0.8 ohms should be the lowest for each GP. Anything less, and you may have found why the fuse melts.

[gvanhouten]

Replaced the relay no luck just popped another fuse. The wiring harness I guess should be next. Have to wait until I get it. The glow plugs are new. Is there anything else that it could be??? Any further help would be most appreciated.

[Dervman]

I had the same problem after replacing the Glow Plugs in my SDL. It drove me nuts for a while figuring out what was wrong. In the end I found that in tightening up one of the ring terminals on top of one of the glow-plugs it had turned just enough to make contact with the cylinder head, shorting out the supply from the relay and blowing the fuse. Once I found it and re-positioned the terminal, everything was fine. No damage to Glow Plugs or Relay.
Good Luck